Today i took the 450 for a drive, and it worked perfectly ( this was in the morning ). Then at about lunch, my friend and i was going to get something to eat, and the car had no idling. You had to have full throttle to start it and then keep the rpms high or else it died, and as soon as you stopped the car died, and once again it wouldnt start without full throttle, and it took a while too. I have no idea what the problem is:(. I was hoping anyone of you guys here could help me out. (Sorry for bad english)
What year is your 450 Bulba and is it d-jet or k-jet injection?
Its a 1975, and i think its D-Jet injection. Today i loosened the fuel hose and turned ignition on, no fuel was coming trough though. So i figured it was the fuel-filter that was jammed or something, so i got a new one. Still the same problem. So now i wonder if its something wrong with the fuel-pump. But it sounds normally when you turn ignition on.
I can't think of a reason for this bulba ??? Although it's strange that you say the fuel pump still sounds normal, I would be tempted to get another fuel pump, maybe borrow a second hand one to see if that makes any difference.
Yes im thinking of buying a new fuel pump too. But it also came to my head that some junk has blocked the hoses. I bought the car when it has been standing for 13 years, so tonight im gonna emtpy all the fuel from the car and blow the hoses clean, if that doesent work, ill go buy a new pump.
Probably crap in the inlet hose.
Also worth checking the fuel pump relay in the fuse box.
Bill
Now i was out, and i checked the hose from the fuel tank, and no fuel was coming out. So i tried blowing up the tank instead, and it was empty. I didnt get it because i fueled it up a few days ago with 20 litres, and since then it has only gone like 3 miles. Then i realised something. Before i thought the oil level was waay to high, and i was sure i put exactly the right amount of oil that was needed, So i emptyed 1 litre of oil. Checked the oil stick, it was a litte less, then i started and it was more again (This was before when it started). So now my problem seems to be the fuel goes into the motoroil. I have absolutly no idea how to fix this :( please help me! :(
Surely litres of fuel would not be going into the motor oil under anything but paranormal circumstances. Are you sure you haven't just got the return line? I would have a look around the tank for any fuel leaks, as the hoses can rot and spring massive leaks. If you think the problem is fuel related, you should concentrate on the fuel system and check everything. What reading is displayed on the fuel guage? These are some things you should check. :)
Tim
ive checked everywhere for leaks already, and its no leaks anywhere. I checked both lines. No leaking in the tank either. Also it spits a LOT of fuel out from the exhaust. But the oil level on the stick gone from a little below max to about 1,5 cm over max. And thats a lot, that happened after we gone those 3 miles. ANd it smells almost only fuel from there too, and the engine is starting to sound wierd when you try to start it.
Hi Bulba. It seems you know what you you're doing so I hope this doesn't sound condescending but my first thought about the increased oil level is that you might be checking it too soon after running the engine and getting a false reading. Although it should measure less as oil drains back to the sump I find the dipstick tube comes coated with oil a little way up after running the engine possibly due to blow by gas pressure and oil moving around in the sump. You need to let the engine rest for say 10 minutes, take the dipstick out, wipe it, then put it back in momentarily and pull it out again to measure.
If you are doing this I'm clueless about the increase in oil level and can't think of how the fuel would be getting in there. Even if the injectors were pouring fuel in somehow I would assume most would exit the exhaust.
Anyway, back to the main problem, I can't answer why there's no fuel coming through the lines when opened up but there's a few observations that you've mentioned that make me think MPS (manifold pressure sensor).
- poor or no idle
- WOT (wide open throttle) to start it.
- running rich when it does run (exhaust smells like fuel so does oil)
Below is what it looks like, it sits on the left hand side on the inner guard. You need to make sure there's a vacuum hose attached to the "sensing port" and also connected to the engine towards the firewall. If it is connected and intact, for a rough test, pull the hose off the sensing port then using your mouth (or a vacuum pump with guage if you have one) suck on that sensing port and block it with you're tounge. See if there's a leak. If there's a big leak and you're tounge wont stay on the sensing port your car will misbehave like what is mentioned above. The only cure is to replace the MPS with a good second hand one. New ones are very expensive.
Also have a look at the following thread. It's got a couple more links at the top of first post but especially the second one has a lot more info about the MPS.
http://forum.w116.org/mechanicals/manifold-pressure-sensor-d-jetronic-repair-attempt (http://forum.w116.org/mechanicals/manifold-pressure-sensor-d-jetronic-repair-attempt)
(http://img224.imageshack.us/img224/9359/manifo670d53254in.jpg)
(http://img214.imageshack.us/img214/2618/mpsmedium2mp.jpg)
But the problem of the no coming fuel is solved. Its because all the fuel is mixing with the oil or going out the exhaust. And also a little goes the way it should. So the tank goes empty really really fast. I didnt understand how i only could go 3 miles on 20 litres. Thank you anyway. Now back to the oil problem. Ive waited when i checked the oil. I checked the morning after just to be real sure. Now i called my old man up. He said he had the same problem with his and that it was an injection problem. We have som bosch injection specialists here in town so im gonna go there today and check prices if they would look for the fault. And also just hear what could be the problem. I really hope its not too expensive, i just put out like 800$ on the car to get it legal to drive :P
Now ive been to the bosch specialists. They had cars in with the same injection, same problem, they looked for faults in 3 days then gave up. According to them, the D-Jet system was just a prototype but it was too problematic so then they changed it to the K-Jet. They coudlnt get much information from Bosch eiter, just two A4 papers with rubbish. And they refused to take on my merc. A friend of my steph father told him that it still could just be an electrical problem, so i guess i have to check out everything electrical first, or else i have no clue what i should do. :(
Could be as simple as an injector that is stuck open.
Pull plug wires one at a time until you find the cylinder that does not effect the idle. Check for proper spark on that cylinder. If it's good, I'd replace that injector.
Could also be as simple as a mixed up firing order. Track down each and every wire, maybe have some one watch over your shoulder.
My Renault 12 estate drained the tank into the oil pan due to a bad chingas in the carb combined with parking it nose down hill. Never ran the same after that. Until I rebuilt it due to the spun rod bearing that is. ::)
Michael
If you want to know nearly everything there is to know about Bosch fuel injection, try to find a copy of this book.
http://www.bentleypublishers.com/product.htm?code=GFIB&subject=25
Michael
Thank you Michael, i will look those things up! :D
D-Jetronic was not simply a prototype and was widely used on European cars of the era such as Volvo and Mercedes-Benz, as was K-Jetronic. The system was well-sorted and very advanced at the time. I think the "Bosch specialists" simply couldn't be bothered.
It does sound like you could have some injectors stuck open...
Tim
Thats what they told me, but i noticed too just now when i looked up som information on the system that it had been used on many more cars then just mercedes.
Porsche, VW, there's quite a few. I'm still amazed the injection specialist wouldn't work on your car. >:( . They're lazy, it's not rocket science. Whilst there is specific testing equipment for d-jet, any experienced shop will be able to use a scope, a multimeter and a vacuum gauge to test every component. If injectors are the problem after all, any shop (even lazy ones) ::) should know how to test the spray pattern and quickly tell if an injector is stuck open.
If there is a Mercedes Club in Sweden or a Swedish Mercedes forum, I would approach them and ask for recommendations of what mechanic to visit.
First my steph dad is gonna check it, hes real good at almost everything that has to do with engines and cars. Even though he never touched a merc before in his whole life, hes done a lot of work on mine. Then if he cant find anything. I was think maybe if i change the oil, then fuel it up and use som injector cleaner. Or else i have to hire someone to do the work.
Here's a quick tip for checking the injectors before you do anything else. Whilst the engine is running you should be able to hear each injector "clicking" as the solenoid operates the plunger and valve.
Use a long screw driver placed on the injector like shown in the photo below and put your ear on the end of the screwdriver. (or you can use a mechanics stethescope if you have one).
You should hear each injector clicking away at a regular pace. If you can't hear an injector operating it could mean that the injector is stuck open but keep in mind it could also mean it may be resting at a closed position due to an electrical fault.
(http://img82.imageshack.us/img82/1410/28082008498al9.jpg) (http://imageshack.us)
Thank you, i will try that but now its raining like the sky is falling down. Anyway today i changed the oil, fueled it up and put some injection cleaner in it. So now atleast it runs. But i will check that screwdriver thingy tonight if it stops raining :)
I couldnt try that with the screwdriver, because i have no idle and when someone is giving it gas it vibrates to much. We made a test drive today, and its obvious that it gives to much fuel, its just black smoke coming out of the exhaust when youre driving. Tonight were going to remove all of the injectors and check them.
I tested my injectors by just take them out (easy) and sucking air backwards throug them at the same time as I gave it wery short pulses of current from a 5 volt battery. Don't apply a constant current because I'm afraid that they can get to hot.
Before you do this you could unplug them and measure the electrical resistance on the injectors whitout having to dismantle them.
/Niclas
Thank you niclas, that doesent sound too difficult =) By the way i was thinking if i could buy some "universial" injectors, but i dont get this with the cc? Should the injectors be the same cc as the engine or what? Please fill me in, haha :)
Today i checked the injectors, all of them worked perfectly! And then a bit later, this wierd guy came from nowhere, and asked if i had problems with the car, i told him yes and then told him what the problem was. He told me that his former boss had the same problem with his 450, and it was an easy problem, though it took him a very long time to figure it out. He didnt remember exactly but he thought it was a hose or something he replaced. And also he tipped me about this guy living pretty close to me, who helped his boss with the problem. So im going to see him this monday, maybe he can help! Or else im ready to start crying, hahaha ;)
What about a burst pressure regulator diaphragm allowing fuel to be sucked in by vacuum?
and/or
Faulty temp sensors allowing max enrichment all the time. 8)
Try removing the vacuum fitting off the pressure regulator and look/smell for fuel. You could also look down in the plenum chamber beneath the throttle housing for signs of excess fuel.
Tim
Now i checked almost everything possible, ive asked people who have worked with these cars their whole life, no one can come up with anything. But now i realised what the problem must be, the piston rings. Thats way to much work for me to do on my gravel driveway. I dont know anyone with a garage and i dont have the money to let a professional do it. Im hopeless, so i guess its time for my old benz to go to the graveyard. :(:(
bulba, that's no good. :( Have you done a compression test yet? I thought around 145psi is a minimum and 150-160 psi was normal but the library says 8.5bar or 123psi is normal. Maybe that's for a low compression ratio engine. Either way, it's worth checking the compression on all your cylinders before blaming the rings. http://handbook.w116.org/Engine/107/M117_45/01-010.pdf
no i havent done that yet, im waiting for my friend to bring the tools. But i cant come up with any other reason. The only way for the gas to get to the oil is through the piston. But i will do a test to be real sure.
Okey now ive done a compression test, these are the results:
cylinder 1: 9 bar
cylinder 2: 10,7 bar
cylinder 3: 10,3 bar
cylinder 4: 17 bar (this one drenched the compression tester in fuel too)
cylinder 5: 11,4 bar
cylinder 6: 11,2 bar
cylinder 7: 11,1 bar
cylinder 8: 11,1 bar
So all of them are too high according to w116 handbook.
Then it's defenately a fuel related problem, not the piston rings. If it would be something wrong with the piston rings the compression would leak out there cousing to low compression readings not to high.
Soo relax, it's seems tricky but it's going too bee a lot cheaper than dissamling the whole engine...
Maybe the fuel regulator is broken or mis adjusted cousing the fuel to flow freely in to number 4 cylinder and far to much into the others too?? I guess that you could get too high fuel pressure if the return fuel line is stucked too.
Borrow a fuel pressure gauge is my best guess for the next step in the investigation.
/Niclas
I'll race you some day!
Thats true! Cant understand why i havent thought of the fuel return yet, i will check that tomorrow. Where on the car can i find the fuel regulator?
hi bulba, they're brilliant 8) I can't find any other reference to what the compression should be but I got 9's and 10's in the 350 from memory. I think your's are fine. ;)
However, number 4. Firstly, you've noticed there's liquid fuel in the cylinder. That fuel is thicker than air so it virtually blocks any gaps between the rings and cylinder. The result is that you get a huge jump in compression like the 17bar you measured. There's either something wrong with that injector or the wiring to it. Has to be the injector though because the injectors work in pairs 1 & 5, 2 & 6, 3 & 7, 4 & 8. So you would expect number 8 to be playing up too but it's not. Try another injector in 4.
This is looking promising 8) 8) 8)
Thats true, it must be the injector itself considering the others work almost perfectly. hmm, im guessing an injector is very expensive, but still, much cheaper, and much less work then taking out the whole engine and change piston rings. :D im going to try put another injector in nr 4 just as you tipped me. I have so little time now since school started. I have to agree, it looks promising. I was just about to give up. :D But im still stuck at the problem why it only runs on about 4-5 cylinders if the only injector broke is nr.4 .
Quote from: Bulba on 09 September 2008, 08:21 AM
But im still stuck at the problem why it only runs on about 4-5 cylinders if the only injector broke is nr.4 .
Oh yeah, I forgot about that :( I could guess and say that if number 4 injector is stuck open that it robs pressure from the other injectors causing the other cylinders to misfire but I really doubt that a stuck open injector could drop the pressure that much. Who knows, maybe that is what's happening. is there any possibiblity of trying a second hand injector perhaps off a wreck if there's a wrecking yard near you. That maybe the cheapest option, grab a few second hand ones if you can.
Its hard to find for my model, i was promised a good shape engine from a friend, but he gave it away to another friend of his. And in the junkyards they only have injectors for 280SE. So i dont really know where to find a second hand one :(
I dont know if im ready for these cars yet, financially. Even though i love them and have many memories from them i think it has to wait until i get a job :( And im gonna buy a nicer one. So now i dont know if im going to keep my 450 or sell it. Anyways, im not going to put any more money at it for now. :( whether i like it or not, the gas prices are to high here in sweden, and it only brakes down all the time. :(
1, unconnect no 4 injector electrically by just pulling off the contact. Test start. Price 0kr
2, unconnect no 4 injectors hose and plug it. Test start. Price 0kr.
3, check that the return fuel is not stucked by blowing in it. Test start. Price 0kr.
4, reduce fuel pressure by adjusting the screw un the fuel pressure regulator. Test start. Price 0kr.
/Niclas
OKey i will check that. I decided too keep it, but take a break from it. Soon winter comes and i have to put it away anyway. But i wont give up!
Now im ready to get going with this car again. Ive had myself a nice vacation and also worked a bit to get some more money. I was tipped of this guy, living a bit on the country side pretty close to the city i live in. Apparently he is some kind of expert on old mercedes escpecially from the 60s and 70s, and he has helped many people who couldnt get help from workshops and such. Now im going to change the oil again, unplug the fuel pump and run a new compression test. Then im going to go talk to that man, and after that i will see what happens.
Where do you live? I know a great old man in Trollhättan who probebly is born in a Mercedes...
His shop is just open one day a week unfortionately.
/Niclas
I live in Örnsköldsvik, so its a pretty long way down there :D
Did a new compression test today without the fuel pump. These are the results, its looking positive :D
1. 8,5 bar
2. 8,5 bar
3. 9,1 bar
4. 9 bar
5. 11,5 bar
6. 11 bar
7. 11 bar
8. 9,7 bar
So i guess that injector nr 4 is broken then ;) Or what do you guys think?
So with fuel pump _________ versus ___________ without fuel pump
cylinder 1: 9 bar 8,5 bar
cylinder 2: 10,7 bar 8,5 bar
cylinder 3: 10,3 bar 9,1 bar
cylinder 4: 17 bar 9 bar
cylinder 5: 11,4 bar 11,5 bar
cylinder 6: 11,2 bar 11 bar
cylinder 7: 11,1 bar 11 bar
cylinder 8: 11,1 bar 9,7 bar
I think you're going about it the right way bulba. ;) test the injector off the car if possible and check the wiring too but I'd imagine a new injector would be the way to go.........steal one if you have to 8)
I will check for prices on wednesday, if i buy it from mercedes i think it will be expensive as hell, so im gonna check with the local bosch store first :D
Great work Bulba!
there are usally several people selling used parts to these engines in Sweden since the rest of the car seems to rust away in our climate.
I've seen whole engines for the price of one new injector...
/Niclas
Quote from: Niclas on 05 October 2008, 02:06 PM
Great work Bulba!
there are usally several people selling used parts to these engines in Sweden since the rest of the car seems to rust away in our climate.
I've seen whole engines for the price of one new injector...
/Niclas
Sounds like a new one is kinda expensive then, do you have any information on prices? The best would be if i got hold of an engine thats pretty close to where i live. My stephdad keeps insisting on that it could be an electric disturbance somewhere in the injection system so he wont let me buy an injector until i cleaned all the contacts up. And i cleaned everything under the hood but he thinks it could be something somewhere else on the car. So i thought i ask you guys, is there some contact that could disturb the fuel system somewhere else on the car exept under the hood?
Quote from: Bulba on 05 October 2008, 02:47 PM
My stephdad keeps insisting on that it could be an electric disturbance somewhere in the injection system so he wont let me buy an injector until i cleaned all the contacts up. And i cleaned everything under the hood but he thinks it could be something somewhere else on the car.
I can understand that it will be very frustrating should you buy a new injector only to find out nothing chnages. I can't really think of what else to check apart from the earth points (tan coloured wires).
BUT! I had a somple brainstorm. Why not just swap injectors 3 and 4 and drive round for a while. Come back and do another compression test. If number 3 cylinder is now too high and number 4 normal then it has to be the original number 4 injector that is faulty and the elcetrical connections fine. As Niclas would say, price for this simple test 0kr 8)
Actually it isnt 0kr since i have to buy new oil to :) anyway i promised my stephdad that he could take a look, im still gonna check for prices tomorrow though =)
Today i went to the bosch store, but they didnt have any, couldnt order either, so i guess i gotta buy it from mercedes. Wich i owe 800 kr (110,70$) for a ignition cable i ordered but never picked up, haha :P
Still I would recommend you to just unplug that injector. It's very easy just loosen the four clamps on the short hoses on the injectors and pull the tube right out. Then replace number four's hose with a short plugged one. Put the other three hoses back and test start.
Or swap them and do a compression test as Oscar said, but that would take a few more minutes...
I found this guy who has some 450 parts: http://www.blocket.se/vi/18418148.htm?ca=16_s
/Niclas
Yesterday my friend told me about a customer he had that told him that he had an injector problem with one injector staying fully open all the time, and he changed the controller box and the problem was gone! So i decided to check mine too. I started out in the engine bay(if thats the english word) and found out that that rubber thing where the hoses go through from the engine bay to the rest of the car was removed due to another wire that was pulled trough there! So when i finally found the controller box, everything was very moist, and there was even water in some places. Im so mad att the previous owner, because the wire he removed that rubber thing to pull trough was for an thermometer wich wasnt even plugged in! So anyway what do you think, do you think that the controller box can be damaged by the moist? I was thinking too, even if the new compression test was better, some of the cylinders was still pretty high.
I uploaded some pictures too. (couldnt get them to work isntantly, so i just put the link here...)
http://img407.imageshack.us/my.php?image=img0439ye6.jpg
http://img440.imageshack.us/my.php?image=img0440yc0.jpg
I wiped up most of it but you can still see traces of moist.
I suppose it wouldn't be too out of the ordinary to suspect moisture inside the ECU (controller box) is causing an electrical short and an injector to stay open. Either moisture is causing the short or has led to a capacitor or something similar to fail inside the ECU leading to a constant voltage to the injector.
Have you got a test light? If you pull the plug off the injector and put a cheap test light onto the plug contacts you should be able to see the light pulse as the ECU delivers the signal to the injector whilst the engine is running. If the light stays on and doesn't pulse, then you can blame the ECU.
I once had a problem whereby I tried to clean my engine using a high pressure washer. I got water everywhere over the engine. The ECU was ok but the next day when I tried to start it the engine wouldn't go. I left the bonnet up and the engine facing the sun to dry it out. I couldn't see any moisture anywhere after a while but it took a week or more for a few cylinders to start firing and a few more days after that in the sun again before it was back to normal. Moral of the story is that moisture can be a real problem so it may be worth taking your ECU out and letting it dry in the sun as well.
I dont have a test light, but i should be able to get one. I will try and dry it asap, but its so bad weather here now.
Lucky you found the loose grommet and the resulting ECU moisture because even if it's not the cause of the current problem it would be trouble down the track.
While I'm sure you are enjoying yourself and learning a lot about D-Jet injection you seem to be jumping about from one possible cause to another without eliminating any of them.
You know it's an injector delivering too much fuel, the possible causes are faulty injector, ECU or injector wiring.
Start with the easiest thing, disconnect the injector and run the compression test again. If the compression is the same it's the injector, if the compression returns to a more normal figure the injector is fine, the problem is the ECU or the wiring.
So please, please do this simple test before doing anything else and post the result.
koan
Quote from: koan on 17 October 2008, 06:24 PM
Lucky you found the loose grommet and the resulting ECU moisture because even if it's not the cause of the current problem it would be trouble down the track.
While I'm sure you are enjoying yourself and learning a lot about D-Jet injection you seem to be jumping about from one possible cause to another without eliminating any of them.
You know it's an injector delivering too much fuel, the possible causes are faulty injector, ECU or injector wiring.
Start with the easiest thing, disconnect the injector and run the compression test again. If the compression is the same it's the injector, if the compression returns to a more normal figure the injector is fine, the problem is the ECU or the wiring.
So please, please do this simple test before doing anything else and post the result.
koan
I did a compression test without the fuel pump, shouldnt that give the same result as if i unplug the injector? You can see the results in the bottom of page three.
Quote from: Bulba on 18 October 2008, 05:41 AM
I did a compression test without the fuel pump, shouldnt that give the same result as if i unplug the injector? You can see the results in the bottom of page three.
That confirmed the problem is excess fuel from the injector but not what is causing it. Is the injector stuck open from some internal mechanical problem, is the ECU commanding the injector open constantly or is there a problem in the wiring to the injector forcing the injector open.
koan
STOP VACILLATING (evidence of a looming mental vasectomy) and buy beg or steal a few USED injectors and quit trying to THINK! Fix the damn thing!
Melt the goo out of the old one (or ruin it) by performing an unimaginably toxic and hazardous pressure-flush using the nastiest solvent you can find. Use your mom's best towels or your wife's favorite gardening gloves while doing this. It will improve the karma of the repair.
Once you've proven that you can either burn off most of your hair or ruin the existing #4 injector, stick ANOTHER INJECTOR in that HOLE! Hey, that way it will match! Your other 7 are USED and a new one is a waste of MONEY... junkyards and we fellow 116ers pretty much give them away.
SOMEBODY SEND THIS POOR GUY A HANDFUL OF INJECTORS (three is a good number - as hey, it is after all not a known good part)
Remember - GOOD nuts and bolts are La Fasteners... simple and functional. BAD nuts and bolts are Le f*cking headless irritating vacation-ruining pains in the *rse...
You sir, have one female injector on your hands. Stop pandering to her need to use you like a human feminine hygiene product, pull the string and GET La INJECTOR superbe. When in doubt, pull it OUT!! (replace the darn thing!) I swear this thread is wearing the pixels off my monitor!
THEN:
You will rejoin us in the ranks of 116dom - the land of we... (http://www.nsfw-comix.com/char-manly.gif)
Manly Men - In this day and age of political correctness (read: pussies), masculinity is a confusing and dangerous issue. Heterosexual men and boys of today find themselves in need of a role model who isn't a pussy, and that role model is the male chauvinist whom male chauvinist pigs wish they were: Manly Man. Manly Man once took on Chuck Norris and Maddox in a fight and won by staring at them until they turned gay and made out with each other, this distraction allowing Manly to punch them into orbit, where they still are to this day.
Quote from: koan on 18 October 2008, 06:00 AM
Quote from: Bulba on 18 October 2008, 05:41 AM
I did a compression test without the fuel pump, shouldnt that give the same result as if i unplug the injector? You can see the results in the bottom of page three.
That confirmed the problem is excess fuel from the injector but not what is causing it. Is the injector stuck open from some internal mechanical problem, is the ECU commanding the injector open constantly or is there a problem in the wiring to the injector forcing the injector open.
koan
This is true!
Personally, without the proper testing equipment I'd still swap number 3 and 4 injectors then see if number 3 cylinder now has raised compression and number 4 has normal compression similar to what it was without the fuel pump running. If number 4 cylinder is normal and number 3 cylinder higher, the ECU and connections are fine and the original number 4 injector (now in number 3 cylinder) is faulty. Do what John says and replace it.
If however cylinder number 4 is higher, then you can start blaming the leads and or ECU.
I tried to test with test lamp today without any result at all at any of the injectors. Does the engine have to be running? Shouldnt the injectors still pump in fuel when you turn the ignition? Yes, i will try to switch them if i dont get this test lamp thing to work ;)
Quote from: Bulba on 21 October 2008, 12:54 PM
I tried to test with test lamp today without any result at all at any of the injectors. Does the engine have to be running?
Yes
Quote
i will try to switch them if i dont get this test lamp thing to work ;)
Forget the test lamp, just swap the injectors and do the compression test again.
koan
Ditto. 8)
Okey, i will do that then. I will hit you up with the results later. Can take some time though, because i have to borrow my friends compression tester and he lives kinda far away and i dont know when he comes to town next time.
Havent got hold of the compression tester yet.... But this evening my steph dad checked everything, and when he opened upp the ECU he noticed that one contact was pretty loose. So we cleaned it up and put it back properly. But then when we was going to test start we saw that the thread in one of the holes for the spark plug was broken :( so now i have to find some thread-tool with the same thread as a spark plug to fix it. Then we can test start, and maybe the loose contact is the problem, who knows?
Now the compression test is made, and it still has the same results as the first time even though changed injectors. SO i guess the ECU is the problem!
If you have ensured that all contacts are clean and that the wiring to the suspect injector is 100% functional, then I would suspect ECU as a possible source of the problem. You should also ensure that all ground connections are showing minimal resistance too, if you haven't already.
Tim
Quote from: Bulba on 27 October 2008, 08:10 AM
Now the compression test is made, and it still has the same results as the first time even though changed injectors. SO i guess the ECU is the problem!
So you swapped the injectors around and still have 17 bar on number 4 cylinder, yes?
Did you by any chance do the compression test on number 4 with the injector disconnected?
I still have a bit of a doubt that the ECU is the problem. Looking at a 4 cylinder ECU circuit, pairs of injectors are driven by a single output transistor but via individual resistors. Assuming a 6 cylinder ECU has three output stages, each one driving a pair of injectors via individual resistors I don't see how one injector and not two can be turned on all the time. One of the single resistors going open circuit would stop the associated injector working, not turn it on constantly.
If it is really the ECU the problem would have to be one of the six large output resistors or the associated wiring, a short circuit to 12V for instance.
Before spending money on an ECU it might be a good idea to do what oscar suggested with the test lamp. Try to organise some way of connecting a 12 V lamp across number 4 injector and see if it lights constantly or flashes, an instrument panel lamp would be ideal.
koan
i have found a spare parts car now. The only problem is how im gonna get it home, it runs but its not safe to drive due to old hoses and bad brakes. If i cant get this home in some way, i will try what you said koan!
I have found a way to get it home now! So hopefully i can go get it this saturday or something like that. So now i got the ECU and the injectors :D
Good stuff bulba 8) Sounds like you've got a busy weekend up ahead. I want to see that 450 flying by Monday 8)
As always, its a new bump in the road. Not so big one though. The car trailer was broken, some electrical faults and stuff. But it will be fixed until after christmas, and then the new car arrives, hopefully.
The other car is here, ive changed the ECU and the injectors, now it doesent mix fuel in the oil anymore =) But now there is a new problem ofcourse, it wont start at all, wont even ignite (dont know what its called in english). Any ideas guys?
Well try to change back the ECU. Then you can identify if the other cars ECU is foulty. Maybe some of the little copper contacts in the 24 pice contact harness got bent?? Another idea is that you have got some oxidation on the breaker contacts.
/Niclas
Changed the ECU back, still nothing. Checked the contacts, nothing bent or anything. WHere is the breaker contacts located?
In the side of the distributor.
Cleaned up the breaker contacts, didnt work either. =/
Quote from: 13B on 22 January 2009, 05:10 PM
In the side of the distributor.
I was talking abaut the breaker contact for the ignition. It's located under the distrubutor cap (the red/orange cap).
Clean the contact points with a very fine sand paper and blow away all dust. A little grain of sand is enough for making it not start.
If you don't have any spark now disconect the ignition points an measure with an electrical tester that it opens and closes.
You can also check the opening distance of the breakers, it should be set by a dwell angle meter but if you start with 0,3mm it will run.
/Niclas
But i have spark, and its really good. Forgot to write that, sorry.
Nutz once wrote this, it's fantastic.
(On mine the temp sensor was connecte to pin #11 (instead of #13) so I guess there are different wiring diagrams.)
Have you tested the wiring?
Main relay;
1)There should be 12 volts at pin # 24 of the ECU.
2)If not,check for 12 volts at pin # 24 of the relay.
3)If 12 volts is not present at the relay but it clicks,replace with a new relay.
4)If there is 12 volts at pin # 24 of the relay,repair
# 24 wire between relay and ECU.
5)If the relay does not click,inspect the wire from the main relay pin # 45 to ground.
6)If the ground is good and 12 volts at relay pin # 38
when the engine is cranked,replace the main relay.
Trigger points;
1)With the engine not running and ECU harness disconnected from the ECU,check the resistance between
ECU harness 12 and 21,then from 12 to 22.One should show a low resistance and the other should show an open circuit.
2)Rotate the engine 360 degrees and check the resistance.They should have an opposite reading now.
3)If not,perform the same test at the trigger points themselves.This will tell you if it a component or wiring fault.
Temperature sensor 1
1)With the engine not running and the ECU harness
disconnected from the ECU,connect an ohmmeter between
ECU harness pin # 1 and 13.At an ambient temperature
the reading should be 200 ohms.
2)If the resistance is well above 200 ohms,check resistance at the sensor itself to determine if it is
a component or wiring fault.
3)Check resistance of all the terminals to chassis ground.There should always be an open circuit.
Temperature sensor 2
1)With the engine not running and the ECU harness
disconnected from the ECU,check the resistance between harness terminal 23 and ground.The resistance should be 2000 ohms at ambient temperature.
2)If the engine is near operating temperature,the resistance should be below 1000 ohms.
Throttle switch
1)Test the throttle switch with the key on,engine off.
2)Slowly open the throttle,and as it opens the injectors should alternately click.You should hear
20 evenly spaced clicks.
3)If this is not met,place a 0.016 in.(0.4mm)feeler
gauge between the throttle stop and throttle stop screw.Connect a voltmeter to terminal 17 of the throttle switch.The voltmeter should show voltage while the ignition key is in the on position.Remove the feeler gauge and the voltmeter should show no voltage now.
4)If this fails,loosen the screws and rotate the switch until it meets these requirements.
5)If they can not be met and voltage is always present no matter where you position,replace the throttle switch.
6)If the voltmeter reads no voltage,ensure voltage is
being supplied to the switch.If so,replace the throttle switch.
7)If no clicks are heard while performing test 1 and 2,check wire numbers 20,17,14 and 9 for continuity end
for end from the ECU to throttle switch.
Pressure sensor
1)With the engine not running and the ECU harness
disconnected from ECU,check the resistance from ECU
harness terminal # 7 to 15.Should be 90 ohms and then check the resistance between # 8 and 10.Should be
350 ohms.If this is not met,test the sensor itself.
2)on occasion,the sensor resistance will check out,but will not hold vacumm.Using a hand held vacumm pump perform this test again (step #1)
Injector circuit
1)With the engine not running and the ECU harness
disconnected from ECU,check resistance of ECU harness
pins # 3,4,5,and 6.All should have less than 25 ohms.
2)If the resistance is greatly higher or lower than
25 ohms,test the injector itself.
3)If the injectors pass,repair the wiring harness.
Ok i will check some of that stuff. The problem must be that the engine doesent get any fuel at all, because the spark is perfect and everything. When you turn the engine around it smells fuel, so i was thinking maybe a leak? But nothing under the car or anything. im gonna try and change the fuel pump. I accidently broke one of the "bolts" where you connect the wire, and just put it back and put a nut over it. THe pump builds up pressure, but i was thinking maybe its so poorly connected it doesent pump fuel?
I think the fuel pump either works or not. You should hear it pump for a second when you turn the ignition on.
/Niclas
Okey, it works then. Im gonna change the distributor this saturday or something and see if that helps ^^
It's quite easy to do the test above, just loosen the harness (the multi contact) on the ECU and follow the text. It takes about one hour.
/Niclas
Seems like one of the spare injectors was broken too. I tried another one and now it runs like a dream :D