New problem with my 450

[Niclas]

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

[Bulba]

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?

[oscar]

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

[Bulba]

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 =)

[Bulba]

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

[Niclas]

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

[Bulba]

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.

[oscar]

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.

[Bulba]

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.

[koan]

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

[Bulba]

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.

[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.

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

[John Hubertz]

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...

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.

[oscar]

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.

[Bulba]

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