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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 

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

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!