injector pump problems?
 

Hello,
I have 1982 300D, and it doesn't start. heres the story:
I got it in fall of 2006, and it was running quite well. i recently set it up to run on veggie oil. after installing the second fuel system, i tried to start it (on diesel) and it wouldn't start. i found an air leak in the lines, fixed it, and it started and ran fine. a few days later (i still haven't run any veggie thru it yet) the lube oil supply line to the IP popped off while i was driving :eek:. i caught it very fast, after driving for only about 5 min. but during that time it ran very low on oil. i had a more experienced mechanic check it out, and there was no damage to the engine, but the turbo whining quite a bit. I purchased a used turbo, and installed it.
when i started the car after installing the turbo it seemed to be running a bit rough. 10min later it stalled, and hasn't ran for more than 10sec. since. it cranks, fires, runs really rough for a few seconds, then dies. i checked fuel line s for air an found a few small bubbles before the IP. i checked the connections, and bled the whole system. its still didn't start.
I removed the injector lines where they come out of the IP and cranked it over. spurts port closest to the front of the car had no fuel coming out...

I'm on the verge of dishing out for a rebuilt IP, but i really wouldn't like to. anybody have any ideas?

Thanks in advance,
Ethan

xceth,

My opinion is U have a lack of fuel getting to the IP. Someplace there might be a air leak in one of the input lines.

Take the output line off the IP and while pumping the primer pump, determine if fuel is coming out of the IP. [I]f no fuel comes out, find out why.

Before U buy a rebuilt IP, Take your IP to a Bosh or Injection pump shop and have it tested. If there is something simple wrong with ur IP, it will cost much less to fix than buying a rebuilt IP.

P E H

Almost all the fuel lines on the supply side of the IP are clear, and there are no bubbles in them.

when i pump the primer pump there is no (or very little) fuel coming out of the return from the IP. It just kind of builds up pressure somewhere. but it has run fine before with the fuel system the way it is now.

i can't see how it can stop working after putting the new turbo in... thats whats got me stumped. it makes me think it has to be air... but theres no air visible in the lines up the the IP

xceth,

If there is no fuel coming out of the IP, that is definitely your problem. I don't know how U set up the new fuel system, but some how the fuel is by passing the the IP.

P E H

there is no way fro fuel to bypass the IP. the fuel system setup i am using is a standard setup for veggie oil conversions, and has worked for many other people running WVO. keep mind, the car has run like this before.

:1blank:

this is what my fuel system looks like:
http://i14.photobucket.com/albums/a3...asecarfuel.jpg

excth,

I don't see the fuel connections to the Veggie oil tank so I don't quite understand the fuel diagram.

One thing wrong with the diagram is that the fuel outlet of the IP should be at the top of the IP so any air is bled out.

If no fuel is coming out of the IP, nothing is going in. There is a resistance in the IP outlet valve to build fuel pressure in the IP. Maybe the pressure of the outlet valve is higher than the pump priming the IP so no fuel is going into the IP.

I still think ur problem is air in the IP or no fuel going into the IP.

xzeth
 

would you post what you mean by running very low on oil? how much was added to get it back to full?also did the low oil cause any heating issues?
larry perkins

What happens if you were to try to "bottle feed" the IP clean diesel as if you were using purge? Should be simple enough to check.
I thinking air in the line somewhere. Few MB IP failures.

when i say i ran low on oil the little oil supply line to the injector pump popped off. we literally pumped the oil out of the engine. i noticed a slight difference in sound, and saw the oil pressure was down. i pulled over, and there was a oil splattered all over the engine, and it smelt like a hot engine. we put about 6 quarts in it to get it full. (i believe it has a 7-7.5 quart capacity). it drove home fine other than a slight whine in higher RPMs from the turbo.

i have heard of the pressure valve in the banjo fitting where the return leaves the output of the IP. is there a way to check this? if its not getting enough pressure to open it does that mean my lift pump may be bad?

Thanks,
Ethan

i will try bottle feeding it tomorrow.

one other thing to consider:
i tried bleeding the system at the injectors(where the injector line attaches to the injector) and i get what seems like plenty of fuel surging out of all but one of them. one of them has nothing.

You may have more than IP issues. How's the oil pressure now? Any smoke when it runs for the short period?
Might have to check the compression next.

The big question... how far is the drive home? At 6 qts low you may have to find a replacement engine.

it was driven with low oil for no more than five min. we stopped, added 6 quarts, then drove home.

it was smoking a bit more after the incident, but it was at high RPMs, and was in correspondence with the whining turbo,so i assume it was a symptom of the turbo bearing being worn out, and it wasn't getting enough air.

now it has very little smoke (when it manages to run long enough), and it's white smoke.

it seems like there is air in the injector pump. is there any other way to get it out other than bleeding at the injectors?

:eek: :eek: :eek: :eek:

At a quick glance, I see about 40 potential failure points, not counting the french fries and chicken bones. Of course, I may have missed a few.