Hi guys,

Thanks for the info so far. I've just read the new posts and I know what I'll be doing on my last day off. Gota love having old cars. ;)

Questions to all:
How common is it to have a delivery spring fail in an IP?
Will removing the access panel on the side of the IP at the delivery valves cause anything to become in jeopardy of falling out of place?


I consider my self a decent DYIer but no expert on IPs. However, I've successfully completed the R&R of the delivery springs, seals and washers my other 5 cylinder w201. I've been tinkering with MB diesels for about 5 years and anything mechanical since I was 13. So I'm confident enough to attack most jobs, but experienced enough to know when I've reached my limits. So what I'm saying is don't hold back anything! :)

I'm going to give up on this, I've spent a day trying cranking/charging with no change. And still no fuel at the front injector.
The glowplugs are relatively new and the weather has been nice and warm here so the GPs probably aren't an issue.

One last quick check. Open return line at injection pump.Does fuel come out when you crank engine? If so there is enough fuel present in the pump under at least a little pressure to supply the number one element.

The other manageable possibilities as I think you have a more modern injection pump than the 123s use. The delivery valve is fouled and not seating by something.Could be a section of broken spring for example. Or the elements seals have failed letting the elements pressure as it builds up escape internally.

Other than those two things I expect it is beyond the average person to repair in the pump. So a good used pump is in order in my opinion at that point. At least they are available..

Very rare. I've never heard of it.


No. You won't see the delivery valves though, those are in the fuel circuit. Removing the cover allows you visibilty to the external parts which are lubed by engine oil.


Don't worry about the front injector. The engine should start & run even with one dead cylinder.


You have checked for voltage at the GP's, right? And checked the fuse on the GP relay?


:blink:

All of the stuff I mentioned to check on the Fuel Injection Pump seldom happens (They represented things that I have seen happen to IPs when I used to work at a job where I rebuilt them that would result in no Fuel on one Element when everything else is OK).
I would check all of the normal issues first and leave the IP alone until you reach the point that you have eliminated everthing else.

The worst thing that can happen from removing the IP cover is that when you put it back on you might get a Oil leak there. This assumes that you did not do anything else but look inside.

It could be as barry said that for some reason you are simply not getting enough Fuel Supplied to the IP and it just happens #1 is higher than the rest and is not getting the Fuel Supply it needs.
No one has mentioned Fuel Supply Pressure from the Lift Pump Either.

Still Nothing
 

Okay, here's the latest update:

Still no change. :mad: I've cranked the engine/charged battery 20 times. Best was one time it sputtered for 4 seconds.

Could the delivery valve o-rings cause this problem w/o showing signs of fuel leakage? In my experience, when the DV seals are shot, the engine will be hard starting, but will still start.

@gsxr
You got me paranoid so I metered out the GPs and they seem okay. Can't reach one w/o removing intake; also I checked them at the relay. I think the GP relay is unique to this model; it certainly isn't the same as the non-turbo. YIKES, I hope not.

On this topic, could a bad temperature sensor or over-voltage relay or rpm sensor, etc. cause a no start. This turbo's IP is festooned with pods unlike my non-turbos.

@barry
Fuel is reaching the return.

My next step is to thoroughly clean the pump and surrounding area then remove the inspection cover. I won't get to it for a few days now as bad weather is scheduled for the next few days. I'm also considering replacing the delivery valve o-rings seals and springs as I did on my non-turbo. Made a big difference in performance.

I'll keep you posted on my progress.

THANKS AGAIN EVERYONE!

So it has gone from no Fuel on #1 to no Start at all?

Well it was running, then a lose of power event occurred, then no start. At that point, I checked to see if any fuel was getting to the injectors and discovered no fuel to #1. I have a feeling that fuel delivery to #1 was intermittent at idle before the car developed its current problem, because the engine would occasionally idle rough. The rough idle was occurring more frequently.

Now, I think I may have figured out what is wrong tonight. I will check out my theory and post what I find tomorrow. If I'm correct, THIS WILL BLOW YOUR MIND!

More tomorrow. Thanks all!!! :thumbsup::thumbsup:

When you say you 'metered out the glow plugs', you checked for +12v when the glow light is on, correct? And yes, I think the relay is unique to that model, although it may be the same as the 90-93 2.5T. Both should have factory afterglow function.

:scooter:

Sounds like the Lift-Pump to me....(yup, they do fail...)

Is the lift-pump delivering any pressure and any quantity...?

--Should be at least 7psi, but more like 10-15psi....

If the number 1 IP outlet/barrel/plunger were completely stuffed, it would still run on the other 4.
--It would obviously have a huge miss, but would start and run 'Reasonably' easily....

The main pump components, of elements, del. valves etc are pretty reliable, but can be damaged over time by use of Undried Veg-oil or poorly made BioDiesel that still contains moisture (Water)

Nah, Still points to Lift-pump from the description of fault IMHO....

Fixed and I Still Can't Believe It!
 

They say that you can tell how smart someone is by how much they agree with you. You, Alastair, are obviously of great intelligence! ;) This was where I was headed next. Had to be the lift pump! Right!?? The IP failing like this just didn't seem likely! Well here's what happened:

I just could not accept that the IP had failed so suddenly, so I started revisiting the more common possibilities. To help out, my brother, who fancies himself to be a super genius, stopped by Friday night to check out the problem. He, however, has no experience with MB diesels so I was more annoyed than thankful (at first anyway), as I had to explain everything to him, .... but his lack of knowledge turned out to be a blessing as you will see. Because of his lack of experience, he had me explain to him the fuel circuit and while I was describing the system we noticed something very odd.......the long and short of the story is that the previous owner's mechanic ( a very reputable shop here in SF Bay Area) made a major mistake. The PO recently had the cylinder head replaced, and on re-assembly the shop made a big mistake (see pictures below.)

I can't believe it would run at all, let alone fairly normally for a few months with this set up! And I can't believe I missed this when I was attempting to diagnose the problem. Just goes to show that you can't go into a job with any preconceived notions about the problem.

This is why I hate buying high mileage vehicles!!!! Too many people have monkeyed with too many parts.

So anyway, I installed them correctly, cranked it over and with a HUGE cloud of black smoke, it started right up and runs fine so far. I'll post if anything else happens as a result of this screwup.

I wonder what kind of damage this mistake could do? Luckily, it was only driven sparingly!

Well, THANKS FOR ALL THE HELP FROM EVERYONE. :beerchug: Once again this blog has proven to be the best source of information! I do greatly appreciate everyone taking the time to help out with my problem.:beerchug:

-John

So all your problems were due to reversed fuel lines ??

Id sure be replacing the filter.

Yeah, it would seems so. What I can't figure out is, why it stopped running though, maybe the lift in the lift pump has lost some power, or maybe the screen in the tank is a little more clogged. Who knows. But hopefully, whatever it is, fails while I am near home like this did.

It sure has more power off the bottom now!

Also, I am noticing some "nailing" at idle when the engine is not above 80 degrees.

Glad you got it sorted! (And, Thanks for the compliment;) )

It Had to be summit in the fuel-supply as I saw it, and basically as the filter had been changed, and all the usual checked, to me--it pointed to the Lift-Pump...

Man-Made faults are Always the worst to sort out, as you're assuming the layout is fitted correctly, and jump to the wrong conclusions because of this...:D

Well spotted!:)

that was the next thing I was going to suggest, check to make sure the fuel lines going to the filter are on properly,,, good job

unfrieking believable! I have no diesel experience but I'm a competent mechanic, I never would have thought it would run like that

one of my favorite quotes is "Just because you found it like that doesnt mean it's supposed to be like that"