Yes unexpected expenses are painful. I usually try to farm out as little of our needs as possible because of the unpredictable nature of their costs when doing so.

In addition you almost have to keep a critical eye on things then as well. I do not feel there is a paranoia factor involved because I still seem to get caught up occassionally in what is today.

So my approach always leaves somewhat of a constant backlog of things to get caught up with. That is a real understatement at times. Also for too many reasons to list the approach I use is certainly not for everyone.

The re-calibrated new pump is back in and the it idles fine. When its warm at speed it acts like it is running on 5 cylinders. When checked by cracking each line there is no change in the idle at the #5 cylinder. The Compression test was excellent but this was done when the engine was cold. I requested that they keep the car one more day, get it up to operating temperature and then do a compression test on cylinder #5.

At this point I don't know what else to do apart from start preparing the #17 head that I have in the event that the #5 has a crack in the head there.

There is no oil in the radiator and no coolant in the oil.

Ideas??

Is it safe to drive it like this till I prepare the new head? Or could there be further damage if I do drive it?

Thanks
Mark

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91 300GD SWB with transplanted 87 OM603 turbo motor

The engine was running fine until the runaway with the old pump? Installation of the new pump indicated the number five element had definate issues. Perhaps from long term storage. It was sent out for repair.

Now you have a problem of some sort on the number five cylinder after the repair. It seems to me you should have a talk to those that repaired the pump.

There is of course coincidence but there is also a chance the repair of the number five element was not totally successful. As the fuel gets hotter in the injection pump perhaps it is going or passing by in the element bore a little too much.

One test would be to run an injector on the end of the hard line with it not mounted in the head. Is there any output from that injector with the car warmed up?

You could run the engine up to temperature. Then install an injector on the hard line and start yout test. Since there is no differance when you loosen off the number five injetor feed nut after the engine is hot there may be no output from that injector.

For example if the bore of the number five injection pump element had some corrosion it might just seize up high in the bore once the elements piston heated up. There is a chance that after getting warmed up the delivery valve is staying open I guess as another even more unlikely possibility.

If so there would be no usable fuel out of the injector I would suspect. I just think it would be too coincidental if the engine had not exhibited this behaviour before your semi runaway you experienced.

I could see this pump testing well on a test stand in a service facility as it is obviously working well before your car gets warmed up. The internals of the pump heat up as well remember with running. I personally would not suspect a problem in that number five cylinder at this time that is not injection pump involved. Your hot compression check tomorrrow will be fine on that number five cylinder tomorrow I suspect.

I assume that the valve clearances have been checked in the last fifteen thousand miles. Or you are pretty certain that the number five cylinders valve clearance is there to some extent. In my books this is a long shot even as my common sense says it should not have a rapid onset as you have experienced.

Barry
Thanks for the input. This shop that did the recalibration is a Bosch certified that the dealership has used since the 70's so I would hope what they did was correct.

I had the same thought as you that the pump element element when hot was not performing but: When they cracked the #5 cylinder line the fuel came out of the line as it should.

The injectors have been swapped around to see if there is a bad one in the mix but the issue stays with #5

Do you think that just driving it may loosen this up?

Any possibility that the #5 prechamber is clogged?

Mark

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91 300GD SWB with transplanted 87 OM603 turbo motor

The #5 cylinder hot compression test tomorrow is more for my piece of mind and fact gathering.

Mark

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91 300GD SWB with transplanted 87 OM603 turbo motor

Peace of mind does help any of us. It concievably might loosen up by use if it were a sticking element piston when hot. Depends what is exactly wrong in there.

Open hard line test is not that conclusive.

Only if the injector is not producing a spray when the engine and injection pump is hot. I could see any injection pump shop missing something like this. In many ways it is better than facing a head job at least.

If the cost is gettting out of control. You could get a pump lock and pull the pump and take it back to the shop if you prove this is still an injection pump issue first.

All the injectors were bench tested as well and the spray was as it should be.

I do have a pump lock but I think I may just run it for awhile and see what happens.

For a motor that was running well before it just seems odd that it now exhibits this issue after the pump install.

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91 300GD SWB with transplanted 87 OM603 turbo motor

Well it should not hurt anything. Make sure to notify the shop that fixed the pump. Just so they cannot later claim it is a new fault or whatever.

I was just sittting here thinking that if the problem does not go away. Try the engine on vegatable oil. If the engine remains firing on the number five when hot. The element bore is bad.

If not probably the element piston is sticking. I was also thinking about some aditive that might help the piston and bore if it is sticking but cannot think of anything.

Using the engine and pump may yet kind of lap it free with some time if it is a little rusty.

Thanks I will pick it up later today.

Mark

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91 300GD SWB with transplanted 87 OM603 turbo motor

Picking the vehicle up tomorrow (Monday). They said that the #5 cylinder hot compression test showed insignificant change in the compression. For me that indicates that the head is OK.

So i am just going to drive it and see what happens.

Thanks for all the responses.
Mark

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91 300GD SWB with transplanted 87 OM603 turbo motor

Sorry this has turned out to be so painful. It will be interesting to see what if anything occurs with you trying it for awhile.

Thanks Barry
We will see what happens.

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91 300GD SWB with transplanted 87 OM603 turbo motor

I went to pick up my G today. Drove it up the street and it ran horrible!

So I turned around and went back to the dealership. On the way back I began running all the test scenarios that I did when Hunter was helping me troubleshoot over the phone.

One scenario that kept coming to mind was when I had the crossover pipe removed and the turbo covered with a rag. The engine fired up but once again began to race. So I shut it off immediately. I expressed what happened to Hunter and said that I could not find the T-shirt rag that I was using to cover the turbo. I did find a similar rag on the floor on the other side of the garage so I just thought that it was the one.

Well after todays miserable maiden voyage I went over that again with the techs and said what say we pull the intake manifold and see if by some chance I have a t-shirt in there.

Low and Behold the T-shirt was in the manifold draped over #5 and #6 intakes. How bizarre is that!!

I will once again be going to pick it up tomorrow. You just have to laugh at such a bizarre series of events.

1. Injection pump goes bad.
2. While trouble shooting lets let the engine ingest a t-shirt to further complicate things.

Hopefully all will be good tomorrow.

Mark

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91 300GD SWB with transplanted 87 OM603 turbo motor

Photo of the pipe.
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Thanks to everyone for the advise and well wishes.

Mark
Thanks Hunter

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91 300GD SWB with transplanted 87 OM603 turbo motor

Thank goodness it was simple.
The picture is impressive.

.

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