XD2S: can't get it right

[SilverSupraT]

First, I'll start with the back story. Bought the car and it would always start but just "ok". Would rumble to a start and smoke mostly gray, some blue-ish, smoke for several minutes. After it warmed up it ran fine, although it was REALLY gutless with black smoke on hard acceleration (this turned out to be a completely disintegrated boot from the turbo to the intake). The car had been parked in a dry climate for over 5 years and after running would leak EVERYWHERE and nearly every liquid; so I decided to do a freshening up rebuild.

The car has an original 190,000 miles on it (XD2S engine, manual transmission) The rebuild consisted mostly of just replacing all of the gaskets and seals while checking everything along the way. Rod and main bearings were in great shape and on the tight end of the original tolerance. Timing chain was marked when removed and put back together by the book as well as rematching the original removal marks. Injectors were pop tested and operating perfectly. The injector pump hasn't been professionally tested but crude tests appeared to have it firing on time, just before TDC. Did all of the valve clearances just to be sure (interference engines scare me!). Compression test showed 360 PSI on cylinders 1-3 and 410 PSI on number 4 (this is from front to back - I know it opposite of how it's labelled). No noticeable wear or glazing on the cylinder walls so I didn't bother replacing the rings or honing the cylinders. Also, checked the entire block and head for crack; none detected.

Now for the problem(s): had a heck of a time priming the fuel but finally got it to run....with the exact same smoke condition as before. At this time I hadn't pulled the injectors to be tested. After I had pulled them to be tested, I haven't been able to get it to run at all. It's smoking, but not firing.

Are my compression numbers good or bad? Any tips on timing setup?

CLIFFS: Car ran but smoked on cold start. Rebuilt engine but got same results. Having trouble getting it to fire now.

I've already double and triple checked everything so any suggestions are welcome and I will happily redo anything with the hope of fixing this thing! I really want this to be my DD.

Thanks in advance!

[Bean]

Have you tested the glow plugs? Is it on manual control or factory relay set up? Cold start up issues sound like typical bad glow plugs or crap glow plug relay.

Common fix is a manually controlled solenoid, new wires direct to each glow plug (not in series), and new Bosch glow plugs. Pump timing, and ensuring the injector nozzles have good patterns is also important as the pop pressures.

Not sure on cylinder compression - but I thought over 300 was pretty good.

Rabin

[JunktionFET]

Make sure no air is getting into the fuel system. The stock Purflux filter canister and primer bulb are prime suspects, [no?] pun intended. The rubber diaphragm in the primer is replaceable. I've also seen pinholes form in the steel fuel feed line under the car.

As Rabin suggests, verify the glow plugs work. Just one dead one can make starting a difficult and smokey experience.

Does the injection pump leak fuel in any way?

If the injectors are original, I guarantee they need to be rebuilt--new nozzle and recalibrate the opening pressure.

Setting the injection timing properly is a hairy procedure where you measure crank angle by dropping an exhaust valve and measuring it with a dial indicator, and set the start of injection (also a dial indicator ordeal on the injection pump) to spec. So with that said, there is "another way":

Though I'm never a fan of duct tape and bailing wire solutions, the quick and dirty way to set injection timing is to listen to the engine.

1. First mark the top of the injection pump mounting flange and engine timing cover somehow. This will give you the original position of the pump in case the adjustment procedure goes pear shaped.

2. With the engine running and at operating temperature, loosen the pump and rotate it away from the engine block. This retards the timing. You'll hear the engine become "eerily" quiet. Very gradually turn the pump toward the block (advance) until the diesel "rap" becomes distinct. That is more or less where you want the timing. Of course, error on the side of "retard", as over advanced timing will kill the engine in a few thousand miles.

3. With any luck you'll end up with the pump at or slightly more "advanced" that the original mark you made.

It is important that you first verify your injectors are all in good shape and balanced. As injectors wear, the nozzles erode and the opening pressures change. You can't reliably set injection timing by ear if you have injectors that are all opening at different pressures and atomizing fuel differently. This is very very important!

[SilverSupraT]

Thank you both for the input!

I checked the glow plugs, there was one bad plug. So, my only doubt with that being the WHOLE fix is that it would start before and now I can't get it to start anymore. I'm going to just replace them all for good measure (not that expensive, surprisingly). The controller appears to be working, getting 12V to the bus as well as at each plug.

The injectors were pop tested and the spray pattern was great and consistant across all of them. Held pressure too, not leaking over time. I thought that might be the case because of the cold start smoke...

My filter has the leak as you described so it is temporarily bypassed (still being ran through a filter, however) so that I don't have to suspect that as part of the problem. The pump doesn't leak anywhere, not even around the pulley shaft. Once it is primed it's good to go, no air builds up. It definately puts out enough pressure to each injector to open them up.

I'm going to start with the new plugs. Then the crude timing proceedure, even though I've kind of done that. Then, if things still don't work, I'll the the all-out timing process so that I can rule that out as well.

Thanks again! Will update once I get things done.

[SilverSupraT]

I think that I got it figured out!!!

I bled the fuel, again.... lol. Then put in the new glow plugs and it started up immediately! I was super excited. I was in a hurry to get somewhere so I just shut it down. Later, I got back to it and wanted to double check the pump timing. It try to sputter and start but wouldn't again .

I went through a battery of priming processes and was POSITIVE that my IP and lines were completely purged of air. Luckily, I hooked them up from front to back... I put a jumper wire to my starter, waited for the lines to start spewing out fuel, then tighted the lines onto the injector. After hooking up the first 2 injectors it started running, then the 3rd and it ran better, then the last one and it ran fine.

Slowly, it started running worse, and worse, and finally died. I unhooked the last line at the injector, cranked it again and then it ran. Then hooked it up and it eventually died again. I put a clear line onto the return to watch the fuel. When only the first 3 were hooked up there were no bubbles but once I hooked up the 4th injector it got a TON of bubbles. Allas! I was getting pressure back through the 4th injector (no1 cyclinder)!!!

I am going to get it repaired or a replacement and then I will update with a definite fix. Thank you all again for the input that helped to keep me going and figure this thing out!