Rebuilt IP - Runs but not hardly...looking for suggestions

[rameye]

Well the saga continues...

I finally got he truck to start after massive bleeding of injectors...the only way it would start was if I mashed the pedal...then if I'm very careful I can remove my foot and she'll kinda idle...

Moved the pump to get my best numbers on the tech 1 close to 3.5 degrees base timing still runs awful...wants to die...puffing smoke (blue/grey) like I've never seen before. Moved the pump all over to try to get her to run better..

Called Gomers (rebuilder) checked with them they suggested the usual, grounds etc. Changed over to my spare PMd..no better. Removed manifold, re-checked firing order (only removed four lines to change pump) firing order is spot on.

Plenty of fuel pressure, codes initialially indicated bad cylinder balance in all cylinders probably due to crummy running, got those all settled down.

Running it with the manifold off, loud popping from center ports on heads...I figure this is normal with the manifold off...no popping with the manifold on and in place. All grounds re-checked all connectors rechecked, shook and moved wires and connectors while running no changes.

Ok so here it is...smoke screen idle, very rough (smoothes out with throttle) wants to stall, wont start unless you mash the pedal.

Questions;

1) Is it all possible to have installed the IP incorrectly, that is the alignment into the gear???

2) Is it possible that I may have bounced or jumped time by rotating the engine by hand with the IP gear somewhat loose??

3) should I have the pump re-benched???

Thank-you for your responses...it's coming to the point where I woulld like to put a bullet in the truck at this point. 3 weeks ago it ran terrific but had the pump re-done due to a starting to fail fuel solenoid....jeez!!

Going nuts trying to crack this case.

[Mainous]

How did you time the pump gear. It sounds as though you have a timing issue. Did you rotate the cam gear up to align with pump gear?

[rameye]

the pump has a pin that fits into the gear...took it out..had it re-done...put it back in the same alignment..

Never had the timing gear/chain apart if thats what you mean..

[Mainous]

Did you have the front cover off or did you go through the oil filler hole? Is it possible that you inadvertantly rotated the pump gear? With the pump out it kind of just floats in it's housing.

[rameye]

thru the oil filler hole as reccomended...

Is it possible for the gear to have jumped??

[gmctd]

Center ports are exhaust ports for the EGR system, so popping is normal with intake off.

Do you have a Tech1?

[rameye]

thanks gmctd..

I figured the it was normal..they seem to pop with each fire of the cylinder..not too worried.

Ever hear of the pump gear moving a tooth or two when its unbolted from the pump?? From what I've read it's not possible.

How can you tell if it did move? (without taking off the cover would be nifty)

Really puzzling this situation...16 degrees doesnt really help matters..

As an update I'm looking for air entering the system...seems most likely.. so far no air has been found exiting the pump..thats as far as I made it in the cold after work.

To answer your question...Yes I have a Tech 1, and I have set the base timing to 3.5 and was able to do an offset learn and locked it in @ -.50

Did not make it run any better, will still die if I let off the pedal, smoking like crazy unburned fuel. Moving the pump 1/8 inch from my center mark gives me no improvement..same symptoms..

Any help, suggestions, things that need to be ruled out, are always appreciated.

Thanks

[gmctd]

Excellent on the Tech1 - what is your

Des\Act idle rpm

ECT

IAT

Des\Act timing

injector pulse width

fuel rate

CPS pulses missed

Post those numbers, then

Pull the OS connector, run the engine for about 15mins to clear the bubbles outta the injector pipes - it will be running in 'limp mode' program, and should smooth out until\as bubbles are passed.

'Limp mode' does not correct for cylinder balance at idle, lets the Inj Pump do it's hydraulic thing without interference.

Run the same parameters again, post them for further............

[rameye]

Here are the numbers off the Tech 1..

With the optical sensor in place

Desired Actual
Idle 638 679
ECT 172
IAT manifold off -38
Timing 8.3 8.4
pulse width 1.65
fuel rate 14 mm
no pulse misses
offset -.79

With sensor disconnected

Idle 750 750
Temp 185
IAT -38
Fuel Rate 18mm
Timing 13.7 8.4
Pulse width 1.62
TDC offset -.79


Engine still smoking with unburnt fuel...very gray and stinky......not antifreeze!

Ran somewhat smoother with optical sensor unplugged, could even put it in gear!...

Still runs like crap however....
Clear tubing for IP exit reveals no bubbles what so ever
Fuel pressure is 7psi with vehicle running
Plan on having drivers side injectors (1 y/o) popped and pattern checked)
this week.....will probably have pump re-benched to make sure nothing went wrong in transit..

I'm holding off inspecting the chain and gearset as a last resort..

your thoughts...

[gmctd]

AHA! ! ....... if desired is 13 and actual is 8, would seem to indicate trouble with the Timing Stepper Motor.

Cold engines need advance for ease of starting and to ignite and burn the fuel in a cold cylinder - PCM is demanding advance, but cannot get it.

Have a look at the TSM - lower front side on passenger-side of Inj Pump - should be fully retracted - up - for full advance.

Normally should be moving up and down slightly around center position as engine is idling at operating temps

[rameye]

would it matter that I have not really got my base timing exactly to where I want it to be?? Usually I base it at 3.5..

I will check that stepper motor out..

I'll check back in a couple of days..

Thanks for the help

[gmctd]

Yes, but timing will not set if the TSM is stuck or not functional.

Observe TSM position with the ECT connected vs disconnected.

If it is fully retracted, rotate the IP to the driver's side by 2mm.

If fully extended - rotate to passenger-side by 2mm.

Crank the engine to start, and observe TSM position at idle, noting smoke and idle quality.

[Robyn]

After reading through these posts I would be suspect of the IP.
Normally even after a dry start the engines will smooth out in a very short time and run fine.

Very likely the IP has some issues that rebuilder either missed or whatever?????

[rameye]

Thanks for the reply Robyn,,,I cant help but think that also..the engine ran 100% no issues, before I took the pump off for maintainence and sent it out for a new fuel solenoid.

Before I send it back for a do-over I'm trying to rule out all other causes.

I have faith in US Diesel as a service center..want to give them the benefit of the doubt..

Thanks again...

stepper motor results to follow.

[rameye]

GMCTD I'll check that out this week...caught up in the Xmas rush..

I appreciate the help

[rameye]

After a process of elimination here was the cause of all my strife and horror. I found 4 injectors (these we a year old) which were dribbling/no pattern. I feel/know this haapened when I bent my injection lines outta the way in order to slide the pump out. I wanted to to do a quick pump change and did not want to disassemble the dark side of the engine.

Well my shortcut turned into a serious ordeal...many questions many possible solutions...this was the ultimate brain tease for me.

I am sure that when I bent my old lines outta the way I broke off crap from the inside of the line which traveled down to the injector and screwed up but good!

That led to new injectors/replaced some glow plugs/timing chain because I dropped a washer down the front cover and sheared the camshaft key, new water pump (hey why not I'm here anyway), new injector lines, and all sorts of odds and ends.

Learn from my mistake: If you try to shortcut (because you dont have a garage and it was gettin cold fast) you have a very good chance of your little quick fix turning into a big expensive PITA!!

However on the good side I learned a whole bunch about my truck, and got to talk to some nice folks, and contributed to economy..

PS thanks to Morepower for his guide books, very helpful where GM was vague.