Diesel pump

HelmuthChevy

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Hello guys.
I need advice about a problem with a chevy 6.5 turbo diesel 1994.
I full rebuilt my engine and, when I start engine have some trouble to start cause Injection Timing Stepper Motor doesn't work (was broken when I check it).
After I replace it, engine, starting without problems, BUT I got new errors (code 34, 91,92,93,94,95,96,97,98).
My mechanic, 2 years ago, warn me optical sensor start to create problems and I wondering if this sensor can create error 9x to the cylinder (cylinder balance fault) or, maybe, is to check diesel pump position (*******).
Thanks in advance everyone can answer.
 

Supercharged111

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I'm not very well versed in the 6.5 stuff, and I'm not sure if you have definitions for those codes, but here is what I found with a quick Google search.


34 is injection timing stepper motor fault and the rest are cylinders nder balance faults. It sounds like the pump wasn't the fix after all, is the stepper motor part of that assembly or separate?
 

smdk2500

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. It sounds like the pump wasn't the fix after all, is the stepper motor part of that assembly or separate?
The stepper is part of the pump.
Hello guys.
I need advice about a problem with a chevy 6.5 turbo diesel 1994.
I full rebuilt my engine and, when I start engine have some trouble to start cause Injection Timing Stepper Motor doesn't work (was broken when I check it).
After I replace it, engine, starting without problems, BUT I got new errors (code 34, 91,92,93,94,95,96,97,98).
My mechanic, 2 years ago, warn me optical sensor start to create problems and I wondering if this sensor can create error 9x to the cylinder (cylinder balance fault) or, maybe, is to check diesel pump position (*******).
Thanks in advance everyone can answer.
Did you replace the whole injection pump or just the stepper motor? If you replaced the whole pump did you verify that the timing is correct? Also if you replaced the whole pump there are some places out there that have been known to sell junk remans so it could be still a pump problem.
 

HelmuthChevy

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The stepper is part of the pump.

Did you replace the whole injection pump or just the stepper motor? If you replaced the whole pump did you verify that the timing is correct? Also if you replaced the whole pump there are some places out there that have been known to sell junk remans so it could be still a pump problem.
I replace only step motor on my pump and engine start without problems.
I put back pump after rebuilt engine (new pistons, new cranckshaft and camshaft bearings, new oil pump and rebuilt top heads and new diesel plug and relay).
On beginning engine starting difficulty because I discover step motor was stuck (check it and internal was full of rust and rubber gasket broket), after change it engine starting great.

Now problem are from error 34 (optical sensor maybe fault) and error 91 to 98.

What I can say more? Yes, there is something. On exhaust there is to much smoke for my opinion (new exhaust straight pipe 3" with only one short silencer).
 

HelmuthChevy

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I'm not very well versed in the 6.5 stuff, and I'm not sure if you have definitions for those codes, but here is what I found with a quick Google search.


34 is injection timing stepper motor fault and the rest are cylinders nder balance faults. It sounds like the pump wasn't the fix after all, is the stepper motor part of that assembly or separate?
Thank you but I know this part. I need to know more about "cylinder balance fault"
 

HelmuthChevy

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The stepper is part of the pump.

Did you replace the whole injection pump or just the stepper motor? If you replaced the whole pump did you verify that the timing is correct? Also if you replaced the whole pump there are some places out there that have been known to sell junk remans so it could be still a pump problem.
You confirm maybe problem of wrong timing pump position?
I used the old references from before my engine was rebuilt (I also painted the engine, I can't see any other "marks"). Maybe I need to move the pump forward or backward from its current position? Anticipate or delay?
 

smdk2500

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Do you have the filter still plugged into the optical sensor? I have read that having this still installed can cause weird problems. It is a small black box that covers the wires. Unplug it and throw it in the trash then plug the harness into the optical sensor. The smoke could be from the rebuilding process. What color is the smoke? Did you replace the injectors in the rebuild or have them pop tested? A leaky injector can cause smokey starts. Reading on another forum about your code 34 it could be a pump timing problem. The stepper is trying to change the timing but cannot because it is at its limit of movement to adjust timing. I would check the timing of the pump and see how far off it is. As for your 91-98 codes I am not sure about. I will have to do some reading on that.
 

HelmuthChevy

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Do you have the filter still plugged into the optical sensor? I have read that having this still installed can cause weird problems. It is a small black box that covers the wires. Unplug it and throw it in the trash then plug the harness into the optical sensor. The smoke could be from the rebuilding process. What color is the smoke? Did you replace the injectors in the rebuild or have them pop tested? A leaky injector can cause smokey starts. Reading on another forum about your code 34 it could be a pump timing problem. The stepper is trying to change the timing but cannot because it is at its limit of movement to adjust timing. I would check the timing of the pump and see how far off it is. As for your 91-98 codes I am not sure about. I will have to do some reading on that.
~ Yes, stil in position filter on cable. Next week I try to remove it, erase errors, and check if still exists those errors.
Good idea test it.
~ still original iniectors, they was in good shape, no problems from them before.
~ l had a ground problem (on dash I saw a lot of error). Fix this problem 3 errors are disappear but I will check ground for pump cable (I had to modify pmd cable ground because was to short).
Probably there is a mix of weird problems create this situation.

IIn the end, what I have to do are:
Remove cable filter ;
Modify timming pump position;
Increase ground connections.
Maybe, after this, I can save some money and wait to change optical sensor.
At the moment engine starting good in a couple of seconds.

Ps
Errors from 91 to 98 is called "cylinder balance fault" but stil am not sure what it means.
 

HelmuthChevy

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Do you have the filter still plugged into the optical sensor? I have read that having this still installed can cause weird problems. It is a small black box that covers the wires. Unplug it and throw it in the trash then plug the harness into the optical sensor. The smoke could be from the rebuilding process. What color is the smoke? Did you replace the injectors in the rebuild or have them pop tested? A leaky injector can cause smokey starts. Reading on another forum about your code 34 it could be a pump timing problem. The stepper is trying to change the timing but cannot because it is at its limit of movement to adjust timing. I would check the timing of the pump and see how far off it is. As for your 91-98 codes I am not sure about. I will have to do some reading on that.
I made some tests.
~ try to remove filter on cable and nothing change.
~ I try to adjust pump position and much less smoke on exhaust but still error 34 and 91 to 98.
~ during those test I discover turbo leaking a lot of oil on the intake.
I think this can make a difference
 
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