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Need help! In a pickle in Nome, Alaska

dbrannon79 said:
My thought was while the IP was out doesn't that gear just float there sitting on the cam gear? during the install could the gear be lifted in the effort to get it on the IP and accidentally ended up one tooth off from where it was?
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Yes it just floats there. Not sure there is enough room for it to jump off.
 
Shatmepants said:
I'm wondering if I should pull the water pump and cover to verify the drive gear position. This truck was running perfectly before it simply would not start, so nothing would have happened to the drive gear prior to these guys installing two new (rebuilt) pumps. But given how many hands have been on this thing in the past year, I'd like to cross the drive gear scenario off my list of possibilities if possible before installing the third new pump (which we found and picked up from Anchorage yesterday).
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It's not physically possible to jump the IP gear out of time as there is NOT enough clearance in the chain drive housing to allow the gears to un-mesh. I have tried it.

However, the timing chain will stretch out to very very sloppy from the normal shock IP loads and I have seen the sprockets wear down the crankshaft key. Hold over bad cost cutting design decision from the Oldsmobile Diesel "We didn't learn Nuthin" disaster. Manual calls for 6 month timing adjustments on the DB2 mechanical IP's due to known chain stretch.

I would change the IP without touching it at this time. If this pump also has trouble then figure on replacing the chain while you are in there. Cloyes is a good brand as the "engine tech krap brand" I got one time had a sprocket machined off center.
 
Man, what a long couple of days. I won't leave you guys hanging, but I'm way too tired tonight to tell the story. We don't have it running yet, but I'm hopeful that tomorrow we will.

Thanks again for all the help and recommendations. I'll report back asap.
 
It turns out it was a couple of different issues. I don't know what caused what, but the OS in the "rebuilt" IP from Heath was bad and we had a section of burned wires in the wiring harness (buried in the harness). I have no idea what caused the burnt wiring. There were no blown fuses and it was obvious by the corrosion on the bar wire that it had been that way for a very long time.

We installed a new pump (thank you Advance Diesel in Anchorage for the new pump) and I repaired the harness and we finally got the thing started on Friday. I tuned it the best I could, but it still has a light stumble at idle and just off idle, but going down the road it runs nice and smooth with good power. I wish I had time to get it 100% correct, but I had to catch a plane early Saturday morning.

Concerning the TDC offset reset and setting the IP timing, I simply couldn't get things right. I went through the reset procedure a few times, but I simply could not get the value down below 1.9. Obviously, that is way off the -.25 to -.75 mark. So, I tried setting the timing (as it says to do in the manual), but I couldn't get the actual pump timing (as read on the scanner) below 9ish. Again, way off the 3.5 mark. I did get the IP timed to the point that the scanner would read 3.5, but the motor ran terribly. So I did the TDC offset procedure again, then the IP timing read 11ish without touching the IP timing.

Having run out of time, I had to leave it the way it is, but I'd love to know your thoughts on why I can't get the TDC offset and the IP timing within the correct values. My best guess is that it's a timing chain issue, as a few of you mentioned above.
 
Shatmepants said:
It turns out it was a couple of different issues. I don't know what caused what, but the OS in the "rebuilt" IP from Heath was bad and we had a section of burned wires in the wiring harness (buried in the harness). I have no idea what caused the burnt wiring. There were no blown fuses and it was obvious by the corrosion on the bar wire that it had been that way for a very long time.

We installed a new pump (thank you Advance Diesel in Anchorage for the new pump) and I repaired the harness and we finally got the thing started on Friday. I tuned it the best I could, but it still has a light stumble at idle and just off idle, but going down the road it runs nice and smooth with good power. I wish I had time to get it 100% correct, but I had to catch a plane early Saturday morning.

Concerning the TDC offset reset and setting the IP timing, I simply couldn't get things right. I went through the reset procedure a few times, but I simply could not get the value down below 1.9. Obviously, that is way off the -.25 to -.75 mark. So, I tried setting the timing (as it says to do in the manual), but I couldn't get the actual pump timing (as read on the scanner) below 9ish. Again, way off the 3.5 mark. I did get the IP timed to the point that the scanner would read 3.5, but the motor ran terribly. So I did the TDC offset procedure again, then the IP timing read 11ish without touching the IP timing.

Having run out of time, I had to leave it the way it is, but I'd love to know your thoughts on why I can't get the TDC offset and the IP timing within the correct values. My best guess is that it's a timing chain issue, as a few of you mentioned above.
Click to expand...
When you got it to 3.5, that is when you do the TDC offset, regardless of how it ran. -1.94 is the lowest you can go on TDC Offset. Most say that reading provides optimal performance, but the engine will run considerably louder. My ‘94 is set at -1.94.
 
IIRC, on the OBD-II, physical mounting of the IP is not as critical for timing. It does need to get close-enough though. Specifically, the computer is going to control actual timing depending on what the logic calls-for at the moment. Physical orientation does make a difference as it allows for a range of advance and the computer figures this out. Moving the IP will change the range of advance that the computer gets to use.
 
That’s great to hear that the truck is running smooth enough to drive. Great catch on the harness and the successful repairs there.

FWIW, Physical orientation of the IP is essential to get the base timing to 3.5.

You do the Time Set function on the scanner, the truck stumbles like a drunk for a second and then smooths out.
Check timing and if it isn’t 3.5, adjust as directed.
Once you move the pump to get the timing to read 3.5 then you lock it down. You don’t do another Time Set.
This is when you perform the TDCO set procedures.

A new IP wiring harness can be had from Quadstar if the occasion or angst calls for it.
 
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