6.5td injection pump

[alderson95]

i had to replace the timming chain back gasket. after i put it all together no leak. but when i went to start it it almost strarts then just spins over. i have checked all fuses and glowplugs. is it posible the i dont have the injection pump set just right. the truck is a 1996 gmc k3500 6.5td 4l80e. any help would be greatly aprechated.

[sctrailrider]

Yes it is possible, I am not sure how you do it, but you need to do a tdc relearn on the pump, I think you need a scan tool for that on a electric pump..

Search here for tdc relearn or set timing and see what comes up...

[Robyn]

Did you remove the IP completely ???? injector lines and such??

Missy

[alderson95]

i have a obd 2 scanner. the only codes that i had got on the truck where low fule sole secut code or somthing like that. and the other one was turbo valve thing. im not getting any codes from the injection pump. i did complettly remove the pump when i changed the gasket. i set it back dot to dot.

[DmaxMaverick]

If it ran fine before, had no codes, and you put the pump back where you found it, you shouldn't need to do any relearn or tweaking with it. Sounds like it's airlocked. Verify fuel supply, and check all your electrical connections and grounds. Also shoot some WD40 through the wastegate solenoid, while you're in there.

[alderson95]

The injection pump isn't getting airlocked. I just checked. But I did notice 2 marks on the timing chain cover. Right where the pump bolts up. There are 2 marks thar look like timing marks. I'm going to atempt to turn the injection pump slightly and see if that helps.

[alderson95]

I never completly pulled the injection pump basicly just pushed it back. But I did turn the motor to put the pump back dot to dot. Is it posible the the injection pump is a 180° out.

[DmaxMaverick]

The pump can't be 180° out, but the chain/sprocket can be. If you think it's possible that it happened, get a look at it.

[alderson95]

What i ment was, could the pump be on the exhaust stroke and not the intake. i dint udnderstand what you mean by the gear sproket could be 180out. when i put it on it only went on one way.

[DmaxMaverick]

Then no. Your pump timing will be correct, unless something is broken. The pump will engage the gear at only one index location, and same with the crank and cam sprockets and pump gear. If all you did was replace the chain, lined up the dots, and put the pump back where it was before, the problem is elsewhere.

[alderson95]

ok then now that that idea has been eleminated. i am going to try to turn the pump a bit. i noticed that if you were looking at the motor from the front the pump was turned all the way to the right i will try to pull it back dead center. i have made sure its not airlocked. when i got to strat it it acts like its right there, but still doesnt want to start. so i figure the pump is getting the fule to the piston slightly to late. so hopfully turningit a bit will fix the problem. thanx guys

[DmaxMaverick]

If it started, ran, then died, the problem isn't the timing. Still sounds like air in the system. How did you confirm it's not the problem?

[JohnC]

If it started, ran, then died,...

Any chance it sheared the key?

[DmaxMaverick]

Any chance it sheared the key?

Of course, it's possible. However, they rarely ever shear all by themselves. If a key is sheared, something else is likely wrong. I think it's still early to consider that.

[alderson95]

Ok I got the motor to start. All I did was readjust the injection pump. I set the pump but when I went to start it hi had to hold the pedle down to keep it running. So I'm going to turn it some more to so if I an find a sweet spot. And how I checked the airlocl problem was I undo one line to.a injector and crank the motor over to see if fule came out.

[greatwhite]

Your getting it running with nothing more than turning the pump indicates it's out of time.

Install your IP "straight up" first.

IOW, the shut off solenoid should be straight up and down.

If it starts, you can set TDCO on an OBDII truck with a key on/key off procedure.

The truck will relearn the new position of the IP.

Best thing to do is get a scanner that can at least read TDCO as the truck will run with a setting pretty far out of timing (-2.02 to +2,02 IIRC, but memory is foggy these days).

With a scanner that reads TDCO you can set it in the optimal range.

You can buy a program called "car code" to read and set TDCO on an obdII truck. I have one, cost around 60 bucks. It's not user friendly at all. But you can find step by step procedures to read and set TDCO on teh web forums with this program on a 6.5 truck.

The thing about turning it until you find the "sweet spot" is that the PCM has the old TDCO value in memory. If the truck ever initiates a TDCO relearn, you're most likely going to be sitting by the side of the road. It will relearn the new position, see it's not what it wants and then codes will be set, it'll run like crap or it will just plain stop.

The same thing happened to me once. The PO had done some engine work and when I bought it it ran fine. Somewhere along the line, the truck decided to initiate TDCO relearn and the value was waaay off. The truck ran like crap until I got it home, re-timed it (turn pump and run time set) and initiated a proper TDCO relearn procedure and then adjusted it within TDCO OEM specs.....

[alderson95]

One thing it seems that no matter what degree I have the pump at it barlly wants to start then it dies right after that. I checked my fule lines to the fule bowl. The fule came to it good. But when I turned the little t-handle drain on the colant cross over no fule came out. I had the key on every thing and I got nothing. I am going to get a new fule fillter tomorrow. It's cheap and simple to do. One other thing I tried to start it with the pmd unpluged the truck didn't throw any codes. Needless to say the engine didn't want to start at all. So I pluged the pmd backup and it did the same thing run very briefly then die.also I do have a code being thrown its code p0238 boost sensor I kbow why tho. I have no lines running to the switch cuz they got dry rotted and broke. I just found it odd that the pmd wouldn't throw any codes.

[greatwhite]

One thing it seems that no matter what degree I have the pump at it barlly wants to start then it dies right after that. I checked my fule lines to the fule bowl. The fule came to it good. But when I turned the little t-handle drain on the colant cross over no fule came out. I had the key on every thing and I got nothing. I am going to get a new fule fillter tomorrow. It's cheap and simple to do. One other thing I tried to start it with the pmd unpluged the truck didn't throw any codes. Needless to say the engine didn't want to start at all. So I pluged the pmd backup and it did the same thing run very briefly then die.also I do have a code being thrown its code p0238 boost sensor I kbow why tho. I have no lines running to the switch cuz they got dry rotted and broke. I just found it odd that the pmd wouldn't throw any codes.

Ah, filter makes sense then.

The T handle is the drain for the Filter manager. Fuel in to the manager but none out sure says filter to me....

[alderson95]

Ya makeing an ameture move I new the fillter was dirty but I chose to ignore it so ill get that fixed and tell yall more

[alderson95]

One last thing ypu said I jad to make the truck relearn the timing. I didn't underrstand how you said to do it.

[DmaxMaverick]

If it starts, then dies, has fuel, then doesn't, means fuel supply (pump operation). Even the most plugged filter will still have fuel flow at the drain (T-valve at the water crossover), as it's on the "dirty" side. Sounds like you are getting fuel during the "start" cycle, but none during the "run" cycle. Could be ignition switch, relay, or harness/connector issue.

[racer55]

The ecm learns and records the IP's position relative to the crankshaft,like setting a distributor on a gasser.

With electronic IP's anytime a crank sensor,PMD resistor aor IP adjustment is made the TDCO(top dead center offset) must be relearned.

A quality scanner like a tech1,2 or GMTD ScanTech(94,95),carcode or auto enginuity or tech 2 for 96+ can initiate the relearn procedure.

Lesser quality scanners can however display the TDCO value and with the use of the KOKO procedure the relearn can b initiated manually on 96+:
KOKO procedure info:
http://www.thedieselpageforums.com/tdpforum/showthread.php?t=30686&highlight=koko

[alderson95]

well i was out working on the truck today and i was trying to start the truck when i herd somthing spilling on the ground. i get under to see what it is and its leaking diesel. i go up to to the motor. come to find out the fule delivery line was hocked to the return line. i had asked my wife replace the fule lines in the back of the motor while i had the intake off. the lines where dry rotted. she replaced the lines but hooked them to the wrong place. i geus the return lines would fill with diesel and make the motor run for a spilt second. so i swaped the lines back and tried to start the truck. it started on the first try. i cant belive that i would mis that. iv been at this game for a while. but things like that make me feel like an ameture. but the truck runs great i cant thank you guys enuf for all yalls help. thanx

[jdd75]

alderson95
Enthusiast

Sure hope the "Little Darling" dosn't
read TDP.LOL!