erratic throttle response 6.5TD

[stapleton]

I have a 94 6.5td. A new problem started today. When I am driving the engine speed sometimes stays high even after a release the gas peddle. A small movement in the peddle cause a strong acceleration. I checked for codes and none are showing. The truck runs fine on cruise at highway speeds. The problem seems to be there most of the time but sometimes the throttle will respond correctly while other times it revs very high or just stays at the rpm it was before I release the peddle. Restarting the engine clears the problem for a short time. The only change I made the recently was to add a remote mounted d-tech pmd. I read the article on throttle position sensor. The service throttle light is one when I turn key to on but not when engine is running. I assume the light is on as a test. Hopefully someone can help.

[Kennedy]

The APP module while not infallible is seldom the issue. Id try a super dose of lubricity additive and see what that does. We have seen the pump delivery stick and cause this. Lubricity might not help and is not really a long term fix, but worth a shot to see if it can help.

[stapleton]

The APP module while not infallible is seldom the issue. Id try a super dose of lubricity additive and see what that does. We have seen the pump delivery stick and cause this. Lubricity might not help and is not really a long term fix, but worth a shot to see if it can help.

After several months of just parking the truck I finally took it to a local mechanic. He drove the truck several time but it acted nomal every time. From my description of the problem he thinks he problem is in the injection pump but wanted to see the problem repeat before replacing the pump considering the cost. Is the long term fix you mentioned mean replacing the injector pump? The delivey pump you mentioned is the one in the injector pump?

[quickv6]

I had a truck do the same thing. Act like the pedal was sticking so to speak. Also It would only rev to about 1500. The problem was the injection pump.

[Yukon6.2]

Hi
Befor you replace the injection pump,try another PMD/FSD.I had a new Dtech i installed last year that came with eratic throttle issues.I spent some time chasing problems that were in the Dtech,Changed the PMD/FSD with a good used one and it went away.The Dtech was replaced on warrenty.
Check the easyest stuff first, seeing how you just added the Dtech it may have some issues.
Good Luck
Thomas

[Kennedy]

After several months of just parking the truck I finally took it to a local mechanic. He drove the truck several time but it acted nomal every time. From my description of the problem he thinks he problem is in the injection pump but wanted to see the problem repeat before replacing the pump considering the cost. Is the long term fix you mentioned mean replacing the injector pump? The delivey pump you mentioned is the one in the injector pump?


I guess I would try the PMD first like Yukon stated.

I've never warmed up to the Dtech/Flight units. Hard to trust a product with NO verifiable testing and made by a company that formerly sold reman DS4 pumps with USED PMD's :rolleyes:

[JohnC]

My '95 did that a few times after I put a #9 resistor in. Mostly kept going for a moment after I let off the throttle. Put the #4 back and never had an issue again????

[stapleton]

Thanks for all the comments. I had installed the pmd the day or so before the problem occurred. Only drove around the block to see if it worked. I had driven for 2 hours on a summer day before the problem started. Maybe the mechanic is not seeing the problem now since it is winter/cold outside here and it is a heat related problem in the pmd. I think I will reconnect the old pmd on the pump and drive the truck to see if problem returns. If the problem is the actual pump then I assume the problem will return in a short period of time.