Harmonic balancer,turbo, injectors?????

[625fireman]

I have posted on this prob before. I have done a few things to help but it still surges at idle. (not all the time but enough to be really !@(*#^! annoying. I think I have it down to three things now but still dont know for sure.

1) Can a "bad" harmonic balancer make the engine surge at idle but run down the road fine???

2) Can a "bad" turbo cause the engine to surge at idle but run down the road fine ????

3) Or could it be the injectors???

OBTW new in IP helped but didnt completely solve the problem.:smile5:
new filter didnt help:mad2:

 

[matuva]

Is your CTS (cooling temp sensor) fine ?
What happens if you disconnect it or wiggle its harness ?

 

[Chevylover]

Is your CTS (cooling temp sensor) fine ?
What happens if you disconnect it or wiggle its harness ?

Thought the same, but also thought about the OPS (oil pressure sender).
Perhaps at idle oil pressure is very low or the the sender thinks this and doesn't deliver enough Volts to the lift pump ? Also a small possebility could be air bubbles in a fuel line.


Cu,
Sven

 

[625fireman]

Thanks but nope on both. replaced the sensor three weeks ago. And just checked the volts at the pump the all fine. Now I have more problems anyway.

 

[Non Typical]

1- Air getting into the fuel lines somewhere.
2- Injectors getting flaky. How many miles on them?
I doubt your turbo or balancer has anything to do with it. It's not giving up any codes?

 

[mfgguru]

I know your truck is obdI, but I checked for stock ecm updates for my truck and one of the corrections in the new program was idle surge. Just a thought, maybe a reflash is in order.

 

[625fireman]

Well here is the story. The truck started life as an automatic trans after 2 rebuilds and no one would touch it I priced new 4L80e. Without a core and one "built" to handle plowing and towing it was $2800. So for $2000 I put in a NV4500, and all was fine so I thought. Then the surging at idle started. I called Heath after suggested to from here. He was very helpfull. he gave me a few things to do. One was the 2000 rpm test to see if IP was good. IP failed test. So I bought a rebuild from Pensecola Diesel. Put it in and surging went away for the most part. Just occasionly it would do it not everytime I hit a red light......Till yesterday. After 1.5 weeks with the new pump the truck starts acting the same way it did with old pump. So I did the 2000 rpm test with the new pump. It FAILED. So now my big question is.....
Does the ECM dictate which trans should be in the truck or is it in the chip??? I did not change the chip or ECM when I changed to the NV 4500. It does have soft codes( no SES light) they are all trans related: 73,81,82,83.

OBTW the truck has 89,000 miles.

Thanks guys. I love my truck but dammit I am getting tired of this SH*T!!!!!

 

[guybb3]

Am I wrong or are the 81,82,83 cylinder imbalance codes?

 

[NVW]

Am I wrong or are the 81,82,83 cylinder imbalance codes?

91 through 98 are the imbalance codes.

Leo

 

[Matt Bachand]

I have posted on this prob before. I have done a few things to help but it still surges at idle. (not all the time but enough to be really !@(*#^! annoying. I think I have it down to three things now but still dont know for sure.

1) Can a "bad" harmonic balancer make the engine surge at idle but run down the road fine???

2) Can a "bad" turbo cause the engine to surge at idle but run down the road fine ????

3) Or could it be the injectors???

OBTW new in IP helped but didnt completely solve the problem.:smile5:
new filter didnt help:mad2:

Sounds like you have forum paranoia worrying about harmonic balancer and or turbo I worry about my HB everytime i hear a noise in the engine bay...

I don't think it would cause surging idle. If fuel pressure checks ok, the computer does all the fuel negotiating, so unsteady surging would have to have something to do with the computer fuel injection area, I would think.

As always check/clean all grounds and fuses. Make sure PMD grounded to IP. Batteries charged and good, and alternator putting out 14 or so volts.

 

[guybb3]

91 through 98 are the imbalance codes.

Leo

Thanks for clearing that up, NVW!:thumbsup: