Stuck on high idle plus underboost

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PRINCETON_JAKE

New member
I have a fully built 2006 cummins I had efi live done on. Wow it's anazing! By far the best mod to date, but at the same time I enharited a problem...

The truck is stuck at a 1,000 rpm idle, it does NOT kick off when I touch the brake or when it warms up, it is also trying to pull in gear. One thing we found is the flash scan lists 2 different temp readings, one matches the dash and changes with engine warm up, the other is stuck at -40 degrees.

Today, roughly 600 miles sense tuning, i stopped at a gas station for fuel and when I fired it up the check engine light came on the second it fired. At that point it was in limp mode so I limped to oriellys and scanned it, there was a P0266 "under boost" code. I cleared it and everything was fine the rest of the way home. Its had a boost fooler on it for the last 5+ years and the limiters disabled on top of that....
 
I believe there are two temp sensors. One for the gauge and one for the ecm. My guess is the bade my temp sensor is causing the high idle issue. The code and limp mode is probably from the boost fooler that went bad.
 
I can't find a second sensor anywhere, not even in diagrams. That's my thought.

If the boost fooler (resistor) was bad the code wouldn't clear. Plus the efi has that circuit disabled
 
The high idle problem sounds like a temp sensor. For ambient air temp the only one is the sensor in the grill by the drivers headlight. They are cheap. There is also the intake air temp sensor that could be the culprit as well. Id scan it while disconnecting one at a time to figure out which one it is.

You shouldn't need a boost fooler with EFILive. That can be all done with the tune. If its connected to the wastegate connector then thats a wastegate fooler, which is just a resistor to load the circuit. Have your tuner look at Internal Flash/Turbo/Boost Pressure, Too Low Thresholds if that is stock Id lower it by 5.5 PSI. That seems to work for me with the low boost issue.
 
arinkuddy said:
The high idle problem sounds like a temp sensor. For ambient air temp the only one is the sensor in the grill by the drivers headlight. They are cheap. There is also the intake air temp sensor that could be the culprit as well. Id scan it while disconnecting one at a time to figure out which one it is.

You shouldn't need a boost fooler with EFILive. That can be all done with the tune. If its connected to the wastegate connector then thats a wastegate fooler, which is just a resistor to load the circuit. Have your tuner look at Internal Flash/Turbo/Boost Pressure, Too Low Thresholds if that is stock Id lower it by 5.5 PSI. That seems to work for me with the low boost issue.
Click to expand...


All the sensors are reading correct other then one of the 2 coolant temps shown on the computer, and I can only find the one by the thermostat that Sean's to only control the guage.

Thanks for the info on the boost
 
We pulled the efi out and it was no longer idling at 1,000rpm. We tried multiple things and different computer softwares no matter what it's stuck on 1,000rpm when we put any efi tune in it.

Any help?

Hoping to figure that out so i can figure out a surge I have around 1,400rpm
 
Without seeing the tune it's all a guessing game. The tune is causing it or your truck is not agreeing with the operating system used.

Sent from my E6782 using Tapatalk
 
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