Car never reaches closed loop....
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From: Cleburne Tx
Car never reaches closed loop.... Im not very educated in "tuning" at all but i figured this is the appropriate sections to post in concerning this question.
I just bought a 98 Camaro and the previous owner installed a cam and all supporting valve train components, and has ran nitrous through the car, ported throttle body pretty much full bolt ons and then some and he had the car tuned and when he had the car tuned the guy who tuned it told him it would be better with a new model pcm... so he also had the pcm repined and then tuned.
My question is when i start the car it seems to do the complete opposite of what im use to in h.i.c. motors. Its surges at idle for a good 30 seconds to a minute then finally seems to level out and my scan gauge seems to tell me it never goes into closed loop, it always says open loop...
So im puzzled as to if its "tuned" that way or because of my longtubes and where the o2s are located the o2s never do there job or what. Ive emailed the guy who tuned it but no reply back.
Thanks for the help.
I just bought a 98 Camaro and the previous owner installed a cam and all supporting valve train components, and has ran nitrous through the car, ported throttle body pretty much full bolt ons and then some and he had the car tuned and when he had the car tuned the guy who tuned it told him it would be better with a new model pcm... so he also had the pcm repined and then tuned.
My question is when i start the car it seems to do the complete opposite of what im use to in h.i.c. motors. Its surges at idle for a good 30 seconds to a minute then finally seems to level out and my scan gauge seems to tell me it never goes into closed loop, it always says open loop...
So im puzzled as to if its "tuned" that way or because of my longtubes and where the o2s are located the o2s never do there job or what. Ive emailed the guy who tuned it but no reply back.
Thanks for the help.
Thread Starter
Registered User
Joined: Dec 2014
Posts: 4
Likes: 0
From: Cleburne Tx
Thread Starter
Registered User
Joined: Dec 2014
Posts: 4
Likes: 0
From: Cleburne Tx
Yes car warms up and around 100-120 the car starts idling like it should. "like it went into closed loop but doesnt..."
One way to save yourself some work in getting it to
idle right after a cam & headers, is to force open loop
full time. This eliminates the problems of false trimming
from cold pipes full of shot-through intake air. But it's
not righteous - only expedient.
Multiple things happen about 140F. Closed loop fueling
is one. Closed loop idle RPM control is another. Which
one you are observing, is a question. They have separate
(but initially equal) threshold settings in the tune.
idle right after a cam & headers, is to force open loop
full time. This eliminates the problems of false trimming
from cold pipes full of shot-through intake air. But it's
not righteous - only expedient.
Multiple things happen about 140F. Closed loop fueling
is one. Closed loop idle RPM control is another. Which
one you are observing, is a question. They have separate
(but initially equal) threshold settings in the tune.
