Hanging Idle
Hanging Idle So this thing is running really good now and I've got it tuned pretty close. I've had PCM for Less send me a computer and made a second tweek at it. It idles normal and runs smooth but after about an hour of driving the idle will start to pick up and aim for 2000 when driving. It will settle back to normal 1000 after the car comes to a complete stop. What is causing this and how do I fix this?
I have been tweeking with the idle adj screw on the tb which seemed to help for a bit the first time but the problem returned. I'm not sure if it's requiring more or less air at idle. Before the second tune, it was really bad and as soon as the car warmed up, it would do it. Any clues?
I have been tweeking with the idle adj screw on the tb which seemed to help for a bit the first time but the problem returned. I'm not sure if it's requiring more or less air at idle. Before the second tune, it was really bad and as soon as the car warmed up, it would do it. Any clues?
Originally Posted by Dixit
Throttle Cracker values probably too high.
Dixit
Dixit
Alright, I'll have to talk to brian at pcmforless. I drove it all last night and it was fine and then started to hang again. I gave the throttle screw a quarter turn and it has been better but every once in a while will hang around 1500 or so but at the same time, it will drop around 600 if I push the clutch in. Drivability is fine and seems to run great but the idling issues are getting annoyting. I also am getting the SES light from one code that says mass air circuit low. It has been on a while but when I restart the pcm, it stays off until the next time I turn the key on and start.
Teching In
Joined: Jan 2006
Posts: 11
Likes: 0
Originally Posted by hissin'98
Alright, I'll have to talk to brian at pcmforless. I drove it all last night and it was fine and then started to hang again. I gave the throttle screw a quarter turn and it has been better but every once in a while will hang around 1500 or so but at the same time, it will drop around 600 if I push the clutch in. Drivability is fine and seems to run great but the idling issues are getting annoyting. I also am getting the SES light from one code that says mass air circuit low. It has been on a while but when I restart the pcm, it stays off until the next time I turn the key on and start.
Trending Topics
not always the throttle cracker
if you tb set screw is open too far it may see tps > 0% and you may have the iac steps already at 0 so it nolonger controls the idle. get the idle airflow right, then make sure the cracker doesnt have crazy high values (like the stock 2000 table). make sure at idle your iac steps arent any lower than 30 or so when fully warm.
if you tb set screw is open too far it may see tps > 0% and you may have the iac steps already at 0 so it nolonger controls the idle. get the idle airflow right, then make sure the cracker doesnt have crazy high values (like the stock 2000 table). make sure at idle your iac steps arent any lower than 30 or so when fully warm.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Originally Posted by 98A4LS1
To dial in the base RAF, do you typically need to increase the values after cam install?
The cam will decide whether the values need to increased or decreased. I haven't seen a cam install yet that didn't require these values to be changed. Every cam I've seen so far required decreasing these values.
it also depends a lot on the rpm you are idling at, should mention that as well. 2 guys with the same cam could have totally different tables depending on how they like their idle
