LOw idle and chasing throatle coming to a stop help!
03-11-2011, 01:11 PM
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LOw idle and chasing throatle coming to a stop help! I have a 99 trans am ws6 auto... And heres whats happening... In park, it idles at 700 rpms.. but thats not the problem... when im in drive it idles at 400 to 500 rpms at a stop. which is low low... Also when coming to a stop the car rpms will be searching .... it will drop all the way to 300 rpms and then jump back up to 900 rpms and back 400.. sometimes it will even die completely.. SOmeone told me it most likely the IAC sensor... so i bought one... still does the exact same thing.... If anyone has any ideas let me know .. thanks any help or ideas.. thanks again let me know
03-12-2011, 06:47 AM
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Yup, pretty much. Not sure you need to turn the key on for 30 sec, maybe 5-10 secs. Give it a shot and see if it works.
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03-12-2011, 04:15 PM
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I have been messing with this for a while now... lol ... i bought a brand new pvc hose from gm... i replaced all the small lines as well... and i even went as far as putting new intake gaskets on... its driving me crazy lol
03-12-2011, 10:47 PM
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Yeah thats the retail peice value. i get gm discount and some.. so it wasnt too bad.. but they dont have very many of them left.. i had it ship from a distant dealership... i about **** myself when i seen the retail value on the pcv set up lol.. i was like 120 for plastic lines and a pcv valve lol..... it goes valve cover to valve cover and up to the throttle body.
03-13-2011, 08:25 PM
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Ok so i reseted the tps.. well it not dieing now.. and its not falling on its face coming to a stop... but the idle rpms is still low... like 500to 600 rpms.... I noticed there is a set screw in the trottle body ... do u think i could adjust the throttle body to adjust its idle rpms? or should i not mess with it? also, what is the idea rpms in drive and in park? shouldnt it be more like 700 to 900 rpms. one last thing what are common reasons for a low idle.. i heard bad grounds can be a cause...
03-15-2011, 07:16 PM
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I'm having the same type of problem. Mine goes just fine it just idles
Right around 450 500. I've checked for vacuum leaks but I still can't
Find anything
Right around 450 500. I've checked for vacuum leaks but I still can't
Find anything
03-15-2011, 10:29 PM
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I've just kind of learned to live with it but it would be nice
If it was any easy fix. I think I've read somewhere not to
Mess with that screw but you're always welcome to try haha
If it was any easy fix. I think I've read somewhere not to
Mess with that screw but you're always welcome to try haha
03-16-2011, 12:19 PM
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I may be having some Race style LT's and ORY installed soon which will require it to be tuned. Hopefully I can get him to try and figure it out. He's a mechanic that specializes in F body's so he should know what the problem is.
03-16-2011, 08:39 PM
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Lid and Magnaflow cat-back. It did this when I got it when it was completely stock so I didn't do it haha.
The previous owner said it was a rear o2 sensor but when I hooked up the OBDII scanner it was the circuit and the fuse was blown. I had a check engine light with mine though.
The MAF fuse kept blowing, throwing a code and when I reset the TPS is quit doing it. I also reset the TPS and it helped it not die and the SES light quit coming on. I got a new MAF sensor and even tried using MAF cleaner and it didn't help. I changed the plugs and wires thinking it just wasn't firing right but that didn't changed it. Changed the AIR sensors when I did the plugs and wires. Also tried STP fuel injector cleaner when I got it and just recently tried chevron techron thinking it could be the injectors but that didn't really help. I still get 20 mpg combined and I don't baby it to say the least.
I don't think a rear o2 sensor would cause rough idle but a bad ground on the fronts might...It's pretty much the same problem, we have just done different things to try and fix it. I drove it about two and a half hours on the interstate and it actually searched for idle more than before. Like it made it worse. I hate sitting at stop lights now because it just idles rough and feels like its going to die. I've been trying to find the right idle rpm for these cars but haven't had any luck. I know something is wrong but you and I are the only ones to have this problem it seems like. I really wish someone would step up with this and help us out diagnosing. If not, I will try to remember to ask when I get my Lt's installed in a couple weeks to check the wires on the o2's and offer some advice. I'm just talking here lol. going through EVERYTHING i can think of.
The previous owner said it was a rear o2 sensor but when I hooked up the OBDII scanner it was the circuit and the fuse was blown. I had a check engine light with mine though.
The MAF fuse kept blowing, throwing a code and when I reset the TPS is quit doing it. I also reset the TPS and it helped it not die and the SES light quit coming on. I got a new MAF sensor and even tried using MAF cleaner and it didn't help. I changed the plugs and wires thinking it just wasn't firing right but that didn't changed it. Changed the AIR sensors when I did the plugs and wires. Also tried STP fuel injector cleaner when I got it and just recently tried chevron techron thinking it could be the injectors but that didn't really help. I still get 20 mpg combined and I don't baby it to say the least.
I don't think a rear o2 sensor would cause rough idle but a bad ground on the fronts might...It's pretty much the same problem, we have just done different things to try and fix it. I drove it about two and a half hours on the interstate and it actually searched for idle more than before. Like it made it worse. I hate sitting at stop lights now because it just idles rough and feels like its going to die. I've been trying to find the right idle rpm for these cars but haven't had any luck. I know something is wrong but you and I are the only ones to have this problem it seems like. I really wish someone would step up with this and help us out diagnosing. If not, I will try to remember to ask when I get my Lt's installed in a couple weeks to check the wires on the o2's and offer some advice. I'm just talking here lol. going through EVERYTHING i can think of.
Last edited by 85CamaroZ28; 03-16-2011 at 09:02 PM.
03-16-2011, 10:38 PM
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I just did a search on bad TPS sensors, some people are saying after replacing it they see 8-900 rpms. I guess that's about right? Maybe us resetting it just got it back to a decent running point.
Does yours shift kinda hard when you go from park to drive or park to reverse?
I'm not going to be able to work on mine for the next few days but hopefully I can try this out soon. If you happen to get to it lmk
Does yours shift kinda hard when you go from park to drive or park to reverse?
I'm not going to be able to work on mine for the next few days but hopefully I can try this out soon. If you happen to get to it lmk