After I put the 60lb injectors, 2.8 pulley, NGK Step 2 plugs and a tune done by ItalianJoe, I been feeling my car with a bad idle, usually that bad idle that I am getting has to do with spark plugs or something like that. I took all four spark plugs out and checked them, they seem to be perfectly fine. It doesn't happen at all times, when the car is cold and I just turn it on, it runs perfectly. When it gets hot sometimes still runs good but let's say I been driving for a while, I start to feel it when I come to a stop. The RPM meter does not move up and down from 900, it just stays there but the car feels like if it was going on lower RPM's and coming back up. Also It happens when I rev my car to like 1500 RPMs, usually the meter goes a bit up and down there, and also u can hear my exhaust do little backfires like if it was failing. Joe has looked at it couple of times, but can't seem to figure out what it is. U guys got any ideas??? I am thinking on getting a video of it to see if that helps u guys maybe figure out what it is. I have also checked the intake for any holes or any escape of air, and I see none, and felt nothing coming out of there. Guys let me know if u have any idea what it can be.

Thanks.

 

Have you taken things apart and cleaned them? Have you checked for any vac leaks? Do you know if you are running off a maf tune or ve tune and do you know if they are dialed in. Joe does some great work from what I have heard. Some things you should look into are your fuel trims, you want them to be within +/- 5. With that being said, just simply do a log with Joe and see how the fuel trims are. If they are not within the standard then do a little more work.

If this is not tuning related in the least, I would recommend doing some general maintenance and cleaning. It's hard to say exactly what it is without a log/scan of the car, however this is something I do see a lot when tuning cars that have zzp's canned tune. No offense to zzp in any ways but I have tuned several of there cars that have had this issue, as will all canned tunes.

 

I have done some cleaning, for example the TB, twice since I did the changes, inside of the SC, the injectors are basically new, the spark plugs cleaned out. I am going to take off the Intake when I get the Heat Exchanger, and clean the filer and pipe. Anything else I should look forward to cleaning???

 

maybe you have a cylinder misfire. joe can check the codes in 2 mins or any auto store will do it for free

 

Im experiencing the same thing after my 60's and 2.7 install. My car runs fine when cold but when its warms up it idles wierd. I have tried everything. Tune, injectors, plugs, MAF cleaning and it has not resolved it. Your car goes into closed loop when it warms. When your in closed loop the O2 sensor controls fueling. When in open loop (Cold and WOT) mine runs fine. Check your O2 sensors. Im doing it next week. Any other ideas would be useful.

 

Mine does that with my current mods but it's because I'm tuned rich as ****.

 

60s have a rough idle and im having problems with my idle when i come to a stop, they either go too low(shutting the car off) or come close and bounce back up to like 900 or whatever normal idle is.

drives fine but its just coming to a complete stop, i had the car shut off on me like 4 times, but lately i just watch it and kick the gas a tad to keep her alive haha its sad
my tuner is gonna look at it again.
at cold start or any i believe it idles fine and the A/F is good and then it leans out and the car sounds like its cammed haha a lil misfires
since im not on the gas the A/F isnt reading anything, on throttle and at WOT it is fine
a guy at my work thought i was cammed, i told him rough idle play boy hahaha

 

Same here , 60's with zzp canned tune and it runs bad when warm but in a different way , sometimes when I stop at the lights my rpms will bounce up and down by 1000 rpm until i tap the gas , otherwise "almost" normal idle (up and down by maybe 75-100rpm)

 

60s do NOT have a bad idle, they just need to be properly tuned for guys.

 

Exact same symptoms as mine. Thats why I think its o2.

 

maybe


i wanted to say that your rims look super good, great flow haha

 

Thanks! The reason why I think that is because its only doing it in closed loop.

 

It's ur injector pulse with mine did it also u have to pin the 60's to .9ms other wise ull get injector missfire

 

Sorry for bringing back an old thread but this goes right into what is happening with my redline. Idle when warm is bad, my girlfriend who knows nothing about cars said it sounds funny. Idle gets reallyyyy bad when cruising in neutral, jumps from 500-2000. As soon as I stop it gets a little better, and rpms are constant but still rough. Got misfire code along with P0503 and P0102. What did you guys do to fix this?

 

next time post the frigging definition of the code you can find them here https://www.cobaltss.net/forums/prob...-merged-12015/

P0102 Mass Air Flow (MAF) Sensor Circuit Low Frequency -PCM
P0503 Vehicle Speed Sensor (VSS) Circuit Intermittent -PCM

its awesome that you searched but you cant get help if you only give half of it we cant pull the code definition of the top of our heads

check the fuses and then check connections and clean if need be and check the voltages on the wires to determine if you have a sensor or wiring problem and repair as required

 

Gm vehicles are known for bad grounds. First thing I do with any GM is to add extra ground wires from the body to engine and body to battery. If that don't fix it then I'd try opening up the throttle butterfly at idle position but that's a guess.

 

Ill do that next time, sorry.

MAF reads from 25-45 cfm, throttle without driver interaction opens from 16%-23%, and timing advance reads -2 to 10 degrees, all respectively from 500-2000 rpm.Cold/warm the car idles the same, therefore not 02. If I unplug the inlet pressure sensor, MAP, or MAF, there is very little difference in idle. Cleaned MAF already, vacuum is 20inHg during idle, so that's fine as well. TB is pretty clean, haven't cleaned it for a few months, but the idle was a little better back then too.

Recent work that has been done to the car is ZZP stage 3 tune with 2.9" and 60's, phenolic spacer, and I already had every other bolt on you could say, along with Bwoody mounts.

 

get the tune checked out and what is the afr

 

Cold start at idle was about 11.8. Warm idle varied because of the rpms bouncing, went from 12 - 17, after a little time it steadies and stays near 14 - 16. Now.. cruising idle (cold or warm) is a big problem. goes full lean to full rich when bouncing anywhere below 2000 rpm.

 

get the tune checked

 

I honestly don't think it is the tune, my car did this since I bought it stock but as bad. I have been researching problems like this and ran into someone saying the evap solenoid was bad. Coincidentally the evap is part of the intake's airflow that I overlooked. Is there a way to check this? I will try to unplug it and see if that works, perhaps from the TB and plug the hole. If that doesn't work, Im going to try an expensive tune up and buy some used parts from Mongo and replace the MAF, MAP, coils, 02, and maybe throttle body.

 

just plug the evap I don't even run it

 

Plug the port on the TB for the evap solenoid? After that, what do I do with the solenoid's hose? Lol I live in Ohio so I kind of still need it.. but the evap canister on my redline is behind the rear axle right? Ironically I used to hear 3 thumps come from the rear of the car after I turned the car off for about 5 minutes, but I realized I haven't heard that sound for quite awhile.

 

just plug the solenoid with a vacuum cap