Northern KY or Cincinnati trucks???

Hey guys, I hope you can help. Ben's cobalt ss has a check engine light on. The code of P0507 which reads as Idle Control System RPM High. Here's the thing, it is idling low. When the car starts up, it's fine. If you let control off of the clutch, with it in neutral, is starts to pupupupup with an rpm around 400...so the code doesn't match what is happening. mind you, i suppose it is possible that it could be the tune. maybe it is running rich? the battery was just replaced as well as the oil changed. It drives fine with no problem, its when it idles, such as at a stop sign or red light. I remember reading some posts that somebody is a mechanic/works on cars? HELP!

 

Did it just start since youve replaced the battery ?

 

Nope. I should say it has been garaged for about the last 5-6 months, periodically starting it up. It started when we first started it up yesterday, well it actually wouldn't start. So, hooked it up to a charger and it ran like crap at idle. it is a 2006, so figured it was time for a new battery anyway and bought one. It doesn't appear to be related to the new battery, as it did this after the old battery charged.

the pulley on the harrop (after market replacing the stock) blower is 2.95, if that might help.

 

here is the site is love to use when i have a car throw codes.

http://www.obd-codes.com/

P0507 = Idle Control System RPM High

found this in a cobalt forum "It's probably something to do with how your software (aka tune) relates with your hardware (aka powertrain components). I had all sorts of issues with my mods in my Grand Prix; That's why I stopped doing performance mods when I bought my balt."

http://www.cobaltss.net/forums/2-4l...6/high-idle-2k-code-p0507-please-help-153524/

looks like it might have something to do with some of his mods. a hint i saw was that he may need to replace the injectors, to much fuel with his setup.

edit: there is another post in the above forum saying that a guy spent $600 chasing the same problem only to find out that a vacum hose was loose....

 

jesus you had that on a neon how fast was it?

 

i think he said 260 something a while back? I could be WAY off though

 

Yea, 260 was like factory. Lol. I never actually got it tuned. But it was around 420ish.


Battery issue. The battery could have gotten so low, that it reset the calibration of the computer, which was in the tune. So maybe now the tune has been reset. What device do you use to tune with? Maybe reload the tune back into the car.

 

lol he says 420ish like its no big thing! lol

 

Ya, I saw those.

The injectors are maxed out. But, I am not sure that would impact idle really. I don't know how to check for vaccuum leaks. Our friend has a tune system, but he lives in Dayton, so we don't get to see him often.

I suppose we should do the following:
1. check tune
2. vaccuum leaks

bah!

Also, crappy fuel? has always been run on 93/94. after sitting, fuel additive/cleaner was additive and 1/2 tank was added to existing 1/2 tank. Maybe after running off the old gas it will correct itself.

 

What is the engine size of the 2006 Cobalt SS? 2.2?
Is that thing the turbo cobalt?
Is it modded performace wise? Did you guys have it tuned?

You can start with the 2 most basic/important pieces of informataion to start help diagnosing.

#1. Fuel Pressure. A fuel pressure gauge with a schrader attachment is needed. Attach it to the fuel rail. See what kind of PSI you get with just the key on, then what kind of PSI you get with the car running.

#2. Engine Vacum. Need a vacum tester. Typically the brake booster vacum line will work well for this, but just find some kind of vacum line that runs into the intake manifold, disconnect it, plug the tester into the line and start the engine. A good vacum should be around 17-20 Hg at idle.

 

Sad part is, of my "Car scene" friends, I had the slowest car. Lol. Most run 11 second to 9 second quarter miles and trap 120-150mph depending on car.

If I got mine actually tuned, and on a good run, others have done High 10s Low 11s at 125+ mph

But I never did it, so I wont assume.

They shouldnt be maxed out at idle though.

I wouldnt really say its a fuel issue, if it just an idle problem and it kind of just started.

Boosted cars, defiantly check vacuum lines. I know on the SRT, that was the main issue for alot of peoples problems. Small pin holes in lines.

Could have an IAC sensor going bad also. When car is running, find the IAC and just tap on it, and see if the idle changes.

But honestly, just sounds like a vacuum line problem. Or again, the battery could have gotten so dead that it reset the computer which caused the tune to reset the memory of the drivability of the car.

A cars computer "learns" your driving habits depending if your a granny driver or a race car driver. So once the computer is reset, it doesnt store that "learned memory" So it has to relearn it, so it may just be that you have to drive it around the block a few times.

 

2.0 It is supercharged, not turbo, with an aftermarket harrop blower replacing the stock blower. psi hits between 18-20 depending edit: when driving , over 300 horses. it does have special tuning because of multiple mods. Ya, I think vaccuum check is best at this point. Thanks for the info!

If the computer reset and the tune was out, there is no way the car would run. The tune is specific to his set up, so I really don't even think it would run if that was the case. I'm hedging toward vacuum leak also. I will keep you posted, thanks so much.

 

This Kate?

 

BTW you can check for vacuum leaks with the engine running. Spray a little starting fluid around the fittings and such and if the idle changes it is likely that the starting fluid is being pulled in through the vacuum leak.
That how I found the leak on my MB SL.
Good Luck!!!

 

That was a nice show, I was hoping you got a picture of the new Aston Martin Virage. If I had the money, that would be my buy. Thanks for sharing.

 

Reallly thinking about attempting the BHLM today.

 

Good luck, let us know how it turns out!

 

D/S HL (#1) is in the oven!

To late now...

I'll make some posts while I'm doing it.

 

may be bad gas if it just sat in the garage for that period of time. You said you started it a few times, but did you ever run it around? Try to run that tank out if you havent already and put some good gas in there as well as injector cleaner or octane booster. There my .02 haha hope it helps!

 

Holy Moly that sealant is nasty.

HL #1 is totally apart. Went OK. Did some cosmetic damage to the housing from prying on the 2 pieces to get them seperated, shouldn't be visable though.