SSSLP02

I installed the MS3 113LSA with pushrods and dual valve springs in my 2002 Camaro SS, the day I finished it I took it out for a drive and everything seemed to be fine other than it wouldn't really idle since I had lowered the idle to around 600rpm with my previous tune. I lengthened the throttle cable only to keep the car from dying, as I knew I was tuning it soon and didn't want to drill the tb or anything stupid like that. I came back home (car has not yet been over 2500rpm.) The next day I get it out to take a little drive, about 45 minutes into the drive sitting at a light it all the sudden wants to die, and it is hard to even sustain a good idle, seemed like I could push the pedal almost halfway down without alot of response, kind of doggy, I also noticed it was excessively rich (smoke and smell). The car was popping, surging, and had zero pull until about 2000rpm then it would want to blow the tires off. I had one new code0106 Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem, which I did some research and found the range for the sensor needed to be adjusted due to intake port reversion, I adjusted it and the code went away but it still had a hunting idle problem and was also slow to fall back to idle (925rpm.) I have 2 other codes which are for the o2 sensors because I am running long tubes with offroad Y pipe and run Avgas only (100 octane low lead) but neither have caused any problem before. Basically I have gone over all vacuum lines checked the TPS voltages checked all grounds, and I'm about the throw in the towel! Anyone had this problem or have any suggestions? Thanks in advance, sorry for the long post!

SSSLP02

I forgot to mention that the car has since been tuned using a Texas Speed tune as a base, and the same problems still exist.

Doobie52

iTrader: (23)

Stop running AVGAS. Leaded fuel ruins O2 sensors. Start by replacing your O2 sensors because if you've got a couple hundred miles on them, they're now shot.

DREAMZ28

iTrader: (1)

I didn't know people still sold leaded fuels..

Doobie52

iTrader: (23)

AVGAS is also know as 100LL or 100 Low Lead. I don't know of anywhere you can get it except at an airport. I had a friend who used to fuel small private aircraft and he would give us all we wanted. Of course we were putting in in carburated cars not fuel injected. The US Government stopped putting lead in fuel because of catalytic converters and O2 sensors specifically. It's great gas, just not for a fuel injected car. I think I've also read that leaded fuel isn't good for injectors. Someone can chime in on that if they want.

35th SS

iTrader: (2)

just FYI a po PO106 code low vac./idle.raise your idle to around 900-1000.go from there.what others said.replace your o2s or clean them.

SSSLP02

Well have been running 100LL for 2 plus years now with no problems ( tuned with hptuners). I took your advice and tried 2 new sensors, but I still have the same symptoms. As for the idle adjustment, that should not be a factor since I have adjusted map tables, I will try that also, what's a good idle rpm? I just don't see how this could start out of nowhere, that's why I also think it's not in the 2 tunes I have.

Slowhawk

iTrader: (12)

The answer would be in logging the car with a scanner.That should tell what the problem is.

SSSLP02

I just saw the idle suggestion from 35th SS, but my idle is currently set at 925??
Slowhawk, what do you mean by "logging", I have already scanned the car with a hand held scanner and only the o2 codes show up if that's what you mean.

Slowhawk

iTrader: (12)

If you can find someone with HP tuners or EFI live it will save you a bunch of trouble.

We do it here for $25 .I drive the car while logging and check the sensors.

DREAMZ28

iTrader: (1)

O ok thanks for the info.

BlueMagicSS

iTrader: (4)

Logging basically means to drive the car and record the data from the sensors on a scanner. By looking at the recorded data you can find which reading is off therefor fix the problem easier