L98IROCZ89

My car is running pretty dam rich... killing the brakes(impossible to stop the car) and the tranny(bangs harder than ever before).

Background: My fuel pressure is at 50psi... I know that is high, I had it set there to race and havent set it back to 46 yet. However, It was not running rich like this for the first 3 weeks it was set at 50... this is only recently.

Also, I have recenetly taken the Hypertech chip out in favor of the stock chip. I figured maybe the car didnt like the stock chip with the mods I have, some of which tend to richen up the mixture... but that didnt make a difference either.

Then maybe I thought it was thje 160 thermostat and that the car was in warm up mode. Today, I was in line for inspection, and the car heated up to 220 and it was still running rich at that temp, so thats not the issue either.

I did have a BAD header leak though... could the bad header leak have ruined my O2 sensor???

Any other advice, suggestions, or opinions are welcome.

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1989 Chevrolet Camaro IROC-Z
L98 - 350c.i. TPI, rebuilt 700R4 auto w/shift kit, Dual catalyst Monza PaceSetter Cat-Back, SLP 1 5/8 Coated Headers, 3.23 Posi rear, Hypertech Thermomaster chip with 160stat, MSD 6A, March Under-Drive pulleys, AFPR, K&N's, !Air Box w/ Ram Air, moddified MAF, !TB Coolant, Spohn Dual Cat SubFrame Connectors, Alarm, Keyless entry, remote starter, 92 Z28 AeroWing, Brand New Paint (6/21/01)

Future: ZZ4 TPI w/EGR, T56, 3.42 or 3.73, Spohn strut tower brace and LCA's, Accell Universal 24# injectors

More info and pics on my webpage:http://go.to/iroc-z

AOL IMer: GPA 0point0

ZZ4Vette

I dont know the answer to this one, but L98IROCZ89 car has been doing a lot of this recently.....
haha
just kidding bro!



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91RamAir Formula

are you sure it is running rich if so why?


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91 Formula 350 TPI,ASCD RA hood,1.6rr's,aluminum driveshaft,SLP 1 3/4" headers Mufflex3.5",AS&M SSM runners matched plenum, chip,TCI trans.

RWHP=261 RWTQ=349

mckenzie

if you have an exhaust leak in front of the o2 sensor, it will cause a lean reading. you will have an exhaust leak, but also a vacuum...sucking the outside air downstream in front of the o2 sensor. fix the header leak and see if it helps. best of luck, tom

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86 iroc 305tpi auto. mild cam

L98IROCZ89

I already fixed the exhaust leak and it is still running rich.

I am sure it is running rich... MY CAR WONT ENGINE BREAK!!! It is getting enough gas to keep the car at a constant speed with your fott off the gas. And if you pop it into neutral when your stoppped with ur foot on the brake, the rpm's will go from 750 to 1100. It is most definetly running rich... I definetly need to turn the fuel pressur down to 46 and put the hypertech chip back in and see if that helps.

8Mike9

Your high idle would be more likely to be a vacuum leak than too rich if the A/F mixture is causing it.


With the engine warmed up try this...jump the A and B terminal on the ALDL with the key on, engine off..wait about 15-20 seconds, then unplug the IAC connector.

Start the engine and see if the idle is/stays lower...if so, then suspect the IAC valve or operating parameters for the IAC control.

tpi_roc

I agree, a 'rich' condition would be less likely to cause the problems you're describing, lean conditions can cause your idle to be quicker than normal.

Look at it from another angle

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