[Bowtie Misfit]

95 Z28 LT1: bored +.030, CC 503, Stock heads, 30# injectors, 58mm TB, LTs, 3500 stall, Monster 4L60EHD, 3.73 gears.

I have had the car dyno tuned by 2 different shops, 2nd shop tuned x2. The last time I had it tuned, the tuner asked what I had changed cause the car was running very rich. Told him all that had changed since last tune was LTs, Stall & trans. None of which should cause rich condition, he didn't believe me. (like lying was going to get me anywhere?) Was having retuned for shift points.

1st issue: After every tune car runs good but it gradually richens to the point where the exhaust smells very rich. This happens slowly over about a month or 2. I have tried disconnecting the battery for 2 days to reset the computer but nothing changed. Changed MAF, no change.

Any Ideas on what could be causing this? I need to have it retuned because the shift points are still not correct but before I take it to a new tuner, I would like to get the rich issue corrected if it's outside of the tuning.

Thanks for any help!!!!

 

[Mystery Bird]

When it was tuned did they verify the AFR? Was it tuned for the larger injectors?
Just because it smells rich doesn't mean it is running rich. A lean condidtion can smell rich. Also, if you removed the cat converter it's going to stink no matter what.

 

[Bowtie Misfit]

Not sure what u mean by verifing the AFR. All 3 times it was tuned I gave them a printed list of all of the mods, including the injectors. I dropped the car off and they called me in a few days when it was ready. The last 2 times the owner/tuner test drive the car after the tune.

Recently I've been taking it to emmisions and everytime I go the readings have increased. I'm pullling the tags at the end of the month, they won't extend it any more.

Thanks

 

[Mystery Bird]

Air to Fuel Ratio. It should be printed on your dyno sheet. The tuner should be able to log some data and adjust accordingly also be able to see what's causing it to run rich. You could always scan it yourself with Datamaster to help track down the issue.

 

[Bowtie Misfit]

Yeah... Neither of the tuners gave me a dyno sheet, there was always an excuse why they couldn't print it.
I have everything for the datalogging but have to get a USB to serial port adapter.
So basiclly you believe its in the tuning?
Thnaks for your help!

 

[Mystery Bird]

Without knowing all the other variables I would look into tuning yes.