It all started back in the winter of 05 when I pulled the 77,000 mile motor and started modding.

I had installed a LT4 hotcam kit, 94+ style vented MSD opti, MSD coil, MSD wires, MSD 6AL, Stainless Works longtubes with high flow cats, 3" B&B exhaust, electric waterpump and a PCMforLess tune.

After all this, the car had a skip at 2000 rpms so I brought it to a local tuner in Spring 06' who burned me a new chip and I've driven it like that until it cametime to check for emissions in July 07'. The car failed, running way too rich. Here's the info...

HC PPM at idle = 623, limit was 220
HC PPM at 2500 = 128, limit was 220
CO % at idle = 2.97%, limit was 1.20%
CO % at 2500 = 2.94%, limit was 1.20%

Since then, I've replaced all injectors, spark plugs and installed Delco heated O2 sensors. Also, I've purchased TTS Datamaster to help me understand whats happening. I've brought the car back to the original tuner and never got any help. I've brought the car to a mechanic to do a leakdown test....cylinder walls and heads are on good. I've also puchased a new tune from PCMforLess.

Here's my take from Datamaster... Engine at 200, oil at 190

1)Lterm Always stays "red" which means rich
2)Sterm in closed loop turns red, open loop returns to 128 counts
3)car goes in and out of closed loop
4) open loop makes RPM's jump by 100
5) MAP, 50 KPA at idle, 80 when on the throttle, 18 immediately after off the throttle
6) TPS at 6000shows 50%, 1.96 V
7) one O2 hovers between 400 and 600mv
8) one O2 in closed loop between 100 and 900mv, hovers around 800 in closed loop

anything you guys would reccommend?

wow... my first thought... something is amiss with the fuel management.

7 and 8 are what throw me. The 1993 uses a batch injection, that means all 4 on the left fire at once, followed by all 4 on the right and back and forth.

it seems to me, with those numbers on the O2s, something is out of wack there.

I wouldnt worry about the O2s at this stage, id be more concerned about correcting the issue. The O2s are apparently saying its rich, and according to the emissions test, they are not lying.

#6 is a mystery to me, what the hell are you talking about here? 6,000 what? If you mean its showing you 50% TPS at 6,000rpm unloaded, there is nothing wrong with that. To test the operation of the TPS, turn the key on but dont start the engine, then with DataMaster on, slowly push the pedal down and watch to see if the % and the voltage go up reasonably smoothly.

#5 seems pretty normal operation, but id like to see the log to know more about the conditions youre seeing 80kpa.

#4 id be interested to know what the idle rpm is in the first place, what its set at in the tune, and what the actual idle speed is in closed loop.

#1 Lterm in the red doesnt mean its rich, it means its attempting to correct a rich condition its seen. If it gets down to 108 and stays down around there, it cant correct enough.

You need to get this car out on the road and do a data log of some regular driving, some spirited driving, and some idling hot and cold. Then email that to me so i can see what i can see.

sonomacrew01,

Any update on this problem or solutions?

On Friday, I brought the car to J&M Corvettes in CT. I've been in Nicaragua since then and I have had no update. Very anxious.

Is this the Ruby 'vert?

Beautiful car! I hope you can get it sorted!

yeah... I had some plans for it this winter but looks like funding will be spent trying to get it running right...

I bet the problem is in the tune.