newmexicanz28

ok so i bought this car over the weekend and i paid 1k for it knowing it had issues. well i have fixed the issues and it still runs like a granny car when it gets warm, and this morning i drove to school and left 30 minutes later and it wont start. so here is alittle background on the car. it is a 96 z28 with a new optispark and plugs. it has a 6-AL installed and msd plug wires. also it has headman headers with turndowns installed. the issue is when it gets warm the car runs like crap and wont wanna start. could that be because there are only the front 2 O2 sensors installed? i am throwing codes for the 2 rear O2 no activity and random cylinder misfire and 1661. which is cause they removed the CEL and i cant figure out how to get the dash off yet. also the MAF is cut up on the inside and the guy i bought it from said it was bad but im not getting any codes for it. is it possible to have a bad MAF and not throw any trouble codes? if you guys need anymore info please feel free to ask. i dont wanna drive this car anymore till its fixed but its oh so fun.

camaro383tt

https://www.camaroz28.com/forums/advanced-tech-38/notice-what-forum-what-not-please-read-47092/

one of the other forums may yield better results

Injuneer

Moving to "LT1 Based Engine Tech".

ACE1252

First, you do need to get a F-body LT1 MAF that is stock. From my understanding, nothing but trouble comes from a MAF that is ported/cut up and not properly re-calibrated in the PCM. Do not de-screen it....leave the screen in it.

What brand Opti was installed on it? Are the plug wires burned? Plugs look okay?

I don't have any experience with a 6-AL so others will have to chime in on it....but it might be wise to take it out of the picture until you can nail down the misfire issues(trying to eliminate misfire possibilities).

The rear O2's are mainly looking for cat effectiveness. The factory manual states that they do play a minor role in fueling, but I don't think missing them would make it run so badly warm(but I could be wrong).

Guest47904

Misfires have to be cured first.

When it's warm, it could be running poorly due to bad closed loop control. You can find out by disconnecting one of the front O2s. This will force it to stay in open loop. If it runs ok after it warms up, you know it's a closed loop issue.

However, the source of the misfire must be corrected first. The MAF issue has to be addressed as well. Also need to get the SES light working. If I remember correctly the bezel around the gauges is merely pushed in. So all you have to do is pull it straight off. Bolts for the gauge cluster is visible underneath.

Rear O2s are only for cat efficiency, do not have anything to do with fueling. If it's due to not having cats, best to just get simulators. So the PCM thinks they are working like these: http://www.o2simulator.com/index.php...997c1475dd8183

ACE1252

From the factory manual. Read what's in the red square....