I konw this post is a bit long - please bare with me...

this has really been driving me insane.I haven't been able to get my car to pass smog.My extension is up in a week and im starting to freak out.I cannot get it to stop miss firing in cell 6.she starts missing between about 1500-2000 RPMS so I have to give it a bit more throttle and kick it to cell 10. I have replaced the entire ign system except the ECS and distrib, this helped slightly but not much. The car does it much worse when its cold and damp out. I wasn't always sure i had the injectors hooked up right(connectors connected to the right ones) since the car sat for 3 years till i put the new engine in last year - the numbering on the pieces of tape i had placed faded. although from a search I did on the boards I gathered the batch system fires them all at the same time - At least thats what i gathered...

I had been getting the the VE tables nailed down the past few months - What confuses me though is the car is reading 128 when its missing - though the 02 seems to stop cross counting (stays under 300). I figured then it must be spark advance - so i messed with the AE -tried moving it a few degrees either way but it didn't seem to make much of a difference =/ - my cam isn't that big - so im really confused now - the car has been doing this since the new engine - I got it to pass (barely) last year by telling the car it had a 305 instead of a 350 - they made the smog laws harder apparently though... It's just the hydrocarbons that are high, everything else is fine.

If anyone could help me I'd love you forever as I have no idea what im going to do if i do not have a vehicle next week

 

Pulling out timing *almost* always reduces HC's, without affecting the other emissions significantly. I can't tell from the message what or why you would be messing with AE - to me, AE stands for Acceleration Enrichment - which is not spark advance related. Removing some timing in the low load regions generally leads to easier combustion - reducing misfires, and hotter exhaust - which helps the cat(s) and allows combustion to continue until finished. It worked for me - I did it with a chip - had previously failed twice, before the Autoprom showed up. I just put something like 20 degrees in the low load regions (vs over 30), and tested it at work, and it really cleaned it up (bought the car with a burnt plug wire, so I'm sure it aged the cat quite a bit before I fixed it, the cat was definitely struggling).

You're right about the batch fire firing all injectors simultaneously, so don't worry about the injector connector mismatch.

The EGR may be leaking too much, or turning on too much. Do you have to take the full on-dyno test, or just the free-rev test? If it's just the free-rev test, you can disable EGR with the chip, but if it's leaking on its own, that won't help.

How bad is the misfire (how high are HC's)? Can you hear it running rougher? I'd expect the timing trick to work, but if not, I dunno, could be injector related, or vacuum leak, or compression related.

 

The HCs were 396
It starts kicking really hard when it starts to miss
I can drive around from 1000-1400 rpms fine it's just that 500
rpm window from 1500-2000
ill try pulling some more timming and see if that helps
- just now i tired putting my old bosch O2 back in to see if it made a difference and it started smoking wildly - i have a vaccum test gauge here - ill report back what its reading after i eat dinner and stick my GNX O2 back in