hyperzone

I have a 97 camaro, 6 speed, with the computer and motor out of my late 96 SS. I only swapped the computer so that I could still use LT1edit that I bought for the 96 and is supposedly locked to PCM. I even swapped the BCM so I could use my old keyless entry stuff since the new car didn't come with the remote. While the motor was out for the switch, I put in a LE 218/224 cam. Lastly, this new body I have is setup for coil per cylinder which looked to my knowledge like the LTCC setup so, I assume it is.

Everything was installed and car ran good for about 3-4 weeks of very minimal driving. had to clean it up, had to get an alignment first, needs a tune, and just had to get it done around my work schedule. So, on the way home from alignment, the ALT crapped out. No problem, running on the battery about 2 miles to autozone and swapped it out in parking lot. That was the last time it ran good.

Now, under any kind of load condition (going up a long hill, stomping on the throttle, or just trying to use 6th gear anywhere) it stumbles. I dont know what to call it (detonation, misfiring, stumbling, bucking) I just know it sucks and I'm not sure what is doing it. It does it at any RPM when you give the engine some load although, if you drive super easy like grandma and keep it in a lower gear it will drive smooth throughout the RPM range

I do get an occasional TPS high voltage code (used to get it randomly on the SS) ever since I put on a different TB. I have drilled and adjusted the TPS to adjust for correct voltage using a multimeter. It doesn't happen often and usually clears itself on the same drive. I've ordered a new TPS and it will hopefully fix that issue. I have adjusted valve lash 3 times, Fuel pressure is 40-41 at idle and 39-40 at about 3500 rpm, does that sound right? I have no missfire codes. And finally, I was using a timing light to watch for spark out of each of the 8 coils and thought I found two bad ones. Might have been a fluke but, I replaced all eight to be sure they are good since they were a mix-matched bunch to begin with. Still no change although timing light looks good for each one putting out spark.

Could the tune be doing this? car drove okay on the few rides I had prior to ALT dying. I'm curious about the fuel pressure since this car looks like somebody already had worked on the pump (cut the access in the back). Just need ideas on what else could be wrong. I'd hate to ditch this ignition system but, if it needs to go it needs to go I guess... is there any better way to check ignition?

pro94lt

I'm not sure how accurate the "missfire code" is as I've got a obd1 car, but it sure sounds like a burned plug wire or bad plug.

gregrob

iTrader: (8)

Maybe the low voltage killed something. I would disconnect the battery for a while. Also you need to get it on a scanner and see what's happening.

hyperzone

I replaced the plugs after this started and it stayed the same. I've visually checked each plug wire and ohmed them out, and like I was saying the timing light will show that they are all sparking. What do you mean when you say "get on a scanner"? I have autotap and I could download a different scanning/logging tool if you recommend something. What settings, conditions or sensors should I be looking at? I ran it a little with autotap going and it shows that whenever I hit one of those "stumbling" conditions that the knock retard goes up.. I've seen it hit up to 7-8 degrees. At a warm idle, it will be at 1-3 degrees of knock retard although, if I rev to say 3000rpm sitting still, the engine revs smooth and the knock retard goes away and everything seems good. Then, if I say put it in drive or reverse with the brake on and make it work a little to move the car it will do its thing and retard timing again. Just driving it around, it feels like it wants to go and like the power is there, it just has this weird issue. I'm wondering if this coil per cylinder setup is to blame. I'm thinking about pulling out this whole ignition system and swapping in the delteq I still have from the SS. I never had any problems at all with the deleq unit so, if that ends up working, I could at least go from there.

I just dont know enough about tuning and computer controls to make much of the readings but, isn't knock retard something the computer induces when it senses a rough running condition?

nitrous2fast

iTrader: (2)

you shouldn't have any KR at idle.

hyperzone

I'm watching the autotap log file again and the KR bounces all over the place at idle and under heavy accelleration but, goes to zero when I'm cruisng at speed above 2500rpm. What is the norm for ignition timing advance? Is there a general number that you should look for?