Well i finally went to the track today after installing my cam and rr's. The car has everything in my signature. Well i went there and all 3 runs this problem happened... I flashed the stall and it hooked with a 1.9 60ft time but when it went to shift to 2nd it hesitated and i assume it hit the rev limiter because it backfired but it would last a second and shift and it the same thing again when it went in to third. This was very disappointing. The best ran i got was a 14.2. Does anyone know whats causing this to happen? I got the computer tuned by MadZ28 so i know its not stall wall. Any ideas at all?? Someone said it was my trans and others said its my converter so i have no clue. Can some please help me out and put me in the right direction??

This was my best run...everything else was high 14s and 15s

R/T .514
60' 1.955
330 5.785
1/8 9.022
MPH 73.87
1000 11.880
1/4 14.261
MPH 95.07



94 Camaro Z28 A4 with 3200 Stall, 3.90, Headers, Borla cat-back, cc503, 1.6rr, 52mm tb, 24#SVO Injectors, SLP CAI, Mad Z28 Tune, AIR! EGR! Hoosier DRs, Aluminum DS, Strut Bar, SFC, and all other bolt-ons and free mods you can think of!!!

 

If it's hitting the rev limiter, then he needs to change that for ya. The cars used to have a problem where a stall over 3ooo would cause a trans slip diagnostic to put the trans into limp home mode and a 1-3 shift, but most tuners know to switch that off and it doesn't sound like what's happening to you. I''d give him a call and see what he says if you can't look at the tune yourself. What rpms do you think you were seeing?

Now if it isn't the rev limiter, then other possibilities are plugs too hot, detonation, or valve float, but I can't tell much from your description.

 

I've just emailed him about it. I'm pretty sure he got rid of the stall wall because i made a mention of that when I was talking to him before. Do you think its my trans? I wonder if there isn't enough line pressure or something to get it to shift up to the next gear. It will shift it just takes a few secs.

 

Anyone??

 

throwing something out there. the backfire sounds like running lean like maf reading low and would cause shifting and backfire probs. just guessing

 

I think it's because it's hitting the rev-limiter that's making it backfire

 

Hitting the rev limiter shuts off the fuel on these engines. I've hit it a few times and there is no backfire. Something else is clearly incorrect.

Is there an error in your signature? You show 24 pound SVO injectors....about stock size even though you have installed a cam, etc. I think you're under-fuelling this engine, causing hesitation. Of course, if you've increased pressure to over 50 psi you'll probably be OK...

What plugs are you running? What gap? Any codes, even those that aren't setting the SES light?