1994 Corvette Cam Change

[Coltomi]

Hi,

I just finished installing and breaking in my cam yesterday and started tuning today. (I will post specs below) The first drive I took it on it ran on the lean side. I am using EEHack for datalogging and TunerCats for tuning. So, I increased the AFGS by 10% across all four MAF tables. This definitely made the car run much better but it still isn't right. For some reason around 3000 rpms and under load sometimes it would fall on it's face like it died for a split second. Looking at the datalog, at those moments the AFGS spikes to 450 g/s which is very unreasonable. I have driven the car around at varying throttle (except WOT) and under different loads to analyze what it does. I have done a ton of research on tuning my car so I have a decent idea as to what is going on. Also, I notice the left and right BLM's are not staying close to each other. (vary by 8 to 10 from one another). Any help is greatly appreciated. It wont let me attach my datalog file but I will happily email to anyone who is willing to help.

Specs: Cam: 222/226, 113 LSA, .530 lift
Long tube headers
New Petris Optispark

Thank you!
Coltomi

[steveo]

lets see that log. you can zip it and it'll let you post it.

[Coltomi]

Awesome thanks!
Here it is

[spfautsch]

at those moments the AFGS spikes to 450 g/s which is very unreasonable

It is. I don't think anything in your tune would cause that but I'm by no means qualified to give advice in that regard.

That extremely large airflow # is exactly what my MAF was reporting all the time after I damaged it trying to clean the sensor wires. I'm sure the stumble you felt was due to a massive amount of fuel being dumped causing a flood. Just speculation, but you might check the power lead going to the MAF for breaks - i.e. wiggle the harness while logging with key on / engine off and see if afgs jumps like that. Also try gently tapping the MAF housing.