I have another problem after my cam swap, the engine is backfiring nearly each time I step on it. Never from dead stop but each time I am driving and I push the throttle, I can hear a big bang and the engine stops for half a second.

I had trouble with my ignition so I brought it to a "reputable" mechanic to have it set properly but it still backfire.
What is wrong?
I didn't bump the fuel pressure or change anything from the ignition and TBI
Is it because of a lean condition?
I have a small oil leak from the rear of the manifold.
I have headers, and the cam was an LT1.
The car doesn't run good neither, it makes real power at nearly 4000 rpm.

Sorry for the lenght but I really don't know what to do.
Thanks for your answers,
Jacques.

 

Check your plug wires. Could have a few crossed. I had to straighten out a friends TA today because he did this same thing. Car wouldnt run well, and would pop and backfire. He had the #8, #6, #4, and another plug wire Ive forgotten crossed up.

 

Did you ever get it straighted out? Mine ran fine for the first 100 miles today, but then coming home I stepped on it and it backfired.

It doesn't have real good power, but as good as a expected from stock fuel delivery. I plan on bumping the fuel pressure in the next week or so.

 

Keith5,
Just curious on how the LT1 cam compares to the stock cam powerwise.
As far as fixing problems, some of the things I've read on this board include: bumping the FP, advancing the timing to about 8*, and checking that the timing chain is installed correctly. Of course, burning a prom is all important as well.

 

I did find the problem, it was the bolt that hold the distributor in place that was not tight enough.
Each time I would adjust the timing, while driving, it would slightly turn and retard the timing to a point where it was making the car backfiring.



Now it runs fine, after many tries, my timing is set at 14° btdc.
There is definitly an increase in power in higher rpm.

 

I have adjust some more on mine, it's at 6* BTDC now, it seems to be running good there for now. I need to bump the fuel pressure now. I've noticed my entire power band has moved up about 2000 rpms, there will be a lot more power there when I get the extra fuel in there, right now it may have like 20 extra horses, it's starving for fuel bad.

I didn't just do the cam though, I did heads, headers, intake and cam.