Small backfire through intake - 94 LT1

[manofthehour114]

I know this isn't S10 related, and I'm not even sure if this is the right section to post in, but you guys have been great to me in the past...

I got rid of my S10, and I have been looking at buying a friend's '94 Camaro Z28, but it has one small problem that worries me. When you stomp the gas it hesitates for a second, backfires through the intake, but then it takes off like a rocket.
The backfire isn't persistent, which is what confuses me. It idles fine, and runs great after it takes off. I'm assuming that it is a timing issue, because it wouldn't backfire through the intake unless an intake valve was open and premature detonation was occurring in one of the cylinders, right? Just an assumption, though.

- The car only has 96,000 miles, but is it possible that the timing chain has developed enough slack to advance timing for a few seconds when you stomp the gas, and then return to normal when it takes off?
- Is there anything on these engines that electronically advances and retards timing?
- MAF sensor?
- Any other ideas?

Any help is greatly appreciated! :D

[em98ss]

Ummm not 100% but sounds like a timing issue, if it was persistant it would more than likely be a flat spot on the cam.
Don't think it would be a fuel problem, just sounds more like timing

[vmss10]

Might want to go to fbody.com and ask there. I'm sure someone there has experienced it.

[manofthehour114]

I've posted this on about 5 different forums... LT1 and f-body forums. There have been a few cars doing it, but nobody really knows why. It seems to happen a LOT more often in the OBD 1 cars, like this '94.
I'm going to try to get my hands on a multimeter and see what the voltage readings are across the MAF sensor.
Also, my buddy has had the battery off of this car for a few months. How long would the car need to run to "re-program" itself? Could that have anything to do with it?

[manofthehour114]

After changing the plugs, plug wires, cleaning the MAF sensor and several other things... I found the problem.

The rubber intake elbow with the "donkey dong" that connects the MAF sensor to the engines intake had a huge split in the bottom of it. It was allowing the engine to suck in air that was bypassing the sensor. Since the MAF sensor was only reading a portion of the air that was being sucked into the intake, it wasn't adjusting for more fuel and it was causing a lean condition at wide open throttle.

I'm pretty relieved http://images.ibsrv.net/ibsrv/res/src:www.ls1tech.com/get/forums/images/smilies/LS1Tech/gr_grin.gif