92_Lumina_Z34

My parent 89 Corvette convertible has had a problem which corvette specialists cannot even fix. The car was driving fine and all of a sudden it started backfiring through the airbreather (a hickup as the mechanic called it). The car would not even stay running unless you were on the acclerator and it would die every time you used the brakes. I put some octane booster in it and it would stay running but had a terrible miss to it. So i drove it to a recommended corvette specialist and he told us it was the MAF sensor, so he changed it. It still did the same thing, so then he said it was the plugs, so we okayed him to change it. Still had the same problem. They replaced a couple intake gaskets and a couple vacum lines and it seemed to fix it. Two days later its doin the same thing. Sent it back and it was there for a week. He told us honestly that he doesnt know whats wrong with it and wished us the best.
The car is going to be put away for the winter in 2 weeks.
So any solutions to this problem would be great.
Thnks in advance for anyones input.

grfnkl

I have a similiar problem a vette as well... Have you looked into the Ignition module? That's another possible cause. I also heard somewhere that there is some computer control module that can do the same thing but they don't make it anymore? I cannot verify if that's the case or not on that part. I would say look into the ignition module, and make sure the fuel and timing are correct.

My problem still exsists at this time as well... but I need to drain the gas tank and try with fresh... that's where my problem lies that i know of.

__________________

cbec1999

Didi you get your cash back for the MAF?

Ijustdontknow

Just to cover all bases take a set of hose crimping plastic pliers and crimp off the vacuum line to the brake booster. I have seen instances where the diaphram in the booster is bad causing a vacuum leak which in turn will make the car run like its missing, and be gutless. You said it dies when you hit the brakes which reminded me of a caprice I worked on a while back. It had the Lt1 in it but the symptoms were very similar and it ended up being the booster.

cbec1999

Gosh dude... If he says MAF, and it ain't MAF, and then he rolls the dice again, why stick around (besides to get your old MAF back installed and cash back, of course)???

Lesson:
Let NO mechanic say words. SHOW ME. Corvette specialist? That's a funny. Right?

What codes do you have?

If no codes, check fuel pressure. Static (motor off), idle with vacuum ON FPR, idle with vacuum off of FPR, and pedal down (gauge taped to the windshield).

Does it lope at idle when warm?

K5Calamity

Was going to post something here, but decided that I have know idea what could be your problem accept to say I think it's possibly vacume related.