Z28_1991_Camaro

I was driving on the highway today at about 120km/hr. Was doing 120ish for about 30 mins.
Then out of no where i get a back fire and I see a little smoke come from my exhaust. At this point if I step on the gas my car goes nowhere.
I pull off the highway and look under the hood, everything appears is in order except the negative cable on my batter was touching the small air tubes(not 100% certain what these are called) on my exhaust manifolds, hence the rubber was melted around the wire.
I presumed this was creating some kind of short and screwing with the compter.
I fixed it so that the wire was no longer touching and got back on the highway and the car was fine for about another 5 mins or so then it started back firing again. It would do it ever 5-10 seconds.
I pulled over again to see if maybe the wire from the batter had come lose again but it had not. I turned around and went back home at this point. I set my cruise to 100km/hr and drove back home with no problems.
It seems as if the problem only came about when going faster than 110-115km/hr.
When I got home I brought it to a logal garage for them to take a look at it. The guy took it out for a drive to see for himself what was wrong. As I waited, the phone rang and the receptionist was cut off and I knew right away that it was the guy who took my car out for a test drive and that something was wrong. Sure enough, the receptionist tells me the car died on him while under load and he couldnt get it started back up again.
So my car was supposed to be towed back to the garage tonight and they are going to take a look at it tomorrow morning.

I have minimal knowledge of vehicles but this just doesn't make any sense to me.

Any ideas what could possibly be my problem?

camaronewbie

check plug wires - every backfire I ever had was an electrical issue, not a fuel issue. they need to check continuity on all plug wires, and check spark on all cylinders.

Z28_1991_Camaro

The garage suggested I change my pickup coil, tps and module. What is a module?

They said that may or may not fix my problem and they want to charge me $1000 for parts, labor and diagnostics.

I started my car when the tps was unplugged last week and becasue of that I got the code so now they think it's a problem.

They also said my pcm may need to be replaced, he said gm's especially as old as mine are known for these types of problems.

I replaced my plugs and wires about 2 months ago so I doubt it's that. How exactly would I go about testing my plugs and wires?

woody88iroc

I had a problem just like this...checked electrical systems, so ignition, distributor, wires...changed it all.. Then if that doesnt seem to be the problem, could be fuel. I had the problem still and replaced fuel relay and then fuel pump.

Havent had a problem since then.