Hello,
My son has a 94 Z28 with the LT1. The car has been running great but a few days ago it started having an issue, when he gives it gas to pull from a complete stop. When the car is given gas it will start to accelerate but it will cut out (it happens quickly), the engine and all the electronics. If he keeps his foot on the gas it will pick back up and take off. It will also do it if he is driving at 50 mph and he gives it a little more gas. If he takes of very slow it will go just fine.

Any help to narrow down the issue would be greatly appreciated.

 

Have you scanned the PCM for codes?

Have you ever had a problem with the ignition switch, while trying to start the engine?

 

I'm moving this to the correct forum. “New Member Intro....” isn’t the best place for tech issues.

 

No I have never checked the PCM for codes yet, we have never had an ignition problem with this car either, it fires right up every time. The weird thing is it will idle fine if we rev the engine in park it never cuts out.

 

So it mainly cuts out under load?

 

Almost sounds like when the engine torques seriously, it loses a ground, possibly loses the 12 volt supply from the battery, or the ignition switch takes a hit.

What is included in “all the electronics”? Does the dash go blank, do the exterior lights go off? Do accessories like the radio go off?

 

I’m having the same issues!

mine will start an run, when I get up too 3000 rpm it will start missing an backfiring real sluggish. I can pull over in my 95 trans am 6 speed an turn the switch off an open my door for 5 seconds (thinking to reset something) then fire it up like nothing happened about 10 mins does it again it’s a random. An repeate process. Y’all gentlemen’s knowledge would really help thanks in advance

 

Actually, his problem and yours may be a bit different. His engine simply shuts itself off. Yours keeps running, but runs poorly.

For you to get the best help, and to avoid confusing the responses to the thread starter's issues, please copy and paste your post to a new thread in this forum (LT1 Based Engine Tech).

Thanks!

Fred / Moderator

 

All the dash lights, radio shut off and come back on. I am not sure about the outside lights we only drive it during the day. When everything shuts off it is only fir like half a second.

 

Sounds like you are temporarily losing switched 12V power. Starts at the battery, to the red plastic battery box on the passenger side inner fender, passes through a fusible link that attaches the wire to that box, then to the ignition switch.

http://shbox.com/1/ignswschematic.jpg

Is there excessive movement of the engine due to badly worn engine mounts, or broken transmission mount?

I've watched problems with the aging ignition switches increase significantly over the 20+ years I've been helping on this site. But something would have to be impacting the steering column under torque loads that cause the engine to move excessively. The fact that the radio cuts off indicates the RAP module is losing unswitched 12V power as well (assuming your car has RPO AU3 - power door locks) would indicate the power interruption is occurring before the ignition switch, and before or at splice S200 shown in the wiring diagram linked above.

 

You could have the battery rocking backwards and shorting out on the AC accumulator under acceleration... also double check that both battery terminals are tight enough.