Hey everyone, this is on my 88 GTA.

My issue is while driving sometimes when hitting a dip, bump, rough road, etc. the RPMs will drop and the SES light will flash/turn on. - But literally within a second or two it will be back to normal as if nothing happened.

When I first bought the car it had a really rough idle - took it to a shop and they discovered a ground was incorrectly installed and the 'Computer' ground was loose. They fixed em, but the issue has come back so I want to check every single ground & maybe main electronics that could cause this.

Only electronics replaced are new battery & new starter, everything else is oem.

Any thoughts or grounds to check? thanks.

 

Do you see any dimming? Could check the fusible links by the starter. One of mine was blown but still making intermittent connection. Replaced all 3.

 

You know, I do actually see a "pulsing" dimming on my dash lights & exterior lights. I'll have to inspect those wires when I get home.

But could that cause the entire car to act like I just turned the key to off? Then back on when it re-established connection?

 

Sure can. They feed most the power to the car.

 

Sweet, I really hope that's the issue.

I haven't messed with them before, does it require a specific gauge of wire?

 

The fusible link is actually wire, pretty sure my TPI was 18 gauge (0.8 SQ mm)

 

This SCREAMS loose ground or knock sensor

 

Thanks I'll look into it!

Yeah I was really figuring it could be a loose ground.
Would it be a knock sensor going bad? or getting false readings? (car only has 82k miles and engine has no problems).

I'm thinking about adding another ground strap or two.

 

Definitely sounds like wiring. Have you tried shaking the wire harness and connectors while the car is parked and running?

 

Good idea, I'll try that now!

 

Thanks spurgeon76, I was instantly able to find the bad wire.

The previous owner wired the pass. side fan to come on if it hit a certain temp - come to find out they spliced into a wire that controls the fuel. (When you turn the key and this wire is bent/pushed you do not hear the fuel pump prime).

I also tried shaking the 3 fusible links while it was running and they seemed fine.

Going to do some re-wiring and I'll post back with my results!

 

Any luck?

 

Glad to hear you found it. I hate chasing Electrical Gremlins. I had a similar issue that turned out to be a loose connector on the Ignition Coil. I would hit a bump and the motor would shut off.