Finished my engine rebuild on my 1998 civic ex and i drove it home and the same issue happened again before the rebuild. Car has a terrible idle. If I push down the brake pedal hard at idle it will surge and drop below 100 rpms and almost dies. If i turn the steering wheel it will do the same. If i hold down the window switch it will do it too. Battery is good. Fully charged. Tested the battery. Brand new Alternator. Replaced ground on battery. The battery light is on in the car. Also there is no Catalytic converter on the car, not sure if that would cause the poor idle. I'm thinking maybe a vacuum leak somewhere. Cruise control doesnt work either. Could it be an electrical issue? I know the alternator and starter and battery is good. Tested all of them. 13.8v battery after starting the car so alternator works. Gonna pick up some carb cleaner tomorrow morning and start spraying and look for leaks. What would be the most logical explanation? Has this happened to anyone else?

 

The battery light is on for an electrical issue, obviously. Are your engine/trans grounds good? 1valvecover, 1or 2 in engine harness and 1 from trans to subframe. When you push brakes, brake lights come on(electrical load+vac load). Window switch creates electrical load. When you turn wheel, it creates load on the pump(mechanical). Cruise control= electrical/throttle cable. Its looking like an electrical issue. Do your headlights flicker/dim when you push brakes or turn the a/c on?

 

no valve cover ground but the other grounds were fine. Would not having a ground there be a big issue? and headlights do not flicker or dim with a load on it

 

I would put a v/c ground on and see what happens. You can use #8 speaker wire if you have any laying around. That ground is there for a reason.

 

More grounds the better. Completes the electrical circuit

 

checked for vacuum leaks today and found nothing. sprayed carb cleaner everywhere all over the intake and trottle body and all vacuum lines including the cruise control and nothing. So it HAS to be an electrical issue. I highly doubt that the valve cover ground will fix all the problems because i am ever that lucky buut i will give that a try tomorrow and let you guys know