DannyG123US

1988 5000 CSQT idle will fluctuate from 1500 rpm down to 400rpm when i come to a stoplight the check lights (battery, antilock,etc) car will flash one time it fully turned off and had to jump it any advice would be highly appreciated

richard-tx

If you had to jump it to get it going, get a new battery or fix that issue first.

bradwilcox

Is it because of the chip or is that just coincidental?

Bad alternator? Belts? Ground? ISV? Fuses missing or broken (check ALL).

GroupBquattro

If you think it's the chip, do you have another ECU to replace ? Was it running all good before the chip ? The car should run fine even with the ISV disconnected, you can try that. The belts can be easily inspected, but usually they only make noise, or if they are loose, you can tell. Doubt it's the alternator.