More Problems

Stableboy

Founding Member
Nov 29, 2001
91
0
6
Perryville MD
Hi all, more issues with my 90 auto vert. Took it out today (almost 60 in MD) for one last topless ride. Car had its now normal and phantom irradic idle after warmup, but when I came home I was putting top up and car stalled out. That is not the wierd part. The entire car died. The tach was stuck at 500 rpms, when I cranked it nothing, but the tach went to NEGATIVE 1000 rpms (est) Headlights worked though. Did this for about two minutes, pulled key out tried a few times and then acted normally. Key in turn and start. Very strange, it was like the car had a totally dead battery. Never seen a tach go negative rpms while turning the key to start position. Any thoughts?
BTW friend said MAP sensor could be bad and causeing erratic idle after warmup any thoughts?
 
First thing I would do is pull codes. A failed or failing sensor will store a code in the computer's memory. If there are no codes, I would somewhat suspect either the idle air controller, tfi ignition module, or possibly the ignition switch.