jymwhi
New Member
About 2 weeks ago I purchased a 1992 SHO MTX. Due to my work schedule I haven’t had the opportunity to really drive the car until today. I drove it for about 5 hours and put some 300 miles on it. It drove really well but it did exhibit the following:
1. When the car is up to normal operating temperature and with either the AC, Defroster, or Climate control on, when the AC compressor turns on, the car all but shuts off. The idle will drop down momentarily to about 450 to 550 RPM range, the RPM’s will then kick up to around 1200 and then this cycle repeats and will continue as long as the EATC is in either of these positions. This does not happen when all other accessories are on ie … lights, rear window defogger, fog lights. Does this sound like a alternator/charging system problem or perhaps a AC compressor drawing too much load or some sensor not picking up the idle speed when the unit kicks in.
2. After about 2 hours of driving I stopped at shopping center. I drove the car to 3 or 4 places and the went into eat lunch. When I came back out to start the car it fired up but ran rough for about 15-25 seconds. And then the idle smoothed out. I drove it to another location, went in for about 20 minutes, came out and it took 2 tries to start the car. On the second try, I pushed the accelerator pedal about 1/3 of the way to the floor and she fired up. Any ideas?
3. Also, during the above starting scenario, while just observing the car from the outside, I noticed water droplets from FWD end of both mufflers. I figured the exhaust would of dried out after 3 hours of highway driving. Any clues?
4. A little history on this car. It has 67K, 1 owner and has most likely spent more time sitting the past few months than on the road. The car drives very smooth and runs like a scalded dog when the throttle is mashed to the floor board. The engine idle after warmed up is 1000-1200 RPM. Is this too high?
Thanks!
Jim White
1. When the car is up to normal operating temperature and with either the AC, Defroster, or Climate control on, when the AC compressor turns on, the car all but shuts off. The idle will drop down momentarily to about 450 to 550 RPM range, the RPM’s will then kick up to around 1200 and then this cycle repeats and will continue as long as the EATC is in either of these positions. This does not happen when all other accessories are on ie … lights, rear window defogger, fog lights. Does this sound like a alternator/charging system problem or perhaps a AC compressor drawing too much load or some sensor not picking up the idle speed when the unit kicks in.
2. After about 2 hours of driving I stopped at shopping center. I drove the car to 3 or 4 places and the went into eat lunch. When I came back out to start the car it fired up but ran rough for about 15-25 seconds. And then the idle smoothed out. I drove it to another location, went in for about 20 minutes, came out and it took 2 tries to start the car. On the second try, I pushed the accelerator pedal about 1/3 of the way to the floor and she fired up. Any ideas?
3. Also, during the above starting scenario, while just observing the car from the outside, I noticed water droplets from FWD end of both mufflers. I figured the exhaust would of dried out after 3 hours of highway driving. Any clues?
4. A little history on this car. It has 67K, 1 owner and has most likely spent more time sitting the past few months than on the road. The car drives very smooth and runs like a scalded dog when the throttle is mashed to the floor board. The engine idle after warmed up is 1000-1200 RPM. Is this too high?
Thanks!
Jim White
