Engine Performance problem
1998 Mazda Protege 4 cyl Front Wheel Drive Manual 186000 miles
This is a strange problem. I have had constant rough idle troubles with this vehicle. I have cleaned out and tested the EGR, IAC, throttle body, etc. This has greatly improved idle, however it still idles rough under the following conditions:
Closed loop operation with the brake light switch closed. Ie: If the engine is warm and I press the brakes, the idle drops from 700 to 200. If I press the brake pedal and unplug the brake light switch the idle returns to normal. (This seems to eliminate the possibility of a vacuum leak at the brake booster). If the engine is cold it idles normally. If I disconnect the brake light switch it idles normally when warm. Does my computer have a problem or need to be reprogrammed? Does the TPS require adjustment? Thank you!
have the same problem?
Monday, December 29th, 2008 AT 9:19 AM