So a notice came in the mail a while ago telling me my car needs to be smogged. So I took it into a smog station and it failed... miserably. The one part I didn't expect was to see a report on the sheet that my timing was off by 6 degrees at 18 degrees BTDC.

I took my car into my local shop after I was not able to duplicate the problem at home. (I also needed my catalic converter replaced)

The mechanic hooked up his timing light... and it was PERFECT... right on 12 degrees BTDC. He drove it into the shop (no more than 20 feet) to put it up on the lfit and it was back to 18 BTDC.

Infuriating. After spending the better half of the afternoon diagnosing it with him, we learned that the problem was two-fold. First, the throttle position switch was intermittantly not working.

The second cause suprised me. Apparently the plugs for the throttle sensor and the idle sensor are the same size and shape. If you reverse the plugs, it causes the ECU to have a glitch each time it is powered up--but the first time the gas it hit, even momentarily, the glitch dissapears. The only thing the glitch causes is a 6 degree advance in the timing. Start the car, the timing is 6 degrees retarded. Hit the gas, timing is normal, and will stay normal, even at idle, until the car is turned off and re-started.

Anyone ever heard of this kind of thing before? Anyone know of a work-around that would allow the timing to remain stable regardless of starts / stops?

Thanks,

-Flup

PS - DON'T SWITCH THE PLUGS FROM THE IDLE SENOR AND THROTTLE POSITION SENSOR OR YOU TOO WILL EXPERIENCE THIS PROBLEM!