Engine Performance problem
1988 Toyota Pickup 4 cyl Two Wheel Drive Automatic 44000 miles
22REC engine (Calif), 1-ton
I replaced O2 sensor because I was not getting a good reading then I noticed it appears O2 sensor heater is not being activated. HT pin on ECU is used to ground heater circuit, but is staying high. If I manually ground this pin I get about 1amp, which seems right.
Q: Should this heater be turned on as soon as engine starts, or are there other conditions that gate it? Is this a burned out ECU?
When warm idles poorly, almosts stalls when put into gear. Failed smog due to high HC. Power seems low. Smooth acceleration, but not very quick. Revs up high eventually fine. Freeway speed is no problem. Starts fine.
Added an air leak and that made it worse, so it seems like it is running lean. Haven't found air or exhaust leak. Idle speed air bypass screw is turned out almost all the way to get idle when warm.
Wednesday, August 4th, 2010 AT 4:40 PM