6G Celicas Forums

Three months ago my 1994 Celica started missing in first gear. The more gas I gave it, it felt like it was bogging down. It was also stuttering, and I thought I got some bad gas or too much ethanol in the car, so I got injector cleaner, put in some high octane gas, and it got a little better. Then it got worse again so I replaced my fuel pump, my fuel filter, my MAP sensor, my TPS, and my Cooling Temperature Sensor. I put a vacuum gauge on the EGR while the car was idling, and the car stalled out, which tells me the EGR is working ok. I removed the EGR, cleaned it, removed my throttle body and cleaned it, and it has improved. It accellerates fine without missing, it will miss so once in a while at high speed, but when idling it will miss, and it acts like it wants to shut down, but then it revvs up and it does this several times before actually shutting down. The only other thing that I am working on now is the IAC. I removed the IAC and tested it by applying 12 V to B+ and the ISCO and the little valve opened. Next, I applied voltage to B+ the ISCC and the valve went to close but did not fully close. After I removed the voltage, the valve went to a default position about midway/ half open. Is the IAC functioning properly when it does this?
I do not know what to try next if it is not the IAC. Please help.

try cleaning it up really well. did you do spark plugs && wires. that wouldve been one of my first steps..

wires fairly new, but plugs are new. do you know anything about IAC?

sounds like spark plug wires, mine did that it was 1st gear bogged down and sounded ****ty, replaced that and tada brand spanking new.

i may try the dist cap as well, the idea of putting in more money at something, when you are not sure if it will fix it. more so when there isn't much money to do it with!!

Here....right out of the good book.
Connect pos (+) lead from the battery to terminal +B and neg (-) to terminal ISCC, and check that the valve is closed.
Connect the pos (+) lead from the battery to terminal +B and neg (-) lead to terminal ISCO, and check that the valve is open.
If operation is not as specified, replace the IAC valve.

Its supposed to fully close, when you apply the volts to +B and ISCC, not "a little closed".
I say disassemble the IAC, and clean it up good, then retest.

Thanks, i did take it appart and cleaned it. it closed a lettle more,but not all the way. Thats a $233.00 part but, it is what it is!!