sod_nicholls

My girlfriend has a 2000 prism(corolla) and there is a problem we have not been able to figure out.
With a cold engine starting in first gear, the engine does not respond to the open throttle. It almost seemed like the cable from the pedal to the throttle was loose but this checked out fine. The problem comes and goes...sometimes the car accelerates just fine. Sometimes it hesitates for only a second before quickly surging to the proper rpm's for that position, other times she will have to drive around a parking lot to get it to stop sticking.
It seems like it could be a sensor, possibly the tps? Throttle seems to have no problems as the engine will stumble at WOT because of a lean condition. Seems like the injectors just arent being told to dump fuel into the cylinders when the throttle is pushed down. Anybody have any ideas? From looking at the engine, I think the tps is connected to the cable that gets pulled by the throttle and runs down near the transmission.

zze131

I suggest cleaning the throttle body on the car as step 1. Afterwards, check and see if the MAF sensor element is dirty as well as step 2. (Do NOT touch the element itself!).

sod_nicholls

The dirty MAF element was the ticket. I figured this was the case since it mainly had the problem in open loop (cold start).
We pulled the MAF sensor and used a q-tip with isopropyl alcohol solution to carefully clean the two wires. Actually stumbled upon cleaning instructions for this sensor with pictures on a lexus owners club site: http://www.lexusownersclub.co.uk/kno...x_v2&id=50&c=9
The part is identical though the airbox is not. We also cleaned the IAT sensor which is the more visible one on the side.