Reader Question Hi.i own a 89 Toyota MR2 with a six cylinder 1G-GZE engine.it has a supercharger.it has 13000 km mileage.
My timing belt broke & had it replaced.while at the repair shop,mechanic also noticed the oil pump had seized.he replaced that too. when repair was done, afterwards engine would rev at nearly 3000rpm! It literally would drive itself while i strained to push brakes at traffic lights I’ve cleaned vacuum pipes& throttle to no avail. Please help!
First thing that comes to mind is a vacuum leak somewhere under the hood, or something is wrong with the idle air control motor……but most likely a vacuum leak.
With the engine running, I usually take a can of WD40 lubricant spray and slowly and lightly spray around gaskets and seals, sensors, fresh air intake hoses, pcv hoses etc. etc. and watch for an increase in engine RPM as the vacuum leak sucks in the WD40….which is flammable so it will cause the engine to increase in RPM.
CAUTION – WD40 is flammable, so if you spray it on a spark producing item….spark plug or spark plug wire etc. you will have a large fire!!!! Also super hot exhaust parts can ignite the WD 40, so make sure the engine is cold when you do this.
It is safer to use a bottle of propane and a rubber hose to dispense the propane around the suspect areas with pinpoint accuracy. You can buy or possibly rent one of these contraptions at your local auto part store.
I would also rule out the possibility of carbon build up inside your throttle body that might cause the air vane to stick or cause the throttle cable to stick or not fully release.