Hi,
I've got a 90 Tercel that's got a severe "dieseling" problem (engine tries to run despite the key being in the "engine off" position). The only thing unique is the fact that it *only* occurs at normal operating temperature, and the problem seems to be accompanied by acceleration-from-stop problems, specifically, the car accelerates very slowly in the lower gears and shakes like it's misfiring (again only at normal operating temp).
From what I understand, the usual suspects are:
*Carb choke/jet *Fuel cut solenoid valve *Incorrect ignition timingI tried to perform a timing check, but I can't adjust the idling speed down to 900 from 1100 (Toyota claims 900 is the maximum allowable speed for a timing check). Other than that, all vacuum lines (and there are LOTS of them) seem secure, the spark plugs are rich with fuel, the car gets lower than expected mpg, and it's very difficult to get the engine to turn over immediately after it diesels (though it will crank for a couple minutes before it finally turns over, probably due to cooling down from normal operating temp).
Any suggestions would be greatly appreciated, and I'll be watching this topic with great interest. Thanks! :)