I'm having a problem with my temperature gauge. The problem is that it always takes at least 45 minutes of driving before the gauge reads anything at all. Of course the car is always warmed up well before that. I think this is also causing the problem with the high idle as the ECM is always thinking that the engine is cold and revving it up. What could be causing this really slow temp reading ? Bad temp sender in the corner of the head ? Faulty thermostat ? This is on my newly rebuilt 2.8 which otherwise runs great. Once I finally get a temperature reading from the gauge the idle drops down to a normal 1K or so. I normally get warm air after about 5 minutes or so in my other fiero with the same engine. Not with this one, which is why I' m thinking it might be the thermostat.

Think you answered you own question. If both the engine and gauge are acting the same then have to guess BOTH senders are working correct.

If it takes that long to warm up you gas mileage can't be to good either.

Yes a bad stat can do that. They can float open and not let the engine warm up fast enough. If you test it in a pan I bet it will test good, but if you replace it bet your problem will be resolved. Had it happen twice on mine.

quote Originally posted by Dodgerunner: Think you answered you own question. If both the engine and gauge are acting the same then have to guess BOTH senders are working correct. If it takes that long to warm up you gas mileage can't be to good either. Yes a bad stat can do that. They can float open and not let the engine warm up fast enough. If you test it in a pan I bet it will test good, but if you replace it bet your problem will be resolved. Had it happen twice on mine.

Yeah it did turn out to be the thermostat, everythings working fine now. Thanks for the reply