I have a 91 305TPI engine (stock) what temp is normal for this engine? It looks like the fans turn on at 225 and turn off at 218. I was thinking of having the prom programmed to have the fans turn on sooner and run longer but I was wondering if any one had any input on this.

Thanks
Mike

 

Get a 180/160 t-stat and matching fan switch. Easier/cheaper than rooting around in the prom if you do not have the software to do so.

 

I thought i read the cooler t-stats require changes in the prom, What is the normal operating temp for this engine?

 

I wouldn't use a 160* anything in a TPI. IIRC it doesn't go into closed loop mode until 180*. They do make replacement fan temperature switches like mentioned. If you're having cooling issues I would first check the Air Dam under the radiator and then see what the coolant looks like.

 

Stock 305 has a 195 thermostat. So it is fully open at about 200. 160 is too cold for correct engine operation and maximum power. You want decent heat in the engine AND you want COLD air into the throttle body. That is when you get the most power. The whole point is to have CONTROLLED engine temps, not too cold or too hot. Your cooling system should be able to maintain the engine at 195 or below or you have water or air flow problems.

Generally, water flow issues show up at speed (vehicle moving) and air flow issues show up at idle (vehicle stopped). If your car idles and does not get hot, then overheats at road speed, you have a water flow or radiator capacity issue. If, on the other hand, your car gets hot if you sit and idle, then it cools off as soon as you begin to drive then you have an air flow issue.

All things being correct, the cooling fans should cycle and maintain temps about 210-220 on a stock vehicle. Rolling down the road, you should be seeing 195-200 solid as a rock without fans.

 

92 FSM states closed loop occurs at approx 155.