Is the cooling fan supposed to come on when you switch the key on?? Mine does not. I can only get it to come on when I am checking for codes, when I hook up my code tester. It is a 91 firebird 2.8L mpfi.

 

No, it's supposed to come on when the engine temperature exceeds 190* (IIRC) or the A/C is turned on. Some people wire the relay to the key switch to come on when the key is on, or put an inline switch to turn it on at will.

 

Oh, and its a 3.1 not a 2.8, sorry bout that. thanks for the info.

How do I check to see if it is working right? I had the car running today for about 20-30 mins, temp got about 200 then I guess the thermostat opened and the temp dropped back to 160. Fan never came on, even when I turned on the A/C. But like I said when I hook up my code tester it comes on.


NOW, I have another problem, the fuel pump quit working How hard is it to change the fuel pump?

 

the fans come on when the ECT reaches about 235 degrees. way too high, but thats what the ECM is set at. to lower that you can get a new switch, or just wire in a toggle switch. are you actually standing there looking under the hood, or just listening? start it up, let it run, and once it starts climbing, watch the fan. if you need to, put a flat head screwdriver in the throttle to hold the rpms up to warm it up quicker, like at 2k rpm.


are you sure its the fuel pump? turn the key to on (not crank) and see if you can hear it. next step is to get a fuel pressure gauge and check it while cranking.

 

thanks, got the fan problem solved. Now when i turn the key on I dont hear fuel pump, and I am not getting gas the bleed valve on the fuel rail. Could this be because of the oil saftey switch? It was low on oil when I had it running, then i switch the car off to fill oil, it wouldnt start back, just spin and spin. Still no gas to bleed valve. I was trying to check the relay, but cant figure out my wires. In the back of the car where the wires run to the pump, they are black/purple/gray...... I cant find these wires running to any of my relay's.