we have been trying to get this 91 RS we have had for 3 years now to crank. I drove it when i was a senior in high school 2 years ago and it ran great. We let it set for a while and now it wont crank. all the plugs and everything are in good shape on it. new alternator and battery. i am thinking maybe a fuel filter or pump but when you turn the switch you can here it come on ???? have any ideas guys?

 

Hmmm, did you start with the obvious battery. Maybe it's still got juice but not enough to spin that motor.

 

Will it turn over? If so, I suggest Fuel Filter, and also drain the gas and add some fresh gas. If it won't turn over, check ALL the connections to the battery and starter, and also check that your Security light isn't staying on. That would be a sign of either a faulty/worn out resistor in your key, or a fault somewhere in the VATS system.

 

just make sure the engine is getting fuel to it before you go any farther , if it is turning over that is.

 

ok...a few questions.
Can the engine turn over(crank) at all?. If not try to turn by hand(socket) If not remove heads and soak in PBblaster to remove rust.
If the engine does turn but not start, check the fuel pressure. There should be a fitting to put on a guage. If the pressure is low, obvious fuel pump. It's a Biatch to do.
Spark is easy to check...air is obvious... Just remember there are three things needed for fire. Go by that therom and you'll find the prob. One thing that is really overlooked for spark is the control module inside the distributor.