I have a '89 Formula 350 TPI and here is my scenario. Currently, I am in college so I don't get a chance to crank and start my car but about every 3-4 months. When I do crank it in these 3-4 months, it starts right up like a brand new car, but when I turn it off and try to start it again, it just cranks and don't start. So, I have to let the car sit for about an hour, then it will crank and start but only because of me spraying starting fluid in the throttle. I don't understand what's happening because if I let it sit for about a week or even the 3-4 months, it cranks and start like brand new. To give you the background of the car this is what has occurred: I bought the car from a guy who had it sitting for about a year and a half. It needed a motor. So I put a 350 motor from an '87 Chevy Truck (TBI) in it. I don't know if this could have something to do with it. Also, I was once told that it could be old gas in it, so I let the old gas run out, changed the fuel filter, and fuel pump relay ( and yes, the fuel pump does prime). The problem still occurs. So anyone, HELP.

 

Does it crank or not crank at all? Try putting a timing light on one of the plugs to see if the ignition module is working (putting out spark). If the module is not working than the injectors won't fire. Also try a noid light on the injectors. If you have both spark and fuel, you should look at your timing. If timing is correct, I would look at ground wires on the block and heads. Then maybe fuses.

 

It has no problem cranking (if you mean turning over). It just will not fire up at the stated times.

 

You need to go try the rest of my suggestions then. Can you take a log of what is happening?

 

Tibo, it will be a about 8 weeks until I can try your suggestions (seeing that I'm away in college), but when I do, I will keep a log and let you know the results. Thanks.

 

Check the resistance in the injectors, only takes 2 minutes to do. They should ohm out in the 14-16 ohm range. Any injectors out of this spec are bad, and need replaced. If they all ohm out ok, that still doesnt mean they aren't clogged.

 

If it is the injectors, what are the best kind to buy. (considering it is basically stock)?

 

It sounds like you have a bad Ignition control module. You can get it checked for free at autozone. It's located on the back of the distributor. Those are known for not letting you start your car after it has been warmed up.

 

Yes, ohm test the injectors. Forgot about that one. AutoZone can test the module, but their machines are not always 100%. I meant a log as in a datalog of the ecm. Using Win aldl or tunerpro.

Go to ebay and buy a set of used LT-1 injectors or ford motorsport injectors. Those can be had for dirt cheap. If you want new ones, buy ford motorsport injectors. Exactly the same as GM's, but at a lower price!