I have a 93 ford f 150 with a 302. I had the motor rebuilt and converted it to mass air. My problem is that when I start the truck the check engine light stays on and it idols real low. Wonce the light shuts off, it will high idol like a normal vehicle and run fine. The biggest problem is that after the truck is warmed up the only way to start it is to hold the pedal to the floor. I replaced filters, plugs, wires, and other little things but I think it might be a sensor or something stupid. Any help would be great. Thanks matt

. Check for codes. AutoZone will do this for free. The answer likely lies here.

. Check the Ignition Control Module (ICM) and coil. AutoZone can test many ICMs and coils for free.

Did you use Motorcraft spark plugs?
Did you replace the fuel and air filter?

Autozone says they can't check the codes on a 93. Motorcraft spark plugs were used. It also has a new air filter and new fuel filter.

Yes, you are right--AutoZone can only check for codes on OBD-II vehicles (1996+). You need to find out how to check for codes on your truck. There's likely a Service Check Connector that needs to be jumped.