My 89 F150 w/ 5.0 has started stalling everytime I come to a stop or slow down. The engine dies right at the moment the A/T downshifts (around 10 mph). The engine dies even if I shift to N before slowing down. I think the idle speed is too low. Could this be timing? This has been happening intermittently for several weeks and I did not get any codes, just "system pass". Now that it is doing it all the time, I will try to pull codes again. Any thoughts/help would be appreciated.

 

Could be a sticking idle speed control motor, or the EGR valve could be sticking open.

-Jon

 

I cleaned out the idle air control valve and that helped a lot. Thanks. I also have a miss at low rpm/speeds when the engine is warm. Doesn't seem to be a problem when engine is warming up. I do not get any code so I don't think it is a TPS problem. Timing is okay. Will check plugs for gap this weekend. Is there a way to tell if spark plug wires need replacing? Mine are original.

 

you can have someone put it on a scope or use an ohm meter to check the wires....but if they are original on a 15 year old truck i would replace them without question. May not be your entire problem but it could definitely be a factor. what about cap and rotor? ......please don't say they are original too.. :-)

 

No, the cap and rotor are not original but they were changed along with plugs about 7500 miles back. I will check them and clean up the contacts. I will installnew wires. The problem is not noticeable when engine is warming up--gets worse as engine heats up. I have heard that a coil can have a problem when it heats up so I guess I'll change that too. Coil is OEM. Will advise.Thanks for the reply.