starts, doesn't start

[wd21921]

92 F150 5.0L engine starts but after it does and you shut it off, it doesn't seem to want to restart. It will start again after it has been shut off for about 2 hours or more. Any ideas?

 

[Skandocious]

Sometimes a tfi sensor will exhibit this behavior because of heat. Do you have a distributor-mounted tfi module?

 

[wd21921]

tfi is not on top of the distributor

 

[smokey]

Does it turn over after shutters it off?
Does the starter sound weak after running.

 

[wd21921]

the engine turns over but it does not fire up; starter does not sound weak either. I will try to clean the throttle body, then probably check the tfi module if that does not work. any other thoughts?

 

[O'Rattlecan]

There's a questionable ground wire that attaches on the starter that is intermittent. it sounds like your problem is heat related though so I'm not sure if that's the problem. It used to be a blade style connection but on the new starters you buy they are crimped.

Ryan

 

[Skandocious]

tfi is not on top of the distributor

it wouldn't be mounted to the top, but rather the side.

There's a questionable ground wire that attaches on the starter that is intermittent. it sounds like your problem is heat related though so I'm not sure if that's the problem. It used to be a blade style connection but on the new starters you buy they are crimped.

Ryan

If it were a starter problem then it wouldn't crank.

 

[O'Rattlecan]

Guess I didn't see it was cranking.

Ryan

 

[smokey]

I agree with Chris sure sounds like the tfi is breaking down when warm.

 

[wd21921]

another mechanic told me to replace the distributor and the tfi module at the same time. thoughts anyone? what do you think of used distributors? thanks in advance.

 

[smokey]

Why replace the distributor if only the tfi is bad. Throwing good money away replacing parts that are working.

 

[Skandocious]

Why replace the distributor if only the tfi is bad. Throwing good money away replacing parts that are working.

Replace 1 part at a time so you can avoid wasting money replacing good parts. Start with that TFI module as I suggested.

Is it distributor-mounted after all?

 

[wd21921]

I will replace the TFI module then, found some on ebay. And no, my TFI module is mounted on the fender. Thanks for the info guys. I will update as soon as it is replaced and tested.

 

[blacksnapon]

Partially sheared distributor gear pin, magnetic pickup in the distributor, debris in the oil pump pickup tube (admittedly rare but possible).

 

[wd21921]

Update: Replaced the TFI Module but it still did not work. Same issues, will not fire up when the engine is warmed up (Will start right away when cold). My plan is to replace the distributor with a used one. Any other ideas are appreciated. Thanks.

 

[Mil1ion]

If it is heat related it is not usually the dist

 

[Skandocious]

I almost wonder if the fuel pump relay is sticking...

 

[1970Custom]

I almost wonder if the fuel pump relay is sticking...

Can you hear the fuel pump when you first turn the key on during the no start period?

 

[Skandocious]

Can you hear the fuel pump when you first turn the key on during the no start period?

Good call-- that's a good thing to check here. When turning the key to the ON position (before you crank the engine), listen for the whine of the fuel pump priming. Also listen for the tone and make sure it doesn't sound different when the truck is warm.