Wont start after being driven

[mustang2514]

Just picked up a 91 LX, if I take it basically around the block and get it to operating temp when I turn it off it will not fire back up on its own for about an hour, at least. I can jump it to bypass all that waiting time. Car has GT40P heads, comp cam, trick flow intake, longtubes, 75 shot zex, 30lb injectors, electric fan, 6al box, moates chip, and that's about it. Alternator appears to be stock, I was thinking maybe upgrading that might help. I just don't want to part change, hoping maybe someone has had a similar problem and can help me out.

[vertigo]

Is the ignition box getting heat soaked?

[mustang8998]

You say you can jump it and it starts? So, it won't crank once it's warm, or it will crank and not start?

Starters don't like all that heat, especially with long tubes. Might try wrapping some of that heat shield mesh around the starter.

[slow86fiveoh]

My 87 done something similar to that before the pickup went out of the distributor, installed a new dizzy and was fine after that, also as stated above msd 6al boxes dont have the greatest track record

[mustang2514]

It will crank but it is very weak and just gets weaker. I wrapped the starter last week, so I don't think that was the problem. The ignition box is in the cowl vent area so I think it is staying cool. I will have to check out the distributor. Thanks for your guys input thus far.

[chris91]

I'd say it's the alternator if it starts when you jump it. Pull it off and have it tested.

[timdsellers]

Yep, had the same issue and it was the pickup coil in the dizzy. Seems like if it was the alternator it would just be still dead an hour later.

[Stangman]

Get rid of that stock massive inefficient foxbody starter... swap it w/ a 94/95 5.0 starter. Also the same starter from 93 Cobra's, and any 5.0 Ford Explorer/Mercury Mountaineer. You'll have to flip flop some connections at the starter solenoid on the fender but it will be MUCH better!

[facemelter71]

Just for shits and giggles,have you traced the grounds for the starter and engine? Make sure all the cables are good and dont have the GFS (green fuzzy stuff) on them?

[timdsellers]

So is it not cranking long enough to start before it dies or just turning over too slow? Or is it turning over well enough but not firing? Need to know if its an actual starter issue or a firing issue.

[mustang2514]

It turns over to slow and gets weaker with every attempt until it just doesn't want to do anything. At this point I can walk away, come back a little later after it is cooled downed and fire it right up. But like I said, I can jump it off my other car and it fires up. It needs tuned and is going on Monday, im gonna switch out the dizzy for the tune and see if it is the pickup.

[Stangman]

crappy battery... crappy stock foxbody giant bulky starter.... which gets heat soaked. Gear reduction unit is the only way to go.

Starter gets too hot/overworked and it takes much more battery draw to make it turn. a newer style starter doesnt need as much draw. been there done that.

[mustang2514]

Had the car tuned today and it will know start after being run, still a little weak but starts. New starter is on the to do list though, thanks for the input guys.

[Rick93coupe]

Theres a bunch of them out there but Ive had great luck with the CVR starters.