Mustang Start Problem

[apache41]

I have and am currently been fighting a problem with my 1991 5.0 Liter Mustang Convertible relating to a start problem.. I have finished back last sprint restoring my mustang from ground up. I will have the mods listed below. I know it isnt a hot start issue because the starters arent that close to the header not to mention that I have used heat wrap and bought a new starter and still the same problem.. I have also verified my timing via standard timing light method but also total timing using the computer which is supposed to be base timing plus the 20 degree advance used during the test +/- 3 degrees which should be around 28-32 degrees and mine was 29 degrees total and 14 degrees standard timing check.. THe funny thing is I can start the car and let it run in place all day and never have a problem but if I drive the car and turn it off and go to start it back up it turns over real slow and the just stops.. I have fried the little black lead wire coming from the negative battery cable going to the fender well twice.. If I let it sit for about 20 minutes it will start up with no problem.. I do know that the voltage gauge fluctuates sometimes when driving.. I have done a charging system check and get a 14.4V while running and 12.5V with the engine off.. The car is a beautiful car and I have it listed under mushang91 on cardomain but I am about to drive it over a cliff if I dont get this problem fixed soon.. Any info or help would be greatly appreciated.. I usually have been pretty good trying to locate and fix problems but this one has got me stumped.. Thanks Again..

302 bored .020 over
E303 cam
Crane 1.6 Gold Extruded Aluminum Roller Rockers
Mac Header and Exhaust
Mac Cold air induction
PA Performance 95 amp alternator
Ford Racing Underdrive pulleys
Jegs Performance Coil
Mallory 8mm plug wires **NOW**
Edelbrock Performer Intake upper and lower
Mallory fuel pressure regulator
etc.

[Mr 5 0]

You have a 15-year-old Mustang and even with low mileage some things just go bad from age, rot, corrosion, etc. This may be one of those instances.

Assuming your battery is fresh and not compromised or undersized, you might want to try investing in new battery cables (negative and positive) as well as checking your ground for a bad connection. I would also replace the TFI module, which I suspect may be the real culprit.

[apache41]

Thanks for the info.. I though the TFI would cause a stall condition while driving once it got hot but what to heck it is worth the try. I am kinda thinking one of the cables could be causing me an issue or a ground is bad since I am burning up a small ground piggy backed on the negative battery cable.. Its almost like it isnt making a good enough ground and trying to use the other path.. But then again why would this only be the issue when driving.. Oh well I will try all of the above as I am sure they need replacing anyway and we will see what happens.. Again Thanks a Bunch!!!

[okiedragster]

Next time when it is hot and you can tell when you hit the starter that its not gonna crank, pop the hood and disconnect the ignition via coil wire or what ever just as long as its not getting fire. jump in and see if it will turn over any easier, this is a easy way to tell if your having timing issues. i have a 36 degree advance curve in my super comp dragster and i have to get the motor turnin first and then switch on the ignition switch and it will bust right off. with the crap gas we have to run these days and puttin advance timing in it will sometimes throw us a curve on hot starts, but boy does the car run good ...lol . just somethin to try. i have a hidden switch under the dash on my 71 mach1 that cuts the hot side of the coil because ive had it happen on it from time to time after driving in slow traffic ect. the battery cables is a good prospect too if a cable gets hot a few times it will corrode from the inside making it hard to tell it bad because it may look brand new but it knocking the voltage down just enough to get a hot start... hope i have helped ya in some way...