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jcgarcia8318 05-28-2014 10:08 AM

Mustang dies while running no symptoms
So i have a 93 Mustang lx fox body with a 5.0 swap. while driving it just kills over. i still have battery power but no spark to run motor. its happened multiple times over the past week. It will start back up after time of cooling. over the weekend i replaced the tdi and thought it was solved. checked ground and power wiring all is fine. Confused and at a loss hellllllllp my pony!!!! Pcm failure? pick up gone bad? what?

yurizx6r 05-28-2014 12:57 PM

Does the voltage meter go up and down or does it just die? That happened to me this weekend, but it turned out to be my HID ballast shorting out, and was pulling so much power it stalled my motor!

AMWill 05-28-2014 01:03 PM

I just recently had similar issues with my cousin's '95 GT too. We confirmed both the battery and the alternator were good and didn't find any shorts. That's when we started looking at the ignition components and found the coil was going bad. Once the coil got hot after running for a while it would intermittently fail. After replacing the coil, the car has been running strong!

I know it's rare for the coil to fail intermittently, but it's still something you may want to check. Hope this helps!


jcgarcia8318 05-28-2014 02:05 PM

I have a msd coil pack and it seems to be working fine. I'm at a complete loss.

yurizx6r 05-28-2014 07:42 PM

Could certainly be a bad TFI module. But if it is not, are you sure it's spark and not your fuel pump?

88 orangepeel notch 05-29-2014 07:56 AM

+1 ^^^

We need to know for sure which is missing, spark or fuel ?

jcgarcia8318 05-30-2014 08:21 AM

I'm pretty sure I'm getting fuel I hear the pump kick on but haven't looked at the injectors. I do have a msd control box and spark coil.this problem happens intermittently more now since irs getting hotter out. After it cools it sometimes won't start back unless I take the plug wire from the coil going to the distributer and sorta jump a spark to get spark flowing again. Hope this makes sense all.

88 orangepeel notch 05-30-2014 10:18 AM

It sounds like the classic TFI module going bad and I know you just replaced it, but maybe pull it off and get it tested at Autozone, Advance, O'Reily, whatever chain you use. Have them test it 3 times so it gets hot. New parts don't always mean good parts. Just an idea and it's free.

yurizx6r 05-30-2014 11:41 AM

Let us know what you find out. I'm putting my money on the TFI module. If it's the stock one, upgrade it and get an MSD one anyways. Couldn't hurt either way. Even it that isn't the issue, you can at least rule it out.

jcgarcia8318 06-01-2014 10:22 AM

Still no go guys

88 orangepeel notch 06-03-2014 02:55 PM

I'm assuming that the TFI tested good, then dig around on the forum for a step by step walk thru on a "no start". If I find it I'll post the link. It walks you thru on diagnosing your problem is. It helped me a couple times.

88 orangepeel notch 06-03-2014 02:59 PM

Found it,5...1.html#msg6501

jcgarcia8318 06-08-2014 08:00 PM

Still no go will drive for about 20 30 min then it just kills over

mjr46 06-09-2014 09:47 AM

by the time you take a tfi off, bring it to the parts store for testing, it'll cool down and of course test good.......other possible things = stator in the dizzy

88 orangepeel notch 06-09-2014 09:55 AM


Originally Posted by jcgarcia8318 (Post 8396451)
Still no go will drive for about 20 30 min then it just kills over

Did you get the TFI tested ? Like mjr said a cold one may test good, Have them run the test 3 times, in a row. It'll be very hot by the end of the third test. That's where a bad one will fail.

jcgarcia8318 06-10-2014 07:40 AM

I'll let you guys know the status of the tdi on Sunday. But if there's any more ideas I'll be glad to try them out.

88 orangepeel notch 06-10-2014 08:14 AM

Just out of curiosity, when the car dies, feel your fuel pump relay. Let me know if its hot. It might not be nothing but my car happened to just die on the road at speed this week, only for a second or two, then start back up by itself and motor on like nothing happened. When I got home, I pulled my ECM and harness out of the kick panel while the car was running and it hiccuped again. So I thought lose wire but I couldn't get it to do it again no matter how hard I pulled on the wires, lol. But I did notice my fuel pump relay was very warm to the touch. I also was almost on empty so I filled the tank and the relay stayed much cooler. Maybe my fuel pump got hot, I don't know as I'm still tinkering, but just an idea.

Wrenchman1 06-11-2014 12:41 AM

You stated that you pulled the coil wire and got the spark going again? 1st check the engine ground. Don't just look at it , clean it. 2nd I had an engine that would run with a spark tester in line with the coil but not direct. The coil wire was bad. as had a poor ground also. Just a thought

mongolchuck 06-11-2014 05:45 PM

Msd boxes and coils do this occasionally, seemingly more often than stock. I'd throw the stock ignition components back on and see what happens.

Wrenchman1 06-12-2014 07:14 AM

OEM if ya can, I was wondering who makes FRPP ignition box and coil.
I have an MSD on the 5.0 , That's the way it came TBH, I don't trust em.
Open it up and look at the components, JMHO.
Trying to find out if the FRPP unit is any better.
Im sure the Race teams get stuff ya cant buy.
Random Thoughts.
I have had a lot of issues over the years with aftermarket, Wires, HEI Modules
Crappy points and condensors. Ya Im that Old!

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