Car shut of while driving on hiway

Creomod

5 Year Member
Sep 14, 2018
525
42
48
San Antonio,Texas
Ok guys I swapped out my alternator from my other car yesterday because I kept getting the battery symbol while driving. But I didn’t have problems. The light went away. So I thought everything ok . Just right now I was at my friends house and decided to go home . Car wouldn’t start. Looked at everything and nothing looked out the ordinary. Kept cranking car finally started. Drove fast going home on hiway and the car shut off going 80 lights on everything stayed on then it kicked back on. Did it twice. What would cause that? Ran codes did get a 54 but I don’t think that would cause that. Any input much appreciated……
Ran codes 18,31,85 also used noid light on injector blinking. Also used inline spark tester hooked it up on coil and it lit up so I have spark and noid light blinking so distributor good? Maybe the alternator causing car to shut off? Used different fuel relays does same thing. I am getting fuel pressure at 40 something when on
 
Last edited:
TFI Module 100% cooked ,

get this TFI tester to test your current one from eBay works amazing and don't forget to buy a 9volt battery.


Then if needed buy a new TFI Module from Rockauto.

Motorcraft TFI
https://www.rockauto.com/en/moreinfo.php?pk=5434788&cc=1134010&pt=7172&jsn=17

STANDARD MOTOR PRODUCTS LX223 TFI for Manual 5 Speed Transmission.

and you can relocate your new TFI module with this, best one out there.
https://www.mccullyracingmotors.com/

get some extra Arctic Silver 5 thermal paste
https://www.ebay.ca/itm/16642480345...pid=5335821607&customid=&toolid=10001&mkevt=1

and after its all installed your stang will fire right up and drive beautifully.

also if you ever need your ECU repaired this place is awesome and the best place to get it fixed at.

www.theecuexchange.com

1986-2004 Ford Mustang A9L A9P ECU Repair Service

1986-2004 Ford Mustang A9L A9P ECU Repair Service Engine Computer Repair Please fill out the R&R form here once you've placed your order.Easy repair process1. Purchase repair service (this way helps us keep track of what's coming in for repair)2. Include order number with your computer and mail...
www.theecuexchange.com
www.theecuexchange.com
 
Last edited:
  • Like
Reactions: Creomod
TFI Module 100% cooked ,

get this TFI tester to test your current one from eBay works amazing and don't forget to buy a 9volt battery.


Then if needed buy a new TFI Module from Rockauto.

Motorcraft TFI
https://www.rockauto.com/en/moreinfo.php?pk=5434788&cc=1134010&pt=7172&jsn=17

STANDARD MOTOR PRODUCTS LX223 TFI for Manual 5 Speed Transmission.

and you can relocate your new TFI module with this, best one out there.
https://www.mccullyracingmotors.com/

get some extra Arctic Silver 5 thermal paste
https://www.ebay.ca/itm/16642480345...pid=5335821607&customid=&toolid=10001&mkevt=1

and after its all installed your stang will fire right up and drive beautifully.

also if you ever need your ECU repaired this place is awesome and the best place to get it fixed at.

www.theecuexchange.com

1986-2004 Ford Mustang A9L A9P ECU Repair Service

1986-2004 Ford Mustang A9L A9P ECU Repair Service Engine Computer Repair Please fill out the R&R form here once you've placed your order.Easy repair process1. Purchase repair service (this way helps us keep track of what's coming in for repair)2. Include order number with your computer and mail...
www.theecuexchange.com
www.theecuexchange.com
Hey brother I just bought that tfi tester you sent me from eBay. Do I have to remove the tfi or can it be tested installed? Dose t say anything on discption
 
Hey brother I just bought that tfi tester you sent me from eBay. Do I have to remove the tfi or can it be tested installed? Dose t say anything on discption
Actually you have to unplug the tfi from the distributor because you need to probe the 3rd prong you will see in the instructions. Don't forget to buy a 9volt battery.
 
  • Like
Reactions: Creomod
Update! I removed the alternator to have it tested & it failed. I know we are thinking it might be the tfi/distributor wondering if it was the alternator reason why it didn’t want to start then shut off on hiway & then kicked back on again?
 

Attachments

  • IMG_1502.webp
    IMG_1502.webp
    214.6 KB · Views: 102
I just swapped to a different distributor still wants to stumble shut off. I checked coil has light both sides key on. I’m gonna swap the fuel regulator see if that helps. I also have had a raw fuel smell while driving. I removed the vacuum hose off the regulator don’t see fuel. Only other thing I can think of is ignition switch or fp.By the way the distbutor in my hand I just removed it and that’s the one that car was shutting off with and backfired on me this morning
 

Attachments

  • IMG_1515.webp
    IMG_1515.webp
    241.3 KB · Views: 242
Check the computer ground by battery. A bad fuel pump relay or pump can cause cut off issues but not common to fail that way. TFI usually has to sit and cool down before restarting. If your coil is shorting you should be able to see it in the dark reving engine. Sometimes you can see spark jump. Usually, will cause weak spark or no spark. I'd ohms test the coil and clean all the ground connections. I'd also check the ignition switch wires and switch body for looseness or overheated contacts.
 
  • Like
Reactions: Creomod and 2000xp8
Check the computer ground by battery. A bad fuel pump relay or pump can cause cut off issues but not common to fail that way. TFI usually has to sit and cool down before restarting. If your coil is shorting you should be able to see it in the dark reving engine. Sometimes you can see spark jump. Usually, will cause weak spark or no spark. I'd ohms test the coil and clean all the ground connections. I'd also check the ignition switch wires and switch body for looseness or overheated contacts.
How can I see it in the dark for the coil? What is spark jump? Fuel relay I bought 2 weeks ago along with o2 sensors.ignition switch was swapped about 6 months back along with sp wires. Now one thing I will say o know car running lean cuz I see it on the plugs and I have been driving with bad afr gauge sensor but not sure if that’s why it’s cutting off and that’s why I was suspecting the fuel pressure regulator
 
I'm inclined to think it's a connector or loose wire/ground somewhere also.
Probably not going to be fun to track down.

The reality is that it would be easier to fix if it was plain old broken.