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1968 Pre-mach I Conversion, 351w

  • Thread starter Thread starter imp
  • Start date Start date Jul 14, 2017

imp

Mustang Master
Jul 13, 2017
531
105
83
Jul 14, 2017
#1
  • Jul 14, 2017
  • #1
Very strange outcome. Anyhow, I converted the car to EFI using Ford Motorsports parts intended to do just that. Ford used the same injectors, Mass Air Sensor, and computer (PCM) that was used in the 1993 Cobra 5.0HO, 24lb. injectors, and supplied the GT-40 Lower & Upper Intake Manifolds. Finished job looked like this:



Got her running, seemed very strong and smooth. But, I wasn't happy with the starting: engine cranked way too long before firing, cold or hot. Unsure of how to proceed, but knowing that after having brought the guy's car to my shop in Phoenix all the way from Albuquerque, I had to give him more acceptable results. By chance, I had at the time a great-running '93 Cobra which I had repaired front end damage on, with express agreement with my wife that if we bought the Cobra, it would become HER car! So, it was.

On a hunch, I yanked the PCM out of the Cobra, installed it in the Mach-I, and, sure enough, it started instantly, just as the Cobra had. Even bigger hunch, I put the bum-starting PCM in the Cobra, turned it over, and it fired up immediately! And so they remained in place, the Mustang owner flew in from Albuq., paid the rest of the dough, and drove it home with his son. I had asked him to call me, let me know how it ran. He did, they were pleased as could be!

The Cobra still has that same PCM, and resides in Topeka, KS, owned by my Nephew! I have no idea what transpired with those computers! imp
 

Rusty67

20+ Year Stangneter
Dec 3, 2002
3,749
37
109
LA, CA
Jul 15, 2017
#2
  • Jul 15, 2017
  • #2
What I'm guessing is that the ECU connector wasn't making good contact and when you switched them you fixed the problem.
 

imp

Mustang Master
Jul 13, 2017
531
105
83
Jul 15, 2017
#3
  • Jul 15, 2017
  • #3
Rusty67 said:
What I'm guessing is that the ECU connector wasn't making good contact and when you switched them you fixed the problem.
Click to expand...
It's a thought. Car ran very well, though, once it started. imp
 
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