Vintage Mustang Forums banner

Struggling to get my 5.0 EFI running...

5K views 32 replies 13 participants last post by  bacchus203 
#1 ·
Finally got to a point where I could turn the key on my 5.0 conversion in my 66 Mustang. I had to cut it short as the day ran out, but unfortunately couldn’t get it to fire. Scratching my head a little, but wondering if anyone can suggest anything to try. I haven’t done a lot of troubleshooting yet but this is what I can confirm -
  • Turn to on and EEC relay clicks and primes the fuel pump.
  • Fuel arrives at the fuel rail (the one with the injectors attached which I believe is the supply during prime and crank
  • Starter engages during crank and turns engine
  • Pulling the main HT at the distributor I have spark firing
  • Can hear injectors ticking

I have checked and believe to have the correct 5.0 HO firing order. The injectors are connected in the right order.

Any ideas from anyone who has done this conversion? I feel like I have spark and fuel... so yeah, wrapped up today scratching my head a bit.

-Rob
 
See less See more
#30 ·
I cleaned and verified my injectors before installing them. At least verified they open and spray, not fuel quantity or pattern.
I bought a momentary contact foot pedal and added battery clamps on one side and an injector plug on the other. Pulled all the filters off the injectors, soaked them in carb cleaner, then pulled them out, hooked them up to the pedal and powered them up while blowing compressed air through them. new rings and filters.
 
#32 ·
A couple pointers.
1. Make sure it's timed correctly because the distributor also controls injector timing. So doing things like moving plug wires over 1 spot on the cap with no consequences on old cars isn't true.
2. I self tuned my car with a quarterhorse and it was always funky. I swapped to a megasquirt pnp ecm on my car and it drives so much better. I'm wondering if I had ecu problems with the ancient Ford computer. It took 3 ford ecus just to find a "good" one that worked .
3. If you have "calibrated" maf/injectors you might swap them for known good parts. I was running a 24lb c&l maf with 24lb injectors and the car wouldn't start. This was on a 351c I was putting efi on so I was sure it was something on my install. I finally decided to swap in stock maf/injectors and it hit on the first crank and purred. I tried 24lb stuff again and no luck, so I got a maf and injectors and the car ran great.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top