I still have no spark after installing a new coil, TFE on distributor, fuel pump relay?

RANDY ISBILL

MEMBER
1986 FORD F-150
5.0L
V8
2WD
AUTOMATIC
140,000 MILES

For starters, I installed a new coil, TFE on distributor, fuel pump relay, and I still have no spark. The fuel pump relay will not pull in nor will the EEC relay. Turn the key on no fuel pumps no injector power but jump out FPR and the pumps come on but, still nothing else. I get one spark when I let go of the key, I have 12v to the coil, rotor turns. Next for me is a new distributor or EEC, maybe. I'm confounded

5 Replies

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

There is a wht/ltblu wire going to the EEC relay. When the key is on it should have power. It sounds like the ignition switch is bad if you don't get power. Here is a guide to help and the location of the EEC relay:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the images (below). Please let us know what happens.

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Wednesday, January 3rd, 2024 AT 10:10 AM

RANDY ISBILL

MEMBER
3 POSTS

Well, the EEC relay pulls in, the DK BL has no power going out because its burnt in2. So I chased the wiring from the fuel relay and low and behold found a red one with no insulation on it for about 4 inches, it was arcing to the valve cover, so now I need to find a under the hood diagram before I go any further. Thanks for guiding me to the relay, it helped a ton.

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Friday, January 5th, 2024 AT 4:21 PM

KEN L

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Sure, here you go, and I have included a guide to help with the testing as well.

https://www.2carpros.com/articles/how-to-check-wiring

Check out the images (below). Please let us know what happens.

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Sunday, January 7th, 2024 AT 10:00 AM

RANDY ISBILL

MEMBER
3 POSTS

The wire to the EEC relay was broken inside the jacket, repaired it. Found several burnt wires in the harness under the hood, replaced those. My fuel pumps work now, I have very good spark, have good fuel pressure in the rail but I also have 12.1VDC on both wires on all injectors. I unplugged each one and checked them to ground and both had 12 volts. How does that happen?

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Thursday, March 28th, 2024 AT 6:35 PM

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

To confirm all of the injectors are unplugged when testing, correct? The engine computer grounds the injector for its operation. If any of the injectors are still plugged in this will happen. Please let me know.