No spark

Tiny
BIGGUY7180
  • MEMBER
  • 1994 FORD F-150
  • 5.8L
  • V8
  • 2WD
  • AUTOMATIC
  • 1,234,567,890 MILES
I have replaced the starter, the alternator, the distributor cap, rotor all relays, fuses, diode, the ignition coil and all three fuel pumps. However, when I go to turn it on and start it it only cranks and the fuel pump does not turn on. Also I tested it for spark and there is no spark. Now also when I go to plug in my code reader all it does is flash the screen and turns all my fuel pump. Any idea what my problem could possibly be?
Sunday, September 6th, 2020 AT 7:58 PM

3 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
The fact that you have no spark points me towards the crank sensor. Your vehicle doesn't have a traditional crank sensor, it uses a hall effect sensor in the distributor that picks up the rotation of the distributor and based on when it passes the windows in the rotary vane it can tell what position the engine is in. This is what the PCM fires the injectors and spark plugs off of. If the PCM is not getting this signal or the PCM is faulty it will not fire the plugs or injectors.

I would recommend replacing the switch and rotary vane and retest.

Let me know what questions you have. Thanks
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Sunday, September 6th, 2020 AT 8:12 PM
Tiny
BIGGUY7180
  • MEMBER
  • 2 POSTS
Thank you. I will try that.
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Monday, September 7th, 2020 AT 4:30 PM
Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
Sounds good. Keep us posted. Thanks for the update.
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Monday, September 7th, 2020 AT 7:57 PM

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