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Juan Crespo
Juan Crespo, Tech Trainer
Category: Ford
Satisfied Customers: 1494
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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I have a 92 F150 that is giving me fits on the fuel pumps. I

Customer Question

hi. my name is***** have a 92 F150 that is giving me fits on the fuel pumps. I have a manual and have already been checking several things. I know there is 12v to the fuel pump relay
JA: Thanks. Can you give me any more details about your issue?
Customer: hit enter by mistake lol. I have tested and can action the FPR. it has 12v on the coil side and the pumps will run if you ground the #6 test terminal to ground. I have continuity down to #22 at the PCM (EEC) which has just been replaced. any suggestions?
JA: OK got it. Last thing — Ford Mechanics generally expect a deposit of about $28 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 7 months ago.
Category: Ford
Expert:  Juan Crespo replied 7 months ago.

Hi there, TJ.

I can probably help you, but before I can even try to do so, I'd need you to answer a few questions for me:

  • What size engine are we working with?
  • Auto or stick trans?
  • 2 or 4WD?
  • Will the engine start and run if you ground the FPR?
Customer: replied 7 months ago.
HI. engine is a 4.9L 300 cid 6 cyl. automatic***** wont start at all. long story short, truck hasn't run in a year. have added fresh gas, replaced timing gears, ignition coil, map sensor, ignition module, cleaned and verified injectors are working and replaced the computer. old truck has a lot of sentimental value, but I'm about at wits end lol. I do have spark also
Customer: replied 7 months ago.
hold on!! I DID get it started so long as the relay stays jumped out it runs pretty decent!
Expert:  Juan Crespo replied 7 months ago.

But still no ground on the Light Blue/Orange wire from the EEC-IV computer to the FPR? Does the check engine light come on when the ignition switch is turned on?

Expert:  Juan Crespo replied 7 months ago.

Are you still there,TJ?

Customer: replied 7 months ago.
still here. no check engine light, no smoke, idle pretty smooth after not running for so long (probably remnants of old gas) but it will stall out if I remove the test ground wire. 12v comes to the FPR just fine IE ignition switch et all should be ok. ground wire from leaving side of FPR coil has continuity all the way to #22 on EEC/PCM but seems like it gets lost there or the EEC/PCM is not "seeing" that even possible?
Customer: replied 7 months ago.
after a 15 minute idle the check engine light did come on
Expert:  Juan Crespo replied 7 months ago.

OK. Turn ignition on and check for voltage at EEC/PCM pins 1, 37 and 57. Then check for ground at pins 20, 40 and 60. What do you have?

Customer: replied 7 months ago.
ok....with ignition on (engine off) pin 1 = 12.15v, pin 37 = 12.15v, pin 57 = 12.12v and there is ground at pins 20, 40 and 60
Expert:  Juan Crespo replied 7 months ago.

OK. That means external power and ground circuits for the EEC/PCM are good.

Now, I asked you whether or not the check engine light would come on when the ignition switch was turned on and you replied "no check engine light"; that fact, plus no ground to the FPR from pin #22, indicate at least those two logical circuits are bad within the EEC/PCM. So, before doing anything else, I recommend replacing the EEC/PCM first, then we can take it from there if necessary.

Expert:  Juan Crespo replied 6 months ago.

Hi again, TJ.

Just wanted to know how you were doing with that project F150.

Best Regards.