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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 47985
Experience:  16 years experience
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My 98 ford f150 4.2L will not start without a delay. The

Customer Question

My 98 ford f150 4.2L will not start without a delay. The delay when it is 80 degrees F and hotter is about 6 seconds and increases as temps. drop. When it's 30 degrees or less, the delay takes up to 20 mins. During the delay (crank won't start) period, I can hear a very faint humming coming from under the truck. When the truck is ready to start, the CE light does a real quick off/on blink and the humming stops. The truck starts and runs perfect whether idling or when I put my foot into it. I can't locate the fuel rail or the pressure relief valve to see if I have fuel pressure during this delay or not due to all of the other engine parts that may be hiding it from view. After reading a hundred or so forums, I still haven't found anyone that has had this delay. Or they don't know about the delay and just describe it as "crank won't start." I checked the FP relay and fuse and they are both good. The truck only has 30K miles on it so it has done a lot of sitting during it's days. I have read fixes to the "crank won't start" problem from a loose wire/ bad wiring harness in the system to bad PCM with a lot of people changing the fuel pump and it not being the solution. It looks like the PCM on my truck will run about $400-$500, which I can't locate on my truck, and replacing the fuel pump via bed removal though cheaper than the PCM, will take a whole day of labor with my skill level. Have you ever heard of this and can you make any suggestions of things to check before I replace the PCM or FP?
JA: Has your car been stalling?
Customer: No
JA: Are you fixing your F150 yourself? What have you tried so far?
Customer: Checked the FP relay and fuse. Both are good.
JA: Anything else you want the mechanic to know before I connect you?
Customer: Not than I can think of.
Submitted: 7 months ago.
Category: Ford
Expert:  Chris (aka- Moose) replied 7 months ago.

Welcome, I'm Chris (aka Moose), my normal schedule online is around lunch and after dinner till early morning.

I too agree checking the fuel pressure is a good place to start. You want to see an immediate spike of 35psi or more when the key is turned on. Below is a diagram of the test port.

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Thanks for using Just Answer, Chris

Customer: replied 7 months ago.
Thanks for that suggestion Chris. I didn't get a chance to do anymore checking on it, before it was scheduled to have the recalled fuel tank straps replaced. So I just had them diagnose it. After their diagnostics tests to eliminate any thing else, or additional problems, they concluded that it was the EOM. The humming I heard coming from underneath my truck until it was ready to start, was the fuel pump in prime mode. The tech said that it was failing to shut off after 2 secs., and that decision... was coming from the EOM. Replaced, installed, and re-programmed for $530. The parts for my fuel tank and the EOM will be in in 3-5 days. I'll let you know what the results are.
Expert:  Chris (aka- Moose) replied 7 months ago.

Thanks for keeping me updated.

Customer: replied 7 months ago.
The Ford dealer's diagnosis was correct. With the truck being a 98 model, Ford didn't have a new EOM for it so they had to use a rebuilt one from a third party. While they were attempting to diagnose it, they found my battery was only producing about 50% of it's cranking power. Needing 100% (or close to it) to have a reliable diagnosis I told them to replace it. With that being said, the new battery, EOM replacement (1-year warranty) and taxes came to $680 for the total bill. Ending my 2-year dilemma of waiting from 6 seconds on a hot day, to 20 minutes with temps. under 30 degrees made it well worth that. I hope the information I have shared will help you point someone in the future, directly to the problem instead of having to replace several parts as a process of elimination and they reward you handsomely for it. Thanks again.
Expert:  Chris (aka- Moose) replied 7 months ago.

Glad you got it resolved, sorry I was not given a chance to help you diagnose this.

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