02 Focus DOHC Hot Start

[223splatfactor]

First, been lurking for a while. Lots of good info here.
I've spent hours with the search function, no luck.
Wife drives the car 35 miles to work. Car runs fine, gas mileage in the high 20's. IF car is stopped(engine turned off) it won't restart until everything is cooled down. It does not turn over. Can hear the fuel pump run-nothing else. No codes. No check engine light.
Seems like it must be a sensor that can block the ecm .
Any help would be appreciated!!!! Thanks-Neil

[Sponsor]

[my_beautious_ZX3]

what happens if you turn the key with your foot lightly on the gas?

[223splatfactor]

Nothing......Neil

[223splatfactor]

Thanks for the one reply...... This can't be an isolated problem.
Has anyone had issues with the ecu/ecm similar to theis problem??????

HELP !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[whynotthinkwhynot]

No turn over could be due to several things.

1) PATS: is the yellow lock flashing on the dash when it doesn't crank?
2) Ignition switch
3) Neutral Safety switch: try shifting out of park into N and see if it will crank.
4) Starter relay: this one you'll have to simply buy, I don't think it will swap out with another relay- nothing else is the same size.

A relay might seem to be a simple shot, but I have only ever known a handful of bad relays in 25 years of fiddling with cars. It can happen, but really, check other things. I'd be more certain that the ignition switch was the problem, but I can't explain why it would need to cool off. Likewise with the N/S switch which is in the shifter and prevents you from starting the car in anything except P or N. I don't think this can be replaced without replacing the shifter.

A loose starter terminal or battery terminal can cause a no-crank issue when the battery is warm, but I'd expect some clicking.

[223splatfactor]

Thanks for the reply.
No yellow light.
Tried putting into neutral....
Batt and starter terms are tight.....
The ignition switch...why when warm/hot????
Relay...maybe....only 112,000 on the odo.
I appreciate the reply. This is making me crazy....Neil

[BC_ZX3]

It's not an PCM / ECU issue.

For a no start, no crank condition, check the following:
PATS (Passive Anti Theft System) is behaving normally.
The battery is in a good state of charge and battery terminals/cables are tight and corrosion free.
The starter motor relay is good. Swap it out.
The clutch pedal position sensor or neutral safety switch is functioning properly. Bridge it with a jumper.
The ignition switch is good. Test with a multimeter.
The starter motor itself tests OK. Inspect for loose connections/cables first.
The wiring associated with the starter circuit is intact. Multimeter and circuit diagrams again.

For an intermittent condition like yours, you have to be methodical and check each component.
If I were to suggest a quick check, I'd say check the clutch position sensor (if it's a MTX) first as the pedal neutral switch does get stuck.
Other than that, the next time it fails to start, you need to check the starter circuit as to where the voltage is being interrupted.

edit: whynot beat me to it.

[BC_ZX3]

Wires can become more flexible, electrical connections that are "border line" expand when subjected to heat, intermittent connections result. Cools down, things contract, back in business... temporarily.

[223splatfactor]

UPDATE !!!!! The starter relay showed 3 terminals that were discolored-probably hot.
Replaced with new one from parts store..........Still have the same problem.
Thanks to all who have responded. I really appreciate it. I guess next is to pull the starter. I AM Not looking forward to that!
Thanks-Neil

[whynotthinkwhynot]

BTW... did you check your grounding? We had another FF with a similar problem that was due to grounding. There should be one big wire off the negative battery terminal that goes to the engine block. There should be a copper shoelace that goes from the engine to the chassis, and 2 small ground wires that go from the negative battery terminal to the chassis and the wiring harness.