Intermittent Starting Problem

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Jul 20, 2008 | 11:52 AM

mchild

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Intermittent Starting Problem

I have a `95 Explorer w/ 4.0L push rod V6 and auto trans. Truck has about 195K miles.

Over the last several months it has had an intermittent starting problem. Turn the key and the motor cranks over, but does not fire. Most of the time, but not always, if the key is turned off then back on it will start without issue (not just release the key from the start position and then another attempt at starting). A few times it has taken a couple of attempts before it will fire.

Bad sensor somewhere? Bad relay? Any ideas as to what I should start checking?

Jul 21, 2008 | 01:32 AM

aquanaut20

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From: BC Canada

Check for a tired CPS or FP relay. Cheap enough to replace them all.

Jul 21, 2008 | 07:58 AM

marragtop

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From: Baltimore

When you turn the key to the ON positon, you should hear the fuel pump run for a second or 2. If you don't then it's a fuel delivery problem like the fuel pump relay.

Jul 21, 2008 | 09:10 AM

mchild

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Quote:

Originally Posted by aquanaut20

Check for a tired CPS or FP relay. Cheap enough to replace them all.

CPS= Crankshaft Position Sensor?

When you state that they are cheap enough are you referring to relays of CPS?

Thanks

Jul 21, 2008 | 09:14 AM

mchild

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Quote:

Originally Posted by marragtop

When you turn the key to the ON positon, you should hear the fuel pump run for a second or 2. If you don't then it's a fuel delivery problem like the fuel pump relay.

My fuel pump is fairly quiet so you can't hear it unless I'm out of the vehicle and standing back near the rear door. I'll have to figure out a way to monitor that - or as aquanaut20 is suggesting, just replace the relay.

Jul 21, 2008 | 09:23 AM

marragtop

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From: Baltimore

The FP relay is in the power distribution box under the hood. They are only about $7 and it's an easy fix. You could also try switching it with one of the other relays. I think the AC relay may be the same.