Will not start in the Morning

ALAN CHAPMAN

MEMBER
1992 FORD F-250
7.5L
V8
4WD
AUTOMATIC
156,000 MILES

I have the truck listed above it is the XTL model. I have been having no start issues for a couple months now. It used to start perfect, until the transmission blew the front seal and I ended up getting the transmission rebuilt. Since then it is random if it starts or not. I have done the following.

- Replaced the distributor (tested and no pulse from the PIP).
- Replaced coil.
- Tested for spark (all good when CEL comes on before starting, see below).
- Tested fuel pressure (good).
- Replaced ICM (no change).
- Replaced ICM pigtail.
- Replaced MAP sensor.
- Replaced Ignition switch.
- Replaced ECM Relay.

I am at a loss, if the CEL comes on with the key in the on position it will fire up perfect and run great. In the mornings lately the CEL does not come on and the truck will not start. Try again around noon, CEL comes on and truck fires right up.

Any ideas would be greatly appreciated.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
43,070 POSTS

Yep,

This sounds like a classic engine coolant temperature sensor problem. To be sure you can test the resistance of the sensor to a new unit.

Here is a guide on how to use a voltmeter

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Here is a guide to give you an idea of what you are in for when changing the sensor

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement

Please let us know what happens.

Cheers, Ken

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