97 5.0 awd no start issues in the mornings

[93 x]

Hello my name is Gordon and I work in a shop in Seattle. recently we had a customer come in for a no start issue on his 97 5.0 awd. so what happens is ONLY on cold mornings it will not start and has no spark, but has injector pulse. we put a crank sensor in it because before it had no spark or injector pulse. the previous shop which is a dealership put a fuel pump and a computer into it. I had another 5.0 explorer in here so I swapped computers and it did the same thing. im pretty much at a loss here because it has injector pulse but no spark :scratch: im thinking I might put in a cam sensor and se what happens. I have no codes what so ever. any input would be great!

 

[93 x]

well im still trying to figure it out but I guess its time to go home. ill keep you guys posted.

 

[Turdle]

I'd check the crank sensor wiring over real well.

Try re seating the Square harness plug right over the intake manifold also.

I assume if a heater was blown into the engine bay the truck starts well? If so, maybe directing heat at certain areas would help troubleshoot this.

 

[93 x]

turdle its great to hear from you. the only issue with everything is that seattle is a pretty mild temp. so in the mornings its nice and chilly but once it hits 8-9 o'clock the truck starts every time. so I have to come in early just to diagnose it.i guess I could get some sorta heat in some places. thanks for the help I never thought to reset the main harness.

 

[93 x]

man this truck is driving me crazy! It was not starting then I had to get a phone call I came back and bam started right up. I wish I could be somewhere really cold and I could blow heat in places. I may just go pick up some air in a can and turn it upside down to blow cold air onto things. resetting the main harness did not help any and all those pins are good and clean.

 

[Turdle]

Just a hunch--

Next cold morning, before anything else-cycle key on and off 4 times. Chek the Crank sensor voltage with just the key on.

on the 5th time turn the key all the way to start. ( wondering if it isn;t actually fuel leak down)

Does the oil pressure needle move while cranking?
Coolant level up?

The only sensors I can think of that would behave differently while cold are the MAF, ECT and IAT sensors.

OH!!!
The PCM relay--could be an intermittent connection in the socket. Try swapping the PCM relay with another one.