94 will not start when temp is below 30degrees F.

[CHuntMD]

It's been really mild in the Washington DC area. This problem happen every time the temp is below 30-32 degrees. The engine will crank and crank but will not start.

I hear the fuel pump primeing and I've already replaced the FP & EEC relays.

This is the 4.0 OHV with 146,000 miles.

What else can I check?
Chris

 

[savagefan]

Do you get spark when it doesn't start? IAT and ECT are your temp sensors lots of info on this site about them. But check spark first.

 

[CHuntMD]

Is IAT same as IAC?
Waht and where is the ECT?
CH

 

[savagefan]

No, IAT is intake air temp., located on upper intake behind IAC. ECT engine coolant temp sensor is on lower intake below throttle body area. Do you have spark at cranking?

 

[CHuntMD]

Were back in the 50's again and it starts just perfectly.

Maybe Mon or Tuesday it will be below 30.
http://www.weather.com/outlook/events/sports/tenday/20772?dp=ltempdp

If these sensors are too $ I'm going to replace them today.
CH

 

[savagefan]

Pull codes if either of these is out of range you'll get a code or maybe there's something else that will show up, keep us posted and good luck.

 

[CHuntMD]

Replaced the IAC about $60
Replaced the IAT about $15 both at Auto Zone.
ECT gave me some problems. Two parts stores had the "wrong" part. The connector was different. Had the part guy lookup a 1993 OHV 4.0 and that was the right part. Lesson learned: Take the old part with you, if you have another rig to get you there carquest was more $ at $26 but they had the part.

You need to take the intake hose off to get to the ECT and it is a little tight for the ol' wrench. Also cleaned the intake by the butterfly valve with BG intake cleaner.

Don't know why they have the warning sticker not to clean the intake???
Replaced belt as the intake hoses was out of the way.

So, last two mornings have been right on the tempature border. 31-33degrees F but it has started right up.

 

[JDraper]

Maybe the truck is telling you it wants to move south......

 

[CHuntMD]

Maybe when I retire but to many job opportunites in Wash DC area.

It's been 5 whole days with mornings under 32degrees F and the old 4.0 is starting every time.

Funny how even my local FORD dealer and even Pat Goss's Garage could not figure it out (was not cold enough was their excuse)
CH

 

[CHuntMD]

Replaced another part

2 weeks and it started until this am. 21degrees and same problem.
Sprayed some BG throttle body cleaner into the intake to see if it was fuel related. Still no start.

Found a CPS (crankshaft position sensor) at Advanced auto parts for $38 and spent 2 hours taking the old one off and the new one on in 25degree and windy weather.

Started on first crank. It sjhould be under 20 degrees on Monday morning so I'll see what happens.
CH

 

[ma96782]

I'd check the battery condition......CCA......means something when cold weather hits.

Aloha, Mark

 

[BrooklynBay]

Maybe it's your ignition module. If it's not sending a signal to your coil pack to fire the spark plugs, then that might be your problem. Check this thread: http://www.explorerforum.com/forums/showthread.php?t=153111