Won't Start Cold, Common Problem?

[chopper35nj]

It got realy cold lastnight (5 deg.) and for the first ever my Comanche would not start. The engine turns over freely and has been running great, it tryed to start twice, so obviously I have all of the elements needed to run (suck, squeeze, bang, bolw) are there and I can hear the fuel pump run until the system is pressurized..... So, I guess the question is, Is the 4.0 known for starting hard in the cold and is there a cure for this problem?

 

Thanks for any help.

Eric

[ftpiercecracker1]

Yes, but not not starting. Normally it just takes a few more cranks when its cold, not a complete failure to fire. Is it even trying? or does it act like its totally dead?

[chopper35nj]

No, it turns over fine and does fire, it started twice on seperate occations and died right away then just turns over.....and over.....and over.....and over, you get the point. My old Grand Wagoneer with a 360 would start in any temp north of 50 below and my Eagle with a 258 never let me down. I lived here in the great white north for 25 years but this is the first time that I have had my Comanche here in the winter and have never experienced a 4.0 in the cold. I guess I'll start with a bottle of Drygas and a can of starting fluid.

[mountainman]

Possible fuel pump resistor issues. you bypass it yet?

[chopper35nj]

No, I have not done that. I will try that in the morning. Some say they bypass them on every or Comanche or Cherokee that they get just to take out the week link. Am I understanding this correctly, the resistor was only put there to cut the voltage to the pump in order to quiet it and that removing it will improve the performance of the pump?

[Eagle]

Check spark plug gap.

[ftpiercecracker1]

Possible fuel pump resistor issues. you bypass it yet?

 

He said he can hear the pump prime when he turns the key, that would mean the resistor is fine.

[banshee]

a question of my own do or have you ran gasline antifreeze in your truck?

why thinking ice in fuel filter either choking off or restricking flow

 

just an idea... B...

[chopper35nj]

Plugs are fresh (less than 500 miles) and yes I did gap them. I never trust a plug that is "factory gapped". Yes, I can hear the pump prime when I turn the key on. No, I have never run gas line antifreeze in this truck, I haven't been driving it that long. After many years in Vermont it is kind of the go to first move when you have this happen.

[cruiser54]

Pump may be prining but at a low pressure.