Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: Thomas.hummelt on January 25, 2015, 04:15:04 PM

Title: Weird Cold Starting, WTF
Post by: Thomas.hummelt on January 25, 2015, 04:15:04 PM
I own a Jeep Grand Cherokee, 1994 4L Inline 6. It has serious issues starting when its -10 or lower, even when its plugged in. However, anything above -1 it has no problems. The engine cranks and cranks until i put pressure on the gas, and the only way i can get it to start when its cold is to pump the gas, and seeing as its fuel injected, im confused on why i need to pump the gas. I changed the air temperature sensor in the engine and that didnt really help. Any ideas?

-I can hear the fuel pump running when i start
-Starts without fail 100% of the time when its warm out
-Even when plugged in it still has difficulties anything colder then -10
- Next to new spark Plugs, distributor cap
- New fuel filter
- Brand New tranny
- Everything else works fine.
Title: Re: Weird Cold Starting, WTF
Post by: morerpmfred on January 25, 2015, 05:30:11 PM
Fuel filter. Super fine sludge in there and a tank of gas with water from some time ago. When warm , fuel flows through but when cold, frozen sludge does not let fuel through. Used to be kinda common but with good fuel filters at the pumps and alcohol in the fuel it went away.
Title: Re: Weird Cold Starting, WTF
Post by: apeman on January 26, 2015, 02:09:52 AM
Cps. The Boone of the 4.0l.
Title: Re: Weird Cold Starting, WTF
Post by: Immortal on January 26, 2015, 06:09:37 PM
Cps. The Boone of the 4.0l.

 Bwahahahahahahahahaha!!!!!!!!
Title: Re: Weird Cold Starting, WTF
Post by: Thomas.hummelt on February 01, 2015, 11:36:47 AM
Well i just put a new fuel filter in, and i checked the fuel rail, and there is gas getting to the pistons, there is just no ignition, i checked the sparkplugs there almost new, the Dcap is brand new... i just cant FIGURE THIS OUT AND ITS KILLING ME
Title: Re: Weird Cold Starting, WTF
Post by: Immortal on February 01, 2015, 03:28:52 PM
Crank position sensor.
Title: Re: Weird Cold Starting, WTF
Post by: cLAY on February 01, 2015, 05:07:03 PM
X 5 for CPS.
Title: Re: Weird Cold Starting, WTF
Post by: Thomas.hummelt on February 02, 2015, 12:00:21 PM
Yeap ive been doing some research and that sounds like a problem, damn those things arent cheap either, but as is the life of a jeep owner. However would the CPS affect the idle? it seems that i can get it to start but it will die after a second of running even if its "warm" If its been "hot" for a while it has no problem starting back up and it wont die but if its been sitting for about 6 hours it will sometimes start up but die.
Title: Re: Weird Cold Starting, WTF
Post by: Immortal on February 02, 2015, 07:44:49 PM
The cps tells the system when to spark. It's a sensor, they do weird things at different temps.