Won't start in the cold.

I have a 1989 XJ with the 4.0, Auto transmission. I have spent a lot of time searching threads and haven't quite found anything similar to my problem. I live in a cold climate and in the winter time, my jeep doesn't want to start. The starter is turning the motor but the motor doesn't even think about starting. I have checked and it's not getting spark or fuel. The fuel pump is new and I can hear it kicking over when I turn on the ignition. It sounds strong. New fuel filter also. I have tried spraying starting fluid in the intake and that doesn't help (Probably because I'm not getting spark).

It starts and runs fine in the summer months. In the winter, if I pop the hood and let the sun shine on the motor for an hour or 2 it will fire up and run great. I got it to start up today and we wheeled all day with no problems. Toward the second half of the day we did have a few minor issues. After we would take a break and try to fire it back up, it would run rough. It did this until I got a bit down the trail and it would run fine.

Not sure what the issue is but I suspect I have a sensor somewhere that may be getting old or going out. It has done this for the past two winters. I have been so busy I haven't worried about it because I didn't have time to go out anyways. My new schedule is allowing me more time to wheel so I want a reliable rig.

I figured I would post up my problem before I started throwing parts at it. Would a bad battery/battery cable cause the rough running/non cold starting? From sitting so much, the battery has a tough time getting it going.

Thanks in advance,
-Gerrit

Check your IAC. Just clean it to rule that out. It doesnt explain why you dont have fuel or spark but saying that once you warm it up it works makes me think IAC.

First thing that comes to mind is metal contraction.

Cold = metal shrinks and connections that are marginal will become "opens".

Start with battery, cables, and grounds.

CRITICAL on the Renix system are grounds. The grounds at the dipstick tube--yep, that is where the dipstick engineers put them--are CRITICAL to engine management. Did you know that the ICM (ignition control module) and the ECU (engine control module) BOTH ground at the dipstick tube?

Ok, start with the battery. Fully charge it--overnight (Ok) or for 24 hours (Best). While it is charging completely remove both battery cables from the vehicle. Clean both ends of the cables. Now, use an ohm meter to test the resistance of each cable--should be near ZERO; if not replace the cable(s), and use 4 or 2 ga. Also, the ONLY ground for the entire unibody is the POS braided strap from the head to the firewall. Replace the strap with a 4 ga cable. Make sure that the contact surfaces are down to bare metal, treat the surfaces with an anti-corrosion product (any hardware/paint store) and make the connections TIGHT--do the same for the dipstick grounds!

Ok, take your battery in and have it load tested--did you know that the Renix engine has to "spin up" to 300 RPMs before the CPS/CKP crank sensor can generate enough of a signal for the ECU to fire the coil? Yep!

Ok, when your homework is done post back and you will be graded.

joe_peters said:

Ok, when your homework is done post back and you will be graded.

Click to expand...

Graded straight percentage or on a curve??

If you have verified "no-spark" when it won't start, that is obviously what you have to concentrate on.

Basics first as Joe mentioned. Battery, cables, grounds. Freshen your cable connections and grounds and LOAD TEST the battery which is the only conclusive way of determining battery condition.

Certainly there are other possibilities but by adopting a methodical simple-to-more complex strategy, you'll figure it out. Test your way to a solution.

Good luck and let us know what you find.

Thanks, everyone! I'll get going on that today and see what I find.

I know that the normal failure for CranK Position sensor is to never work or fail when hot. However, it is also the leading cause for no spark AND no fuel. I would check the connections to the CKP (unplug and replug a few times) and if problem continues check the resistance. Also unplug/plug ASD relay a few times.

Try this... first, watch the tach...if it doesnt move while you are trying to stat the jeep, jiggle the wires around the bulkhead connector under the hood and any connectors close to it. Try to start the Jeep and watch the tach, if it starts bouncing, she'll start. If not repeat the process with a little more strength. I had a bad wire in the bundle and had to go through this process for months before i stopped being lazy and fixed it.

My wife's jeep was having issues so I had to take a break on mine. I finally was able to take out the battery (an optima red top) and take it in to get tested. It tested bad and a new one is on order (thank God for warranties). The battery cable also looked fried so I bought a new one. The new red top is due to come in tomorrow. I'm gonna try a new battery and cable and then see what happens. Thanks again for all of the tips and advice.
-Gerrit

FLAGXJ said:

I finally was able to take out the battery (an optima red top) and take it in to get tested. It tested bad and a new one is on order (thank God for warranties). The battery cable also looked fried so I bought a new one. The new red top is due to come in tomorrow. I'm gonna try a new battery and cable and then see what happens.

Click to expand...

If the battery tested bad, that has to be replaced as you're doing. Gotta have a solid electrical system before moving on.

Let us know what happens with the new battery and cable.

Wouldn't hurt to add a ground wire , at least 4 gauge from the dipstick tube bracket to the stud on the passenger side fender. Refresh your grounds per Joe Peters.

Got the new battery and cables in. It was 20 degrees this morning and fired right up. Seems to have fixed the problem. It would have never started before when it was that cold. I'm going to get my alternator checked to see if that is what is draining the battery. The wiring from the alternator to the battery was in pretty bad shape so that may have caused it too. I don't think it's normal for red tops to go bad in 2 1/2 years.

My motor is a wiring nightmare and I could always use more grounds. I've got an extra 4 gauge wire in the garage. I think I'll use the extra ground.

Thanks again, everyone!

This article should be required reading for all XJ owners: http://www.olypen.com/craigh/charge.htm

I agree. A definite upgrade for me.