Starts, them dies

My '89 XJ 4.0 (Renix) with ONLY 301,000 had an issue on the trail last weekend. It was idling for a little while (less than 5 min) and when I returned to the vehicle, it had stopped. I turned the key to start it and it started right up...for about 2 seconds...then died. It did that four times in a row, then on the fifth time I had a friend crank it while I wiggled the wires to the ballast resistor...making sure they had good contact. That time it started and continued to run. On the way home from the trail, it almost died one additional time as I was getting on the highway, but caught and kept running all the way home (about 15 miles).

So, any ideas of what I should test/replace before I head to the trail and get stranded? The CPS is a fairly new (about 1-year) dealer part. Oxygen sensor is also fairly new (replaced trying to get better mileage). Probably in need of routine tune-up parts (plugs, cap, rotor).

Thanks in advance.

Well, if wiggling the wires on the ballast resistor allowed it to start and run, which you claim it did, gotta start there.

Bypass the resistor with a short piece of wire between the terminals of the resistor. That will tell you if that is root cause or if it is something else.

You can safely bypass this resistor; it's purpose is basically to reduce noise of the fuel pump. Many leave the resistors bypassed.

Is there a way to test the resistor? Or just bypass then run and see if it gives more problems? Like to know before heading into the backcountry.

Well, if you bypass it and it runs properly, then the ballast resistor is bad. And from my understanding most of the aftermarket ones are crap. I have bypassed mine and have no issues.

get rid of the resistor. it's a useless failure point waiting for a bad time to happen.
cut the terminals off the wires, strip, solder and heatshrink wrap them. then never worry about that again.
when you're cranking, the power to the fuel pump bypasses those wires. that's why you were getting a momentary start, then dead when you let the key return to the run position.
I've deleted that thing on two xj's and an mj with no ill effects.

Agreed. Bypass the resistor. It's only there to quiet down the fuel pump.

But, if that doesn't solve it, I would do a fuel pressure test. Your fuel pump could be dying or the hose inside the tank is deteriorated.

Also, as some preventative measures, I would click on the link below and do Tips 1,3,4, and 5.

http://www.naxja.org/forum/showthread.php?t=1115935

Thanks for your replies...and especially for Cruiser54's tips! I'll bypass the resistor and take care of the other tips...then keep my fingers crossed!

And you better keep in touch!! LOL.

bypassed mine for the same reason months ago.

the stock resistor is 1.1ohm. the local parts store only had a 1.25ohm, and it caused fuel starvation. If you want to keep the resistor make sure you get one with the same impedance or you might get the same results I did. good luck...

Thanks again. I'll be bypassing the resistor. In the mean time, I hope it's the cure as it will be in the garage for a week or so...installing new RCV front axle shafts and changing out a leaking front passenger side axle seal. Should cure the busted front axle u-joint I experienced last weekend! I'll try to document for a future post...so you can see how it goes.