bugman7

My daughters 95 Cherokee got a leak in her radiator and so we decided to go ahead and upgrade it two a 2 row all aluminum radiator. During the radiator replacement I also back washed the heater core and looked at the water pump to ensure it was still good since I had the radiator out. I also went to change the thermostat out and noticed there wasn't one in there so I put a 195 degree one in it.


After all this was done I decided to go ahead and do a tune up and replace the spark plugs, wires, cap, and rotor. I used NGK V-Power Spark Plug FR51 as the replacement plugs and a SMP Distributor Cap FD177, and the SMP Distributor Rotor FD316, along with the SMP Ignition Spark Plug Wire Set 7648. After all was completed I used the Haynes manual to put the plug wires back onto the distributor and tried to start it. It would not start at all so I decided to look at my 97 Cherokee to see how it was connected to the distributor and noticed they were all off by one.


I corrected this issue and it started up but has a real ruff idle and it is bad enough that I didn't want to drive it. I checked to ensure there was spark at each plug. What should I look for next? Would using the NGK plugs on the 95 cause this to happen?


Thank you for all your help.

Turbo X_J

Courtesy of DFlintstone:
"The book's wrong! #1 is at 5:00, viewed from the side. 153624 clockwise."

Firestorm500

I used NGK Iridium plugs on my '92 and '88. I recommend those.

If your NGKs have an electrode like a standard plug, they should be gapped at .035. If they have the needle type, it should be .060. Be careful not to damage the needle type.

#1 on your distributor should be at the 5 o'clock position. Quadruple-check your wire arrangement and firing order. Take your time and have someone else check your work.

Look around to make sure you haven't knocked a sensor wire or especially a vacuum hose/fitting loose while you were doing all that work under there. A small vacuum leak can cause really bad running problems.

BLKXJ 96

Most of the weird issues I have seen with a 4.0 and drive issues is plugs....if you're not running the Champion RC12YC gaped at .035 there always seems to be a problem........This motor runs best with these plugs.....The End!!!!

Iridium plugs are always more trouble than they are worth.

fb97xj1

Have you checked for any codes? Try the key trick. Turn the key to RUN then OFF, RUN then OFF, and once more to RUN (leave it on RUN), within 5 seconds. The Check engine light should come on, then go out, then start flashing if there is an issue. There may be nothing, but its worth a shot.


http://www.go.jeep-xj.info/HowtoECUcodes.htm

BlueRidgeMark

No.

One plug might be some better than another, or even noticeably better, but any plug that is the same size and same heat range is at least going to run decently.

You've probably got the wires swapped. Haynes is garbage.

bugman7

I figured it out. When comparing my jeep to hers for firing order I stopped after finding the one wrong. There were two others that were swapped. Got those swapped and it is running great now. Thank you for the help. You'd think that Haynes would have fix that major mistake by now.

Firestorm500

I disagree. Absolutely no issues with NGK Iridiums for over 90,000 miles on my '87 and about 35,000 on my '92. Same sets. Never a misfire.

No rumor. Fact.

I hate Champions. Too many defective ones in my experience.

No rumor. Fact.

cruiser54

Agree 110%.

For 47 years, that has been my exact experience. Bosch sucks also.

cruiser54

And for future reference: