Hey all! My 88' XJ was having trouble starting some times so I figured I'd change the spark plugs to help with that issue. Well I changed them this morning, doing one at a time to make sure I don't cross any wires. I went back and made sure all the wires went snug on the plugs and decided to try to start her up. When I started her its like she's missing like I would have a bad fuel filter or something. I'm trying to trouble shoot the issue. Tonight I'm gonna start her and see if the plug wires are arking anywhere but I'm at a loss! I'm also gonna try to put in the old plugs to see if that does anything but if anyone has any advices on trying to trouble shoot the problem please don't hesitate to help! I would greatly appreciate it!


Sincerely, zach

 

Would this have anything to do with it as well?

 

Need to be sure that the wires are connected properly to the correct spot on the distributor cap. I know you said you did this, but mistakes are common here.

You either have the wires in the wrong spot or during the process of changing the plugs, one or more of the plug wires failed. Get new plug wires on there if the current ones have more than 60k on them. And buy GOOD wires, not the cheap set.

Just saw the pic you posted after I posted the above. New wires. Now.

 

when it doesn't start u should pull one of you plug wires off and put one of the old plugs in it and put it to a good ground and see if it sparks when u crank it because i have an 88 and a friend of mine has a 87 and sometimes they didnt start and we found there is no spark and to make a long story short there is a big connector on the driver side firewall and the connection in it goes bad so try to squeeze it together or just do what we did and just cut the connector out and hard wire it

 

^^^THIS!!^^^

 

Does anybody have a diagram showing the firing order for the online 6? And thank you guys so much for the help I'm working on her as we speak!

 

But what I don't understand is that she was running fine before I changed the plugs, other than her not starting every now and then. So could the plug wires have shorted out or something?

 

I believe the firing order is casted into the intake manifold.

 

Autozone.com has free repair guides(they don't have a lot but they to have the firing order) also your misfire could very well be thos bad looking wires. it might have run ok with them but in the proses of changing them all the movement could have crushed the inside of a rusty and corroded wire.

 

Always replace the plug wires when doing a tune up. Today's crappy gas is very hard on the whole ignition system, it takes twice as many kv now than it did twenty years ago to ignite the the fuel. It can take up to 18kv at idle to ignite the gas, the stock coil is only rated at roughly 30kv output.

 

Looks like time for new wires. #1 is at 5:00 facing it from the side, firing order is 153624, clockwise. If you want to find which is missing you can pull wires one at a time from the cap while it's running. Of course it won't change if you pull one that's not working. I usually end up getting zapped. It takes all of 90 seconds to check the hart beat, (CPS)...writeup's C/O Cruiser. Good luck!.. Oh and>> https://www.cherokeeforum.com/f51/he...ix-links-1397/

Renix Jeep C101 Connector Refreshing
　
The C101 connector on 1987 and 1988 Renix Jeeps was a source of electrical resistance when the vehicles were new. So much so that the factory eliminated this connector in the 1989 and 1990 models. The factory recommended cleaning this connector to insure the proper voltage and ground signals between the ECU and the fuel injection sensors. We can only imagine how this connector has become a larger source of voltage loss and increased resistance over a period of almost 25 years. The C101 connector needs to be cleaned at least once in the lifetime of your vehicle. Chances are it’s never been done before.

Almost every critical signal between the engine sensors, injectors, and the ECU travel the path through the C101.
The C101 is located on the driver’s side firewall above and behind the brake booster. It is held together with a single bolt in it’s center. To get the connectors apart, simply remove the bolt and pull the halves apart. You will find the connector is packed with a black tar like substance which has hardened over time.
Take a pocket screwdriver or the like and scrape out all the tar crap you can. Follow up by spraying out both connector halves with brake cleaner and then swabbing out the remainder of the tar. Repeat this procedure until the tar is totally removed. This may require 3 or more repetitions. Wipe out the connectors after spraying with a soft cloth.
If you have a small pick or dental tool tweak the female connectors on the one side so they grab the pins on the opposite side a bit tighter. Apply a true dielectric grease, not the stuff that came with your brake pads, to the connection and bolt it back together.
　　
Revised 11-29-2011


Renix CPS Testing and Adjusting
　　
Renix CPSs have to put out a strong enough signal to the ECU so that it will provide spark.
Most tests for the CPS suggest checking it for an ohms value. This is unreliable and can cause some wasted time and aggravation in your diagnosis of a no-start issue as the CPS will test good when in fact it is bad.
The problem with the ohms test is you can have the correct amount of resistance through the CPS but it isn’t generating enough voltage to trigger the ECU to provide spark.
Unplug the harness connector from the CPS. Using your voltmeter set on AC volts and probing both wires in the connector going to the CPS, crank the engine over. It won’t start with the CPS disconnected.
You should get a reading of .5 AC volts.
If you are down in the .35 AC volts range or lower on your meter reading, you can have intermittent crank/no-start conditions from your Renix Jeep. Some NEW CPSs (from the big box parts stores) have registered only .2 AC volts while reading the proper resistance!! That’s a definite no-start condition. Best to buy your CPS from Napa or the dealer.
Sometimes on a manual transmission equipped Renix Jeep there is an accumulation of debris on the tip of the CPS. It’s worn off clutch material and since the CPS is a magnet, the metal sticks to the tip of the CPS causing a reduced voltage signal. You MAY get by with cleaning the tip of the CPS off.
A little trick for increasing the output of your CPS is to drill out it’s mounting holes with the first drill bit that just won’t fit through the original holes. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.
　
Revised 11-29-2011

 

The center conductor in those plug wires is carbon-impregnated nylon. Not unusual for it to break when you pull the wire off the plug, esp. when they get old and brittle and it's stuck on there good.

Also..did you check the plug gap before installing? I've gotten "pre gapped" plugs that were gapped shut from being dropped.

 

Oh my gosh thank you guys do much for the help. I'm getting good plug wires today then running through each plug checking the gaps the I'm gonna clean the $hit out of the C101 and see where that puts me. But again guys thank you so much for the help!!! Your life savers!

 

Great! Please come back and let us know. No doubt cruiser has helped out allot of folx with tips like on that C-101.

 

Alright guys I cleaned the C101 then pulled each plug one by one and found that the fourth one had been smashed shut X( she's purring now