ItsNobody

My problem started 2 months ago....A friend gave me an XJ 1988 Jeep Cherokee 4.0 4x4 5 speed which ran okay when i got it but it had a full tank of about 3 month old gas. So i ran Seafoam in the tank to try to give the gas some life. Everything was good until i wanted to test the 4x4 (heh sounds silly huh?) and climbed a hill. She stalled at the top of the hill and wouldnt start without starting fluid from there on out. The fuel pump had been replaced before i got it so i replaced the fuel filter and AIC (which has a different name in the chilton manual) and still had the same problem. By the way i tried cleaning my AIC with throttle body cleaner which in the proces i mustve pulled on the actuator in the AIC which made the vehicle bust off everytime i turned the key but also made the damn thing rev sky high. Well i started digging around and i see where some idiots spliced ( a very crappy splice at that) the CPS wire. So i redid the splice and now she will bust off and fire up! But now she idles crappy and if i rev it she stalls after the rpms drop. If i barely tap the gas she wont die but if i gun it she stalls when the rpms drop to idle speed. Any ideas? Im not a mechanic , only a guy wanting to hit some mud this summer so please dont get too technical on me!

ItsNobody

Anyone have any things i can check? I'm over here lol

cruiser54

Sounds like ossibly a fuel delivery issue since you mention starting fluid.

On the driver's side inner fender is a fuel pump ballast resistor. Make sure the connectors are tight. It's okay to bypass it if you want.

cruiser54

That said, I'm gonna suggest you take some time and review the "pink link" in my signature below. Do # 1,2,and 3 before getting off on any rabbit trails and spending money on sensors etc.

ItsNobody

Yea i cleaned up the ballast connections yesterday when i spliced the cps, Im thinking of cleaning the c101 connection like in your link. Thanks for the reply cruiser

cruiser54

Do the ground refreshing also. That's why it's #1.

Do the connectors also, #3.

Here's how your CPS wires are supposed to be routed.

cruiser54

You can also test your CPS output quite easily:

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 the upper mounting hole to 3/8" from the stock 5/16", or slot it so the CPS bracket rests on the bell housing when pushed down. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts.



　

　

Revised 01-26-2013

ItsNobody

Thanks to you cruiser while i checking the ground on the block by the dipstick I noticed a spark plug wire was faulty....when I went to remove the plug to make more room to tighten the bolt back in it came loose to easily and left the clip on the spark plug. Going to get a new set of plug wires friday and ill report back my findings.

cruiser54

I'm now responsible for another dumb luck fix? Works for me!!!!

ItsNobody

Well...Maybe not lol When i found the faulty spark plug wire I had just cleaned the C101 connector. I replaced the wires to no avail. And now after cleaning the c101 she wont crank. Well...she did after the first cleaning (that tar crap is a bish to clean out!) but she ran a bit rougher and choked down a few times on me on the way home. But after I replaced the wires I took a look at the timing order diagram for the distributor from my chilton book. Seems like someone messed up the order (I think). Would u check out these 2 pictures and tell me if the order is right or wrong? I cant tell which way the chilton diagram is telling me to look at the motor.

ItsNobody

#6 is directly across from 1 ...btw look how tight the #1 spark plug wire is...and theres not enough slack in any of the other wires to swap it out I am kinda thinking it is CPS now... Hell I dont know really im no mechanic. I have a feeling after working all the kinks out of this jeep I will become one lol Im getting fuel. This damn thing ...I replaced the spark plugs (which were fouled out very badly) with the Bosch +4 Platinum Plugs..I wanna see how she runs badly! lol So i think my problem changed to a no spark issue

cruiser54

Click on my "pink link" and see post # 13.

ItsNobody

Why would the distributor timing be off if it ran before? I will try it once I can get a new cap. By the way I am not questioning you. I just went outside and cleaned the c101 again...I also forgot last time i cleaned it to push the connectors tighter with a pick, And also would it be ok to put Dielectric Grease on the connectors of the c101?

Pelican

Dielectric grease is an insulator. It will in no way help with improving electrical contact on the C101 connector. I would wait until I got everything sorted out and running and then use the grease to keep moisture out off the various connectors.

No. 1 plug is at the front (next to radiator) of the motor and is marked on the distributor cap. Not sure what you are asking but just follow the wires on around from there. The picture looks to be the same as mine.

I have used standard Bosch platinum plugs for many years in my 4.0. Many say that the 4.0 will not run well on these but they are simply wrong when making a flat statement that applies to all XJs. On the other hand I have never heard anyone suggest that the oddball plugs such as the +4s will perform well. I will leave that question to others for comment because I have no personal experience with them.

I assume not your problem but did you check continuity of the ballast resistor as well as clean the connectors?

ItsNobody

Yes I checked the ballast. And exactly where is it marked? I do not see it. I know the timing order of the motor i just need to verify my distributor spark wire configuration is right.