No spark. CPS???

[Carnuts]

My XJ has been parked for a year or so out of frustration. Would love to drive it again. If I disconnect the #1 plug wire to check for spark while turning over the engine there is no spark seen. Coluld my CPS be shorted out? Or something else? Here is a link of some of the ongoing problems with it.
http://www.naxja.org/forum/showthread.php?t=51815&page=3

Can someone please help me get my XJ running again.

Thanks

[Matthew Currie]

My XJ has been parked for a year or so out of frustration. Would love to drive it again. If I disconnect the #1 plug wire to check for spark while turning over the engine there is no spark seen. Coluld my CPS be shorted out? Or something else? Here is a link of some of the ongoing problems with it.
http://www.naxja.org/forum/showthread.php?t=51815&page=3

Can someone please help me get my XJ running again.

Thanks

Away from home with no manuals, but as I recall, an ohmmeter across the terminals of the CPS (unplugged) should read something in the vicinity of 125 ohms, with a pretty good tolerance plus or minus (for an 87-90 CPS). An open circuit (infinite resistance or out of range on a digital) is the usual failure here, but you should also check the wiring for shorts, etc., and the connector for bad contact. Sometimes a badly routed wire will short against the hot exhaust manifold. CPS is a good candidate for checking first, though, for no spark.

[Blaine B.]

Could be your pickup coil.

I had no spark, replaced the CPS and piclup coil. It was one of the 2.

[Carnuts]

Put a new CPS on. No dice! Still turning over with no attempt to fire. Any other ideas? I'm getting really frustrated with this. Needed it to drive to work tommorrow. Help!

[Blaine B.]

Pickup coil below the distributor cap?

[Carnuts]

Pickup coil? The only thing I see under the distributor cap is the rotor. Then a big metal sheild.

[Matthew Currie]

Pickup coil? The only thing I see under the distributor cap is the rotor. Then a big metal sheild.

Under that metal shield is the "camshaft position sensor," which, although its job is actually to synchronize the fuel injection rather than the ignition, has the mysterious and annoying property of preventing a spark if it doesn't work.

[Blaine B.]

I origionally thought it was the cam sensor, but when nobody had that available, I finally described what I saw to a local Van Senus shop...he told me it was the pickup coil. Its a plastic disc which slides over and snaps into the base of the distributor. It has a plug which you pluginto the harness leading to the old pickup coil.

All I know is what I bought was called a pickup coil.

[Carnuts]

My haynes manual shows for a 2000 6cyl on the cam paosition sensor. Going out to take a look since my is not a 2000. It is a 1990 if that was not mentioned before. I ill let you know what I find out.

[Carnuts]

I assume it is the black piece that appears to wrap around the inside of the distributor shaft. Do I just take out the small screw to get it out? Or??

[langer1]

I assume it is the black piece that appears to wrap around the inside of the distributor shaft. Do I just take out the small screw to get it out? Or??

Most of the time they come with a rebuilt dist. You have to take the dist out and apart to replace it. My 90 will start with the Dist unplugged.
You should do some voltage checks instead of just throwing money in parts.
PM me with your email and I will send you the manual.

[Carnuts]

Most of the time they come with a rebuilt dist. You have to take the dist out and apart to replace it. My 90 will start with the Dist unplugged.
You should do some voltage checks instead of just throwing money in parts.
PM me with your email and I will send you the manual.

Ugh. Had a feeling that was the case. I sent you a PM.
Thanks!

[Blaine B.]

Yes, the black thing that is at the base of the shaft. Mine didn't have a screw holding it in though, it snapped into a ridge on the right side of the distrubitor housing.

[RBNRaider]

Having simmilar prob with my 88 4.0 Mine starts but only when it wants to. After changing the distribuitor it started right up and again after shutdown. Did this about 10 times so I thought I got the problem. Next day again doesnt start. To day I changed some more (coil, module under coil, CPS) and distribuitor yesterday. I believe I have changed every ignition system component other than the computer and still no spark. I know that if I go out there in the morning it may start right up. Any ideas annyone?

[Carnuts]

Yes, the black thing that is at the base of the shaft. Mine didn't have a screw holding it in though, it snapped into a ridge on the right side of the distrubitor housing.

It looks like it wraps around the shaft. What year is yours?

[Carnuts]

Having simmilar prob with my 88 4.0 Mine starts but only when it wants to. After changing the distribuitor it started right up and again after shutdown. Did this about 10 times so I thought I got the problem. Next day again doesnt start. To day I changed some more (coil, module under coil, CPS) and distribuitor yesterday. I believe I have changed every ignition system component other than the computer and still no spark. I know that if I go out there in the morning it may start right up. Any ideas annyone?

Have you tested the starter relay mounted on the pass fender well? Didn't see it mentioned. Also the same thing langer1 mentioned. Test the camshaft position sensor. Just a thought since I have gone through the same mess.

[RBNRaider]

tested all connections to the dist and everything at ign. module, dist. and CPS and computer. The ign module is getting power but theres just no spark. But then sometimes it fires up but thats just cause it feels like it. Will check the starter relay.(one by the four relays with the mess of wires terminated on it?)

[Carnuts]

tested all connections to the dist and everything at ign. module, dist. and CPS and computer. The ign module is getting power but theres just no spark. But then sometimes it fires up but thats just cause it feels like it. Will check the starter relay.(one by the four relays with the mess of wires terminated on it?)

Yes. Has 4 prongs, and 1 post on it. The post has a bunch of wires including a positive batt cable. Our xj's have a mess of fusible lnks too if you have not checked them. Never know...

[RBNRaider]

Just looked at that. CPS is also new since it came in the new Dist. and I have also checked to make sure that the CPU and Ign. module are getting power. Is there a NSS eployed that would cause such random starts or maybe an ignition switch? My next step would be to check that module and cpu are getting power in both start and run positions. Still cant make sense of the randomness of the problem. Never had an issue with shutting down while running tho. That pointed me towards the sensors since with lack of signal from either it would just use the last one stored untill shutdown.

[Carnuts]

When I first bought mine it would run fine. Then I would stop at a store and upon going to start the engine it had no spark. This would only happen every now and then. I could wait 10 min or so and it woud finally start again. One day it finally quit starting. Replaced the CPS and no further problems. Well not until my current problem which I am still trying to resolve.

[langer1]

The CPS is back on the flywheel, the thing in the DIST is a CKP aka Cam Position sensor.
CPS for a XJ stands for Crank Position Sensor and fail 10 times more often than the CKP in the dist.

[RBNRaider]

Yup. so cam and crank sensors are new and still no spark. Ive kinda ran out of things to check. Makes me apreciate my 2.8 with webber carb so much.

[langer1]

The blue wire all by itself on the IG MOD is the trigger for spark. Check that for 5 vdc pulsing while cranking.

[RBNRaider]

The blue wire all by itself on the IG MOD is the trigger for spark. Check that for 5 vdc pulsing while cranking.

The wire by itself on my Ign. mod going into the middle jack (2 conductor) is a yellow wire. If no signal of 5v on that, what would be the prob?

Just so I know what direction im going in first thing tomorrow,

[Blaine B.]

That is odd, 3 (three) different stores had the part I described as the pickup coil, and when I picked it up it was the right part. Strange!

[Matthew Currie]

That is odd, 3 (three) different stores had the part I described as the pickup coil, and when I picked it up it was the right part. Strange!

Well, since it's in a distributor, and it's electronically pretty much a pickup coil (I think technically it's a hall effect sensor), that's probably how the parts stores describe it. I wouldn't be surprised if it could function as an ignition part in a different system. It just happens that in an XJ it doesn't do what you would logically expect it to do.

[RBNRaider]

My starter relay is lookin really bad so i wanted to change. The NAPA system has nothing listed under "starter relay" Annyone know of a part number I can track it down by? I'm unsure if this would cause a no spark situation. The cherokee also has something listed as an "ignition switch" that is just a metal bracket that a connector goes into (9 terminals on it) would this possibly prohibit the ignition system or ECU from geting voltage in run but not start?

[87manche]

that's possible.
The starter relay is OEM only as I found out.
I converted mine to a 4 pin light relay.

[RBNRaider]

thnx 87manche, I guess I could switch it to a standard 4 prong Ford type relay (current setup on my 84) Im just being cautious with mods untill I get this thing to spark again. Its geting rediculous

[Carnuts]

My starter relay is lookin really bad so i wanted to change. The NAPA system has nothing listed under "starter relay" Annyone know of a part number I can track it down by? I'm unsure if this would cause a no spark situation. The cherokee also has something listed as an "ignition switch" that is just a metal bracket that a connector goes into (9 terminals on it) would this possibly prohibit the ignition system or ECU from geting voltage in run but not start?

The relay is a Jeep dealer part that I found. At least that is the only place local that I could find.

[Carnuts]

Still no luck getting spark to mine.

If I lived in the country it might make an ok lawn ornament. I really miss
driving it though.

[Carnuts]

Ok. My XJ lives once again. The one thing I had forgot to check. The module under the coil on the pass fender. Go figure. Oh well. It's running again.
Thanks to those who tried to help.