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No spark. CPS???

Carnuts said:
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
Click to expand...

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.
 
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!
 
Carnuts said:
Pickup coil? The only thing I see under the distributor cap is the rotor. Then a big metal sheild.
Click to expand...

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.
 
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.
 
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 said:
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??
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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.
 
langer1 said:
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.
Click to expand...

Ugh. Had a feeling that was the case. I sent you a PM.
Thanks!
 
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.
 
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?
 
Blaine B. said:
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.
Click to expand...

It looks like it wraps around the shaft. What year is yours?
 
RBNRaider said:
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?
Click to expand...

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.
 
Last edited:
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?)
 
RBNRaider said:
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?)
Click to expand...

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...
 
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.
 
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.
 
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