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XJ NO START. New Parts. Please Help.

C

ColoradoXJ

NAXJA Forum User
Location
Copper Mtn CO
I have a 92 XJ 4.0L with starting problems. It started a month ago, when I was having cold starting problems. I replaced the fuel pump, and that fixed it. After a week or so, the engine wouldn't start until I heard the fuel pump kick on with ignition in the ON position, then it would start. I drove home from a 3 hour trip and now it will not start. Was running excellent when I got home and parked. Now the fuel pump never kicks on, nor am I getting spark. I have a new fuel pump, fuel filter, fuel relay, starter relay, CPS, TPS, and COIL. The fuel pump will pressurize the rail when I bypass everything with a wire to the resistor. The rail is presurized, but still no start. Is there some sort of senor/relay/computer that sends the signal to the coil to spark and fuel pump to pressurize the rail. I have checked my vaccum hoses and everything seems fine. I am a mechanical guy and this problem has got me at wits end.
 
ColoradoXJ said:
Is there some sort of senor/relay/computer that sends the signal to the coil to spark and fuel pump to pressurize the rail.
Click to expand...


I don't know about a '92, but on a '90, the computer tells the ignition module to charge and sends the spark to the ignition coil and then to the distributor. You might want to check out the module, if you have one?.
 
ONe possibility is the "cam position sensor" inside the distributor. When this failed on my stepson's 93, it seemed to interrupt the whole startup sequence, and nothing worked. You should be getting an engine code if this fails, but you might try unplugging this while the ignition is on, then replugging it. If the system then boots and the engine starts, there's your problem.

You might want also to check electrical connectors, and make sure the ignition switch itself isn't faulty.
 
I had a bad cps a week ago, my fuel pump worked fine, so it isnt your cps or coil. You did check fuses right? Good luck with the gremlin hunt!
 
Yes, I checked the relays. I don't think that my eithter of my fuse boxes have a fuse associated with those parts? I also have a ignition switch that is only 6 months old. The engine sounds great when it is turning over, it just will not start.
 
Mine is doing the exact same thing every morning. And I can't figure it out eather?
 
Does a 92 have a fuel pump ballast resistor located on the left inner fender? I know the older models do. And that could be the problem.
 
As I stated, I have a new Camshft Position Sensor or commonly called a CPS. Matt Currie and Kreutz were right on the money. Their wisdom lead me to a reboot. The fuel pump kicked on when in on/run position and the baby fired right up. Thanks alot guys. When I looked up the parts they both were the same just one is for 2000 and above? Another interesting note is that when it stays semi warm in the sun 80 +, even for hours, it works everytime. Also a common symptom for a fuel pump. Perhaps this was my problem all along. Thanks again.
 
So you judt turnef on the key then un-pluged the CPS and pluged it bavk in and away it went?
BTW anyone hace a good pic of the CPS on like a 1992 4.0L HO?
I just need to know what I'm looking for?
 
Be careful when saying "CPS". That almost always refers to a crankshaft position sensor. A camshaft position sensor is usually called...a camshaft position sensor.
 
The commonly refered to CPS is the troublesome Crank Position Sensor mounted in the bellhousing, NOT the Cam pos sensor located in the distributor...

Glad you got her running though!

Cory
 
I recently had similar problems on my 89 XJ. I discon and recon the cps plug, and it fired right up like nothing was wrong. The starter relay is also problematic as all the vehicle power goes through it. It has a rat's nest of wires and plugs going to it. I removed all of them and cleaned them and put them back on, looks like its working better. If you have an older rig like mine, you might want to replace it.

I would also put dielectric grease on the sensor plug connections and on other connections after cleaning. Keep water out and from corroding. I put it on the cps, idle air controller and the throttle position sensor. Seems to be running happier.

--Karl
 
badge714 said:
http://www.autozone.com/images/cds/gif/large/0900823d80152484.gif this shows the different sensors along with crankshaft position sensor on bellhousing and camshaft positionn sensor inside the distributor. hope this helps badge714
[email protected]
Click to expand...
That pic is good but it dosen't show the camshaft position sensor.
I guess it's the only wires going into the distributor right?
There is a conector just on the outside if the distributor, is that the one to unplug?
 
works great Thanx!
 
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