No spark.....same old story

I was wheeling my jeep last night and since i parked it it wont start.

I did put a hole in the radiator and there was all kinds of steam so I think I may have got something wet that shouldnt be. I checked the plugs and none of them are sparking.

I am getting 12-54-55 from the OBD codes. 54 is for the camshaft position sensor, however it is fairly new. The coil is also fairly new. I have never changed the crankshaft position sensor so it could be this. Wouldnt this show up on the OBD codes if it were bad though ?? Also is there any way to test the coil, cam position sensor and the crank position sensor ?

Not nessarily so, but if never replaced then it whould be worth the money to buy a new one and replace. need it to get spark at the plugs. Check coil by taking a plug and touching it to metal on the block , like a spark plug check. if no spark then most likly its your CPS. http://members.cox.net/wilsond/cps/
http://members.cox.net/wilsond/Fixes/diagnostics.html#CPSdetails

Well I did some searching around and found out that you can test the crank position sensor by checking the wire on it with a volt meter and it will go from 0 to 8 volts while cranking the motor over. By doing this i was able to determine that my cps is working properly. I also tested my camshaft position sensor the same way. My OBD is telling me the camshaft position sensor is bad...but it is producing voltage within the manuals specs.

I still am not getting any spark off the coil. I took the coil out and took to autozone and tested primary and secondary resistance beside a brand new one and they were the same....its a newer coil. I also checked the wire from the coil to the dist and it had 400 ohms of resistance which I thought was extremely high so I replaced it and still no spark off the coil.

I was lookin in the power dist box and saw a relay for an auto shutdown circuit. Could this be a possibility and what does it do if anything. If it is engaged is it necessary to turn it off or does it do it automatically. Also since theres a hole in the radiator...waiting on a new one....I dont have any coolant/water in the system since most of it drained out. Is there any sensor that may stop spark if theres no coolant ??

Thanks for all your help

no engine will still spark with no water in it. I would say replace you cps still. will not hurt any. As as far as the auto switch relay yes then something that controls power to everything so maybe check that out as well.

MiNi Beast said:

no engine will still spark with no water in it. I would say replace you cps still. will not hurt any. As as far as the auto switch relay yes then something that controls power to everything so maybe check that out as well.

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...The engine will still start with or without coolant water or whatever your using to cool it. It will just overheat then stop running etc catastrophic failure. Don't know where you got the idea that it wont run without water.

The ASD is used to reset the IAC valve on key off so its in the right spot for the next start. If this went bad it would likely cause a high idle on start. It would _not_ stop the vehicle from starting.

How are you checking for spark?

If you can, unplug any of the fuel injector connectors and connect its leads to a 194 bulb and check to see that it blinks (indicating ECM command injector open/close)

You didn't mention what year it was, since your pulling codes I'll assume atleast a 1991 but pre 1996?

It's possible to get a short in the CPS, that sucks down the five volt supply circuit. Check the five volt supply at the cam sensor the CPS and cam sensor share the same supply circuit.
When the CPS messes up, it will not let the fuel pump run except for a second or two prime when the key is turned to run. The fuel pump relay should close again as the motor is being cranked over.
The orange wire to the coil should have battery voltage anytime the key is in run or start. The coil triggers off of the ground side (gray wire) through the ECM ignition coil driver.
Filling the alternator with coolant can cause shorts. Coolant is a much better conductor than water.

Finally got the time to mess with the jeep again this weekend and heres where I stand.

I am checking for spark with a spark plug tester hooked up to the coil wire that would normally go on the distributor. This is a new wire.

After reading all the other posts on here about no spark I sucked it up and bought a crank position sensor and replaced it today and still have no spark.

As far as OBD goes I am getting a code 54 which is camshaft position sensor. This is a new sensor with less than 500 miles on it and I cant imagine it has gone bad already. I did the test for it with a multimeter and it was fine. I have cleared out the codes by removing the fuse in the power dist center and after a few cranks the computer shows this code.

Does anyone know which wire going into the computer comes from which sensors so that I could test if the signal is getting to the computer from the cam position sensor ?

I dont believe the issue is with fuel at this point unless something in the fuel circuit controls spark.

In the event that I did short something in the alternator wouldnt it at least run until the battery died ? In the past with other cars when an alternator went bad I could always get the car to run on jumpers and they would die a few blocks away when the battery could no longer produce enough spark. Does the alternator control spark other than re-charging the battery ?

Should I pursue the camshaft position sensor or replace alternator and or coil at this point ?

I have been in your situation several times, where I would get stranded for no effin reason, same no start scenario. hell I'd be driving and my jeep would just die. After many parts changed, and I mean everything, it turned out to be the little connector to the coil, apparently it just wore out, thats it. I even got another one for free at the local yard. I ended changing the PCM 3 X, Injectors, and the elec clips, coils, wires, plugs, cps, NSW, Distributor, cap, rotor, cam sensor, alternator, all wires at the alternator, and the relay box it self. And it was the freakin Lil connector. Go out and give it a looksy, I hope this helps.

Well, when my Jeep wouldnt start after parking it. It was the Crank Position Sensor. ('99 Limited)

I want to test the connector that plugs into the coil. There are two wires going to it: one black and another thats green and something else. I checked the ground with a test light and its good.

How can I test the other wire ? How many volts should it be and should they be constant or change as I try to start the truck ?

http://members.cox.net/wilsond/Fixes/diagnostics.html#CPSdetails

I replaced the Crankshaft position sensor and this didnt fix the problem. I want to test the plug that connects to the coil now.

same tool ohm meter to check it

I did some more testing this weekend and believe the problem is with the camshaft position sensor.

One wire on the sensor is a good ground.
The other provides a constant 8 volts
The third has a constant 5 volts when cranking over and with the key on,however it doesnt vary like i believe it is supposed to.

When I pulled the dist cap off and removed the sensor I noticed that the sensor has been rubbing the plastic notches on the metal interruptor that is underneath the sensor.

I also noticed that when the sensor is UNplugged, the 5v reference wire going to the pcm still reads 5 volts. Does this indicate a problem in the wiring since I am still getting 5v even when the sensor is unplugged ?

Also is there a diagram anywhere that shows which plugs going into the pcm correspond to which sensors ?

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I'd tend to believe your ODB diagnostic telling you that it's the cam sensor and or the wiring/connectors associated with that specific circuit.

Problem solved....after taking the distributor to autozone it became apparent that the problem was in the distributor. I dont know if a bushing went bad and ruined the sensor or what...but since this was a fairly new cam position sensor I decided to spend the extra 20 and just replace the whole distributor. Fired right up...Thanks for all the help especially the FSM