Cam Position Sensor

[douge36]

What is it's primary function? Does it control the strength of the spark to the plugs or merely tell the PCM which cylinder needs spark? What controls the strength of the spark. Reason: My spark is a dull yellow/red. My coil checked out on a test. My cap and rotor are new. CPS is new. What else controls spark intensity?

[Dale Aeppli]

the camshaft sensor works inconjuction with crankshaft sensor to tell pcm when to fire #1 cylinder. your coil should a blueish in color Dale

[douge36]

It should be blue but it's not. The coil tested ok so and the parts store tried to sell me the cam position sensor as the probable cause but I don't think that has anything to do with my weak spark.

[Dale Aeppli]

If the camshaft sensor goes bad the vehicle will not start till it's changed. The crankshaft sensor goes bad it will usually start after cooling down. I'm guessing the jeep will start but has weak spark, is this right Dale

[douge36]

Exactly, it will start and idles fine except for the fuel mixture. I believe though that once I find the sprk problem the fuel mixture wont be a problem. None the less I took it to the Jeep dealership to get an answer. I'm tired of throwing parts at it.

[douge36]

Well the news came back from the Chrysler dealer today. They don't know what's wrong with it. They want to pull the engine and see if they can find the problem. Seems to me that's like removing a leg to fix athletes foot. They said all of the sensors checked out ok and the computer checked out ok and they think it's something mechanical. Well of course I told them no way. I'll get it figured out.

[bringselpup]

What about wires? Do you have a spare plug wire anywhere so you could swap the coil to the top of the cap? Maybe corrosion in a connection somewhere ahead of the coil keeping it from delivering a full shot?

[douge36]

OK, update- Jeep fixed. Chrysler of course had no idea what was wrong with the thing. They had it for 3 days and found nothing wrong. I took it to an independent mechanic and come to find out I had 90lbs of fuel pressure at the rail. That was with a new fuel pressure regulator. apparently my return is blocked and the fuel is not getting back to the tank. That would explain the tank of gas I used in a week trying to diagnose the problem. Also I bought all of my parts new at Auto Zone and I'm not bashing Auto Zone because the parts were not their brand but both the TPS and the FPR I bought at Auto Zone were defective in the diagnosis. Hopefully they'll return my money or give me a store credit.

[douge36]

The mechanic said that the roll over check valve on the pump was bad. They took the check valve off and now it runs fine. For all with their ideas and help, thanks much.