Off topic "jeep"

[popeye13433]

Hey i know its off topic but maybe some one can help me out.

anyone have a 1993 to 1995 jeep grand Cherokee 4.0 L that can take a voltage reading across the pins of their camshaft pick up sensor. cant find the readings that are for a running jeep and my manual hasnt showed up in the mail yet. and im not getting any answers on the jeep forum

thanks
Bobby

 

[konarider94]

im pretty sure they didnt have camshaft position sensors until ~the year 2000. Im pretty sure my 94 XJ did not have one. They relied on the crank position sensor. I can check my factory service manual when i get home. edit (yes they do but they are different than the distributor less jeeps.) i remembered a difference but ive been out of the jeep game for a while. ill check my fsm when i get home, it should list the testing procedure.

Check this out for the crank position sensor testing procedure.
http://www.jeepforum.com/forum/f11/normal-voltage-crank-position-sensor-cps-1294313/

 

[popeye13433]

It not referred to as a camshaft sensor the parts manual calls it an ignition pick up but serves the same purpose. its actually the sensor mounted under the dis. cap. I ran across that forum you posted and the Crank sensor tests good. i was hoping that was my smoking gun but no luck. Thanks for the info. this is my first jeep my wire chasing is pointing me toward the PCM i hope not, it will make this cheep purchase mighty expensive.

 

[konarider94]

It not referred to as a camshaft sensor the parts manual calls it an ignition pick up but serves the same purpose.

yea thats what threw me off at first. on the later 4.0L they went to a sensor that actually mounts on the camshaft. ill check my fsm later(ill try to anyway..poker game tonight) about the testing procedure for that pickup coil though.

 

[popeye13433]

Thanks for the help good luck at your poker game

 

[rshepler217]

up till 2000 they did have a camshaft sensor but it was in the ignition pick up in the distributor. they are common for going out and shortly after that the crank sensor usually goes.

 

[konarider94]

up till 2000 they did have a camshaft sensor but it was in the ignition pick up in the distributor

i think we established that already.

Thanks for the help good luck at your poker game

lost 10 bucks...feel free to donate 10 bucks to my paypal if you find this information worth while.

 

[firefighter1c57]

I got it, you said the crank sensor tested good... Change the crank sensor, yes I know it tested good... change it anyways... I'm telling you, change it and it'll run fine... Just change it... Yes it tested fine, they'll do that and still be bad, especially if you tested it with it cold. Yes, I know you tested it with it warm. I've been thru 5 different Jeeps in the last 10 years. Chrysler specificly engineered them I think, so that the cam sensor would last forever, but the crank sensor goes bad since it's at the top of the bell housing under the firewall at the top of the transmission and the only way to get to it is with three feet of extensions and then the bolt like to drop down in the bell housing hole while you are trying to install the new one... I think, due to the proximity of the exhaust manifold, and the high heat the 4.0 was engineered to run at to meet emissions standards, the sensors go bad more often...




Told ya...

 

[popeye13433]

It very well could have.

 

[popeye13433]

Thanks for the info the cam pickup was bad got new one installed today now she fires right up and dies just as fast. I have my factory service manual so off for some more troubleshooting. And yes i will check out a new crank sensor.

 

[firefighter1c57]

if the two sensors do not agree with each other(condition called hall effect, or hale, I don't remember) it will not run. Change the crank sensor. I'd imagine, after you change it, you can reinstall the old cam sensor, and it'll still run fine.

 

[popeye13433]

Thanks again guys i actually had two problems may have been caused by one another. first i had the bad camshaft sensor. second i was having a PCM issue. the PCM was giving me a logic check engine light. i installed a second ECM and now she purrs like a kitten.