i have talked to a few people on here about this but havent gotten a direct answer and i was wanted some info before i start throwing money and parts at my 99! here is the deal. my check engine light came on and i had no rpm gauge the other day so i back out and took off then the rpm gauge started working again! i cleaned pcm and tps light went off went to town to get fuel took off mash the pedal and the check engine light came back on! and now the tach jumps up as u speed up instead of graudally going up when u speed up! well the other day i came home light still on shut off went back out to put some parts i had in the truck in the shop started her up she reved to 2300-2400rpms by herself and let out a huge cloud of black smoke then as soon as i was frantically trying to shut her down she stopped and went back to normal and the check engine light went off and hasnt came back on that was about a week ago! i still have the jumping tach! i was told bad crank pos. sensor? it doesnt feel like i have the power it did before this happend doesnt sound right either! just wanted some opionions before i start taring everything apart! thanks Andy

 

sounds like the CKP Crank Position Sensor...<br><br>DRecu!

 

mine wasn't acting quite as bad as yours but the tach jumped around, the truck surged, and occasionally would shut off when stopped at a light...it was the cps, not hard to change and not really expensive ( round $50)...good luck

 

thanks cattlehauler i checked ur pics and info and printed them off last week i was just seeing if it was the right simyptoms before i bought parts!! looks very simple to change with the pics cattelhauler took!!! i picked up the sensor today at the ******* for $56. thanks for the help fellas!! <br><br>what does the sensor actually do? Andy

 

the sensor &quot;reads&quot; the timing mark and sets the timing of the motor...VERY important sensor, when it goes it throws off your engine timing ( not good) ..anyway, let us know if it cured your problem and go slow when twisting out of the block...they can be stubborn! good luck..

 

ok thanks for the info! i bought the sensor like i said before but since it blew the black smoke cloud and reved to 2300-2400 rpms and then stopped and the light went off it has ran fine and the light hasnt come back on! what gives? i just dont understand what is going on really it runs like crap then its ok? im still going to change it hopefully this weekend! but this is still weird!

 

Powerwagon: It could also be an intermittent fault in the wiring of this sensor. You drive, move the cable loom around (vibrations, engine movements etc) and one time you got good contacts the other not. It's fun to search for troubles like these if they are not really close to the sensor. <br><br>HTH<br><br>AlpineRAM

 

finally today got the chance to change the sensor! very very easy tough part was top bolt on starter other than that 35-45mins in the driveway since shop is full of crap and the ocassinal walk to the shop for tools! ;D check engine light is still on so hopefully on the next few starts it will go off. i could tell right away that it was running better!!!! went down the road and performed great! stopped smoke the tires and parked her! yesterday went to town light came back on and truck about died twice!! and no rpm gauge at all! so i figured today was the day to change!! thanks to everyone with ur help!! and to cattle hauler for a very good pics, and details!! PW440