1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

truck dies

Discussion in 'Chevy Trucks' started by jdknight75, Jan 15, 2009.

  1. jdknight75

    jdknight75 Senior Member
    Messages: 106

    i have a 2002 Gmc with a 8.1 liter 496 every now and then my truck will die when driving. I dont think it is the battery because all the lights and radio remain on. If it dies when i am driving ive tried to put it in nuetral and start it but it will not fire. You have to stop and let the truck sit for a about 30 seconds then it will fire back up.
     
  2. CityGuy

    CityGuy PlowSite Fanatic
    Messages: 16,998

    sounds like it might be cap an rotor
     
  3. Rangerman

    Rangerman Senior Member
    Messages: 148

    He has no cap and rotor on that truck do u get a check engine light when it happens?
     
  4. jdknight75

    jdknight75 Senior Member
    Messages: 106

    no the check engine light does not come on.
     
  5. Bajak

    Bajak Senior Member
    Messages: 999

    Mine did the same thing. Fuel pump fixed mine, but I'm no expert.
     
  6. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The '01 and '02 model year 8.1's are well know for this rather intermittent issue. It's due to a defective crank shaft position sensor. Only affected the '01-'02...by '03 they got it right. :D


    And they're no fun to change. :realmad:
     
  7. jdknight75

    jdknight75 Senior Member
    Messages: 106

    B&B thanks for the help do you know what exactly that sensor does and why would it kill the engine?
     
  8. t.i.b

    t.i.b Senior Member
    Messages: 140

    to truck dies

    ive got the same truck just a chevy not gmc. shortly after i bought it it was dying like yours. i had the crank position sensor replaced and its been fine since. now ive got real wierd electrical problems. the cps went at 70000miles.
     
  9. t.i.b

    t.i.b Senior Member
    Messages: 140

    it acts like a disstributer, for timing and spark
     
  10. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The crank shaft position sensor (CKP for short) is used on engines with distributorless ignition systems, such as in most later model vehicles. The (CKP) sensor serves essentially the same purpose as the ignition pickup and trigger wheel in an electronic distributor once did. It generates a signal that the PCM needs to determine the position of the crankshaft and the number one cylinder. This information is necessary to control ignition timing and the operation of the fuel injectors as well as several other various functions that are overseen by the PCM. The signal from the crank sensor also tells the PCM the engine rpm so ignition timing can be advanced or ******** as needed. Most engines will not run without this sensor's input, as it's feed back is what most of all other info for the PCM's ability to control the various engine functions is based upon. The 8.1's are one of these engines...