91 GC Vacuum?

Discussion in 'General Motoring' started by dprkk, Jul 16, 2006.

  1. dprkk

    dprkk Guest

    What is the typical vacuum spec for a 91 grand caravan? My scantool
    read around 8.8 - 9.0 inches at idle. Does this seem low?
     
    dprkk, Jul 16, 2006
    #1
  2. dprkk

    maxpower Guest

    You have to have at least 17 inches of vacuum at idle or the map sensor
    thinks the engine is under a load and dumps allot of fuel causing a very
    rich mixture at idle
    Start with checking the EGR valve

    Glenn Beasley
    Chrysler Tech
     
    maxpower, Jul 16, 2006
    #2
  3. dprkk

    dprkk Guest

    Thanks Glenn. I just bought a scantool and am studying the Haynes
    "OBD2" techbook. I don't have any DTC's at the moment and the car seems
    to be operatring ok, but I did notice that the vacuum seemed low. I
    will start testing the EGR system.

    Ken
     
    dprkk, Jul 16, 2006
    #3
  4. dprkk

    aarcuda69062 Guest

    What PID is giving you 8.8-9.0 inches, is it MAP or vacuum?

    What is the MAP voltage?
     
    aarcuda69062, Jul 16, 2006
    #4
  5. dprkk

    dprkk Guest

    It is definitely vacuum. I didn't note the MAP voltage but I will
    check it all out tomorrow.
     
    dprkk, Jul 16, 2006
    #5
  6. dprkk

    maxpower Guest

    If you are only reading this off of a scan tool you better connect a
    mechanical vacuum gauge to the intake manifold. If you are going to connect
    it to the map sensor line you have to tee into it and not disconnect it.
    If you only have 8 inches of vacuum at idle the engine should be running
    like crap and possibly pushing black smoke out of the tailpipe.
    Your scan tool is probably reading Barometric reading. Take a look at the
    sensor value. I bet the sensor voltage is around 1.4volt at idle
     
    maxpower, Jul 16, 2006
    #6
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Similar Threads

  1. Vacuum check valve replacement item

  2. possible vacuum leak, need help

  3. NOS Vacuum lines for 1968 Charger Headlight doors.

  4. B/RB vacuum advance source?

  5. 1994 Chrysler Concorde downshift problem.(air vacuum sensor?

  6. Voyager vacuum leak solved.....

  7. No vacuum to heater core valve - 1991 GC

  8. Vacuum heater valve 91 GC

Loading...