Username or Email Address
Do you already have an account?
Forgot your password?
  • Log in or Sign up

    VWVortex


    Results 1 to 11 of 11

    Thread: vr6 crankshaft position sensor problem

    1. 01-26-2007 02:11 PM #1
      Hello,

      the car is 1995 jetta vr6, and ive been working on it waayyy too long without getting any results. the problem i BELIEVE has something to do with the crankshaft position sensor. when the problem began, the car would take 3-10 cranking attempts to get spark and fire it up. it would start up completely randomly, when i would turn the key, it would either start immediately or crank as long as you hold it without starting. I decided finally to replace the CPS ($200), hoping it would fix the problem, but now it wont start at all. I tested the sensor resistance and it is good. I then got a multimeter and tested the (green) signal wire's output without it being plugged into the computer end of the harness, and it got signal when the engine was cranked, but when i tested it when plugged in to the computer end harness, i get no voltage reading, therefore no signal to ecm. how could just plugging in the sensor cancel the voltage?


    2. Geriatric Member need_a_VR6's Avatar
      Join Date
      May 19th, 1999
      Location
      Oxford, PA
      Posts
      35,596
      Vehicles
      03 325i
      01-26-2007 03:12 PM #2
      Sounds more like an ignition switch or an ECM relay problem.
      -Paul
      1995 GTI VR6 - Retired - 12.90@106 R32 power - 12.833@106 12v power
      KPTuned - Official MegaSquirt: Sales - Repair - Installation - Tuning
      MK3 Race Car Partout

    3. 01-26-2007 03:39 PM #3
      the ECM relay was recently replaced with the new gray cased one. as far as the ignition switch goes...are there any other symptoms of a bad switch that could help me rule it out/in as the problem? also note that the car ran(most of the time) before the CPS was worked on, now it doesnt at all.

      also i just took my multimeter and found out that on the computer side of the harness, both the green(signal) and black(ground) wires are grounded, voltage is produced when either one is used as ground. im pretty terrible when is comes to electronics, but wouldnt this explain why is get no voltage reading when the harness is plugged in?


    4. Member lazyace's Avatar
      Join Date
      Apr 16th, 2006
      Posts
      844
      Vehicles
      1995 VR6 Jetta, 1999 VR6 Golf
      01-26-2007 09:43 PM #4
      Well one symtom is that you loose your door charm and your radio wont turn on. Another is that it takes longer to start sometimes (cranks but does not start). Remember, you can have one symtom and not the other. You may try wiggling your key (also pushing and pulling in different directions) as you try to start. That usually works for a while.

      I would also try to find a buddy with vag-com to help you out (it would have probably ruled out your CPS.
      http://www.steve-hall.com/cgi-bin/VAG-Locator.pl
      http://www.frappr.com/vagcomlocator


      New ign switch is $5+ship from pap-parts.com

      http://forums.vwvortex.com/zerothread?id=2532481


    5. 01-27-2007 11:54 AM #5
      well..before i try replacing the switch, heres what it does.

      off - nothing (obviously)

      run (before crank) - power to running lights, air blower, lights on dash (check engine, battery, etc)...radio is hard wired so always has power and is turned on/off with button

      crank - engine cranks, but no start (one thing i noticed is when the car used to start, the ecm warning lights used to stay on when cranking, but now they dont)

      also.. did i make any sense with the whole CPS signal wire thing? does anyone know what could cause this?..or maybe it is normal somehow. i still think it is kind of wierd how the car started sometimes before CPS replacement, now nothing.

      another thing that im not sure could affect the car...the drivers side door got rained on a few times because of a non-working window..long shot i guess

      anyway thanks for the help so far guys


    6. Member lazyace's Avatar
      Join Date
      Apr 16th, 2006
      Posts
      844
      Vehicles
      1995 VR6 Jetta, 1999 VR6 Golf
      01-27-2007 06:56 PM #6
      I can't remember much about troubleshooting the CPS. I just figure vag-com would probably find the fault there. I can look in my bentley a little later today and get some info tho. Do you have your door/headlight reminder chime still installed? Does it work?

    7. 01-27-2007 09:01 PM #7
      replaced the ignition switch today using the forum link lazyace gave me...now the car starts like a champ. i paid $30 for it instead of 5 but i needed the car quick. i cant believe thats what it was- you guys are just as good as going to a mechanic.

      with that being said, the car has another minor engine problem (which I believe existed before)--the car has a kinda rough idle sometimes, and when i give it throttle and let off it cant seem to find idle- it revs up to as much as 2k, and then drops back down to appropriate idle (~700rpm) within 2 seconds or so. it does this in neutral and while driving and the clutch is pressed in. can anyone help me with that? this time i wont try to guess myself...doesnt work very well.

      thanks everybody for your good advice and willingness to listen


    8. Member lazyace's Avatar
      Join Date
      Apr 16th, 2006
      Posts
      844
      Vehicles
      1995 VR6 Jetta, 1999 VR6 Golf
      01-27-2007 10:13 PM #8
      That's great. As for your idle problem, I would first check for any loose connections or leaks on your intake then clean the throttle body. There should be a DIY in the FAQ section. Basically, you can take it off (4 allens) and clean it or clean it while on the engine. Clean with throttle body/carb cleaner or rubbing alcohol and gently wipe all grime and build-up away. Clean both sides of the butterfly valve. (Do not forget to give the cleaner ample time to dry, otherwise, fire)Make sure you don't get much cleaner on the throttle position sensor also. If you remove the TB make sure you torque it back down and use blue loc-tite. If that doesn't help, check for leaks in all vacuum lines (might as well just replace them all, 4mm). And if that all doesn't work, clean your idle stabilization valve.

      Look at part 2:

      http://forums.vwvortex.com/zerothread?id=1116399


      Modified by lazyace at 8:16 PM 1-27-2007


    9. 01-29-2007 06:55 PM #9
      "bump" for me... never used that word before...

      but anyway in regard to my idling problem, i figured out that the car is getting very poor fuel milage- no more than 15.5mpg. i assume that the injector pulse width is WIDE open due to some sensor problem.

      1- the car idle rough most of the time, and has a hard time finding the idle as i mentioned before
      2- when shifting gears, the car jerks pretty bad when engaging the clutch (yes i am good at driving it)
      3- slight loss of power

      ive done these things in a small hope to fix it with no results

      1- sea foam
      2- cleaned throttle body well (removed from car)
      3- checked O2 sensor - reads from 0-1v like normal
      4. air intake including filter is clean

      also...the car only started doing this after i replaced my crank position sensor and ignition switch

      any ideas from this new info?
      thanks


    10. 01-29-2007 08:22 PM #10
      should unplugging the MAF sensor noticably change the way the engine idles/runs? cause mine doesnt change

    11. Member lazyace's Avatar
      Join Date
      Apr 16th, 2006
      Posts
      844
      Vehicles
      1995 VR6 Jetta, 1999 VR6 Golf
      01-30-2007 05:02 AM #11
      It should run rougher when you unplug your maf. Can you find a friend with a maf to test swap? And any word on a vag-com scan? You can find out all kinds a good readings that would help you out.

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •