Westfalia.org Community - Powered by vBulletin

Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 40

Thread: ECU and electrical FI malfunctions

  1. #11
    Join Date
    Jul 2000
    Location
    San Diego, CA
    Posts
    13

    Default

    flypdx, thanks for the reply. I have yet to fix the problem, though I have done more troubleshooting. I currently have the god of vanagon parts at my local VW dealer working on getting me a new connector for Temp sensor II. It may be the problem, we'll see. What strikes me about the problem is the seemingly complete relation to engine temperature. It only occurs when the engine is fully warm, and then, only on warmer days. It never occurs on cooler days or during night time driving. Two weekends ago, I was on another trip when the problem occured. To test my engine temperature theory, I turned the heat on full force (to much whining from my traveling companions)just to see what would happen. After 10 minutes with the heat on, the problem stopped. I have tested this "theory" twice now, and both times, turning the heat on stopped the problem. This has led me to think that there is some temperature-related mess up in one of the sensors (or connectors). I may be going down the wrong path, but i ordered a new Temp sensor II even though the current one tests within bentley specs. I will replace that and the connector and see where that gets me. The van runs great otherwise, and the intermittent and temperature-related nature of this problem is pretty amazing. I'll keep you posted.
    BTW- does anyone know if I need to put any type of sealant on the threads for the new temp sensor II? seems like it wouldn't be necessary, but I would hate to create another problem by not doing so.....

  2. # ADS
    Adsense Circuit advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many
     
  3. #12
    Join Date
    May 2000
    Location
    Raleigh, NC USA
    Posts
    3,806

    Default

    The Temperature Sensor II uses an O-ring for sealing. Do not coat the threads with anything that is not electrically conductive as that is your ground point the sensor relies upon to complete the circuit. (You can usually coat the threads with WD-40 or silicone spray to ease installation without losing ground.)

  4. #13
    Join Date
    May 2000
    Location
    Raleigh, NC USA
    Posts
    3,806

    Default

    Computer glitch lost first part of message during board update.
    . . . For instance, the fuel guage would drop to zero. And sometimes the coolant light would begin to blink. But then these phenomena would disappear but the engine would still be erratic. Someone who has a different kind of vehicle said to me that the jerky performance happened to him when his vehicle needed a new timing belt. But I don't believe Vanagons have timing belts. Could this problem have been caused when the body was completly repainted several years ago? In other words, could an electrical contact been covered up? We love our Westfalia a lot and depend on it for summer vacations in Canada so we want to help it be better. Please offer any suggestions that I can pass along to my mechanic.

    Capt. Mike Moderator Member # 11 posted 05-27-2000 09:53 PM

    Simplest first, it is not a timing belt; the Vanagon waterboxer has none. It is not related to a long-ago repainting.
    Slight variations in idle -- hunting -- are a normal feature of the O² sensor controlled part of the FI system. O² sensors are a service item and should be replaced every 90,000 miles.

    The symptom you describe is closest to an erratic air-flow meter. The '85 will not have Vanagon Syndrome -- that's only on Digifant systems, but an erratic air-flow meter is possible on older models and will do that jerking at mid-range speed. You can test the air-flow meter with an ohmeter per the Bentley shop manual.

    That you are having erratic gauge and ignition controlled electrical problems indicates a deeper problem. The most common cause is a deterioration of the electrical side of the ignition switch. It is no longer feeding power to all key-on systems. Usually this will also show up in such other ignition-controlled circuits as headlights & wipers. This is a relatively easy & inexpensive item to change as it does not require changing the keyed ignition switch, just the electrical contact module.

    mjrly Junior Member # 74 posted 06-07-2000 11:50 AM

    My feeling is ignition switch as well, especially about the coolant light blinking. I bet it blinks about the same number of times as it does when you turn the switch 'on' before starting the engine.
    Let us know what your fix is if you can.

    Cheers,
    Matthew
    NC

    dwolterd Junior Member # 47 posted 06-08-2000 09:21 PM

    Thank you. I passed along your comments to my mechanic who has considered them but doesn't see an answer in them. He is, at this time, open to all ideas. He suggested that I use more detail in describing the problem and gave me these comments to pass along.

    "Here are the symptons:

    Engine starts and runs perfect when cold. After aprox. 2 minutes, engine will not run between 1000 and 2000 RPM's. As soon as Rpm's drop below 1000, it idles perfect and also if reved up above 2000. At this rpm range (1000 - 2000), I found that fuel injectors DO NOT get any pulse from ecu. It does not loose spark in this range. If coolant temperature sensor is disconnected, engine will run perfect at ANY rpm's. In 30 years experience as Auto Mechanik I have not seen anything like it, Your help is much appreciated! Laslo Bozoky.

    Work done so far:

    Coolant temp. sensor replaced; Air flow meter tested and replaced; ECU replaced; All ground connections cut back, and replaced ends; TPS replaced; Ignition Module replaced; Idle stabilizer box eliminated."
    These are his own words. Thank you for your initial comments and thank you in advance for any additional comments based on this better description of the problem from a mechanics view.

    Capt. Mike Moderator Member # 11 posted 06-19-2000 08:52 AM

    The Bosch FI has a dual brain setting for idle and for full throttle. It amounts to a transfer switch to change from the idle mode to the throttle load mode. A failure, including getting wet, can cause the engine to refuse to operate across that changeover range but be OK at the two extremes. Tell your mechanic to check the switches shown in circuits 10 - 12 in the Bentley wiring diagram. On the later water-cooleds it's located on the right side above #2 cylinder between case & head.

    It amounts to a transfer switch to change from the idle mode to the throttle load mode
    This switch is currently the subject of investigation. According to my mechanic, when replaced, the new one immediately failed. It seems to be getting 12 volts instead of 5. Currently looking at wiring harness at various spots to see where this wire it is tapping into battery strength current. Again, thank you for your helpful ideas on this subject.

  5. #14
    Join Date
    Jan 2002
    Location
    New Jersey
    Posts
    63

    Default

    Following the current diagram, it seems as though you may want to check the following:

    - if you are getting 12V (normal 4.5-6.5 per Bosch) it could be a couple of things:

    1) A bad resistor in ECU is over powering the switch, (you should have a "dual load" ECU on your Vanagon). See test circuit 10 per the Bentley guide.
    Note: I do not believe the 12V will 'fry' the switch, it will just provide a false reading.

    2) Grounds, grounds, grounds, grounds. Make sure everything is grounded.

    3) Temperature sensor circuit: Could be giving CPU false info due to a wire that has melted to something, rubbed itself and is now grounding out the circuit.

    My roll-up guess is that your temp. circuit has a fault in the wiring, albeit the MPC (plugs getting corroded). There may be a short, which will give the ECU a false command.

    or

    Bad ECU resistor letting too much voltage out the floodgates. (Test the resistance on the PINS per Bentley)

    In my experience, the ECU's are well protected and are pretty durable. There is also a relay (double) with a resistor and two diodes. The resistor operates the fuel pump correctly; the diodes keep the 'turn the key' current from running current, mostly when the intake air sensor kicks in and takes over.

    It's a long-shot, but check it out. Bad diodes would be relavant to the ECU, and sensors. The resistor just 'hands off' the fuel pump to the air sensor.

    Good Luck.
    Ron Wolff
    '76 Westy
    '78 SB Conv
    '74 SB Auto-stick

  6. #15
    Join Date
    May 2000
    Location
    Raleigh, NC USA
    Posts
    3,806

    Default

    Transferred to consolidate same topics.

    AC0T Junior Member posted January 31, 2003 01:31 AM

    Hello, I have a '84 1.9L DIGIJET with CA emissions.

    I just rebuilt the engine after 157k miles.
    Prior to the rebuilding I had some idling problems and poor gas milage (15 - 16 mph). I still have the problems now only worse.
    The engine always starts up easily, even in cold weather, but after it warms up and the Temp SensorII tells the ECM to slack off, it will hunt. And I don't mean 50 rpm hunt, I mean HUNT like 200 to 400 rpm, and generally run very rich over the driving range. Also when driving at city speeds it will occasionally buck (probable fuel shut off, but if I stomp on it and run up to hiway speeds it doesn't buck at all. It just doesn't have the pickup it used to have. (like it is running to rich) I checked all the FI components using my Bentley and everything checks out, with a few exceptions. Namely test #3 on the throttle valve switch, 24.33. When I operate the throttle valve switch by hand and slowly accelerate, the engine speed accelerates smoothly. This is just the opposite of what it should be. In fact, these conditions are reversed. It surges at normal warm idle and runs smoothly with the switch held closed and engine speed over 1500?? I then checked all the wiring back to the ECU plug and it was fine. I cut off and replace all the ground lugs and the lugs on the throttle valve and enrichment switches. No change

    So I bit the bullet and ordered a new "improved" ECU from the Bus Depot (025 90621E)
    After installing it I had a new problem. The engine would run for about 20 or 30 seconds, shut down and would not start up again. I found that if I turned the ignition off for 5 or 10 min. it would start up again, but again shut down after a few seconds. I found that after it stop running that I had spark but no fuel. I pulled the injectors off one bank and cranked it to be sure. Yep, no fuel. This new and improved ECU is shutting of my injectors. I reinstalled the old ECU and it fired right up and after it warmed up went right back to its shurging. I think this new ECU doesn't like the CA emissions?

    I guess my question is... What components comprise the CA emission system. How do they differ from the rest of the world and can I get rid of them??

    Thanks for your patience and sorry for the dissertation.

  7. #16
    Join Date
    May 2000
    Location
    Raleigh, NC USA
    Posts
    3,806

    Default

    Some possiblities:

    1. Excessive hunt can be caused by failure of the O sensor or its circuit and function to the ECU. O sensors have their own topic in this forum.

    2. That you can get past the bucking by full throttle may indicate a failure/misadjustment of the Idle/Full throttle switch. They have their own topic in this forum. Note there is a difference in Digijet versions per pg. 24.23 of the Bentley. Later models have throttle body with 1 switch.

    3. "New & Improved?" Says who? Go to your VW dealer and find the proper, current ECU for your CA vehicle on his fiche. A lot of aftermarket discount vendors buy whatever is cheapest and might work. I'd be surprised if VW and Bosch got together and designed a new & improved just for the CA market of a 19 year old vehicle. 025 90621E is not a valid VW number. Have you read the "Bus Depot" topic under PARTS? Ken Willard at Van-Again (PARTS forum) seems to have one of the better grasps of FI, ECU's, etc. Although he & I disagree on some facets of Vanagon Syndrome (not applicable to Digijet), I've found most of his advice pretty well right on. He carries one of the better selections of FI electronics.

    4. There are "Fuel Mileage" & "Surgin" topics in this forum that may provide some clues.

    5. By the time of advanced FI systems, the differences in CA and 49 are minimal. CA required 30K plugs so VW went to heavy-duty in all. Quite probably is a difference in ECU's as they program the entire engine management system. Many of CA's EPA differences are in evaporative and other emmissions, not necessarily the running electronics. Again (GUIDELINE #8!!) your dealer can be your best friend, just ask to look for the parts that are different in the CA version. In reality, you will probably be better staying with the CA version -- they differences aren't significant and you retain originality, and thus diagnostic continuity & parts compatibility.

    6. I notice you live in CO. Do include an check of your fuel. CO is NOTORIOUS for bad fuel. They have mandated some of the weirdest octane ratings I've ever experienced. There is a "Gas Octane . . " topic in the TIPS forum. I don't give a darn what 'grade' it says on the pump, R+M/2 must be 87! I found "regular" as low as 83 octane in CO and even middle grade below 87. My own Vanagon wouldn't run worth diddley when I put in a tank of their substandard regular by mistake.
    Last edited by Capt. Mike; 12-13-2008 at 07:13 AM.

  8. #17
    Join Date
    May 2000
    Location
    Raleigh, NC USA
    Posts
    3,806

    Default

    Transferred to consolidate same topic.

    CW Junior Member posted March 19, 2003 08:51 PM

    I am having a problem getting a new VOA engine running. After the engine was replaced by an independent shop now out of business, it ran several months (virtually no miles) then began quiting and refused to restart. Sit an undetermined period of time and after you worked on this or that would restart only to fail again unexpectedly. This required 3 rollback ventures home, one was 50 miles away. Not a happy camper. Two years have passed since it was done and last summer a VW dealer finally gave up telling us to convert to carburetors. I will not give up. One part resembling a relay - 4 wires plugged into it &(California only - no longer available)was defective, that is why we decided to change. We purchased a Federal ECU #280 000 178 to replace the original ECU #280 000 192. Fuel injection harness was changed from California to Federal and added items such as the resistor unit then deleted oxygen sensor and so on. Distributor is a factory rebuilt points unit #231 170 093. The air flow unit remains #280 200 020. How critical is the ECU unit being matched to the system? Is the air flow unit specific to each model ECU. And if the air flow unit is slightly out of specification when compared with Bentley's resistance readings in one catagory, would it keep the engine from running? Thanks for any help or thoughts.

    carlosthecatcatcher Junior Member posted March 20, 2003 05:24 PM

    probably not much help but the air flow meter on my 78 westy has the same bosch code as yours and i'm sure they must of made some changes over two years-if only to annoy everyone in the future.
    i've just had a LOT of problems with my injecion system but finally fixed them today (hurrah).one problem i have had and several friends is restarting particularly after a long journey, this turned out to be a poor connection in the red/black ignition wire due to corrosion 4 inches down the wire i.e not visible ! i would certainly doulble check out your double relay for any faults as most of my problems seem to stem from there.

  9. #18
    Join Date
    May 2000
    Location
    Raleigh, NC USA
    Posts
    3,806

    Default

    You deleted the O sensor? The '80 had an O sensor CA & Fed models.
    Last edited by Capt. Mike; 12-13-2008 at 07:13 AM.

  10. #19
    Join Date
    Mar 2001
    Location
    wallingford, CT
    Posts
    30

    Default

    HI Everyone. I am going to be installing a new ECU in my 1987 Westy Vanagon GL Hopefully this will be the answer to my problems Anyway, I wanted to know if replacing the ECU was just a matter of unplugging the old one(as shown on page 24.48 of the Bently repair manual) and plugging in the new one? (Disconnecting the battery first seems wise as well). The Bently
    as far as I can see doesn't provide any additional information. I guess it just sounds too easy. Thanks!!

  11. #20
    Join Date
    May 2000
    Location
    Raleigh, NC USA
    Posts
    3,806

    Default

    Sounds like a plan. Other than the "ignition off" warning, I haven't heard of anything else and have seen shop mechanics just swap EDU's out. The battery disconnect might be overkill, but that's better than ECUkill, huh? I have connected & disconnected one in a Type II without ill effects.

Page 2 of 4 FirstFirst 1234 LastLast

Tags for this Thread

Bookmarks

Posting Permissions

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