Proper Idle Switch Adjustment

Many folks call me with the complaint that their Vanagon is not idling properly. Either they are idling too high or too low (stalling) or the idle isn't steady. There can be several factors that contribute to this problem however most of the time the culprit is an out of adjustment idle switch on the throttle body. This switch is located below the throttle body on 85-92 Vanagons and most folks don't even know that it exists. However if the computer is looking for a signal from it and is not seeing it, then it thinks it that the van is still driving down the road and not sitting at the light. I am going to give instructions for inspecting and adjusting this switch for 85-92 Vanagons.

Go to the rear of the van with the engine not running. Remove the engine lid and set it aside. At around the middle of the engine compartment you will see the throttle body attached to the metal air distributor for the intake. Use your fingers to move the throttle arm on the top of the throttle body from where it is at rest (idle position) to the full throttle position (as far as you can move it). Right when you are getting to the full throttle position you should hear a small "click" noise. Now slowly move the throttle arm back to idle position. Right before you get to this position you should hear the same small click. If you don't hear it then the switch is out of adjustment. If you hear it then test the switch for continuity with a multimeter. It should have zero resistance at idle and full throttle position. If it doesn't then you need a new one.

If you need to adjust the switch, the easiest way to this this that I have found is to remove intake boot and the two phillips head screws that hold the throttle body to the intake. Flip the throttle body upside down. Now you should see a black plastic cover that goes over the switch. Pull it off and set it aside. You will see the metal arm of the switch that rides up against the plastic cam that actuates the switch. The end of the arm is in the shape of a "U". Use a pair of needle nose pliers and tweak the end of the arm. You want to bend the part of the "U" that touches against the cam so that the "U" is just a little bit wider than it was (not a bunch, just a tweak). Now flip the switch over and try the test again. Tweak the "U" until the switch works properly at idle position. Now put everything back together and start the van. It should idle properly at around 950 rpms.

Some folks try to work around this problem by raising the rpm or unplugging the idle stabilizer valve on the center of the engine. If you notice this valve unplugged, plug it back in. If the RPMS are still too high you might want to check your timing with a timing light. If the timing is on the money (7 degrees BTDC) then adjust your rpms down by turning the idle air screw (large slotted screw on the top of the throttle body) in a little. Count your turns so that you can put the screw back to where you had it originally if you find your real problem isn't this screw.

If you are still have a problem with your idle after doing all of this then either your idle air stabilizer valve or the idle control unit are faulty. I would try cleaning the valve with carb cleaner and see if this helps. If not then swapping in a known good idle air valve or ISCU would be a great way to troubleshoot this problem. If known good ones aren't available to borrow then you just need to flip a coin and decide which of these two expensive parts you want to try to replace first. Smell your ISCU (located behind the tail light on the passenger side. If it smells burnt then it probably is and needs to be replaced. I know they are expensive but having a properly functioning idle control circuit is important to keep your van running well, cut down on fuel usage, and keep the van from stalling when using the A/C or turning. Email me and let me know if this write up helps you with this issue.

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Clearance

Fall is also a great time to get some great deals on parts here at Van-Again We are looking at some parts that we have had sitting around for a while that would probably have a better home installed on your van and we are slashing prices to get them there. Here is a list of things that are close-outs and specials that is only being advertised through this email list:

Brown sliding door interior panels for all Vanagons 84-87 with brown/tan interior.- $199 (SOLD)



Performance Digijet ECU- $250 (1 left) This ECU is a brand new VW unit that was made for 2.2l water boxers that were sold in Europe. It has a more aggressive fuel map which should give you some more power out of either a 1.9l engine or a larger water boxer that is using the Digijet fuel injection system. This system was used in 83.5-85 1.9l Water boxers only here in the US.

Vanagon front heater core- $199

Diesel VW Rabbit/Jetta/Vanagon Fuel Pump (brand new)- $695

We will be updating and changing our list of clearance parts as we sell things and stumble across other items. Since these are clearance items they are NOT available through the webstore. Email us or call if you are interested.

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