My van will start, idle kind of weird and die after I give it gas then let it idle again.

SKYMOTHA-DUCKINGWALKER

MEMBER
1984 VOLKSWAGEN VAN
200,000 MILES

I have a 1984 Volkswagen van. It has at least 200,000 miles on it. The problems first started when I let it run out of gas one time. It didn't start for about two weeks then I replaced the temperature sensor. Now it starts but it idles high then slows down and sounds like its about to die then idles high again and it keeps fluctuating like that. I changed the oxygen sensor yesterday and it seems like it idles a little bit better, but not much. After I start it and give it some gas the engine accelerates like it should but sounds like it is misfiring. When I take my foot off of the gas pedal the engine dies when it should return back to idling. I've cleaned the carburetor too, but that wasn't the problem. Also, there is a little orange wire on the left side of the engine compartment that came disconnected somewhere and there is some tubing on the end of the wire; I guess to hold it on to where it's supposed to go. One end goes around under the engine and the other side that came disconnected is supposed to go somewhere around the temperature sensor.

3 Replies

EXOVCDS

MECHANIC
1,883 POSTS

Post a picture of components that you are speaking of or have questions
about... your Van should not have carburetor, if it is a North American
model.

Air leaks are a common cause of idle issues... they can be easy or
difficult to spot.

A smoke machine can make it easy to find leaks:

http://www.youtube.com/watch?v=-V_W_SFxYoI&feature=plcp

Your van should have 2 throttle switches, Idle & WOT (Wide Open Throttle).

Make sure that the Idle Switch is closed when the Throttle is closed. #7 in this link:

http://www.benplace.com/vanagon_digijet_engine_component.htm

Your van is supposed to have an Auxiliary Air Regulator that allows
the engine to Idle high (1200rpm) when the engine is cold... the
valve is located below the # intake runner (where #8 is in the above
link).

When you look inside when it is cold, you should see an opening:

https://www.2carpros.com/images/external/DSC08026.JPG

As the valve warms-up, the opening closes... once closed, the engine
should have a normal idle, around 900rpm.

If your throttle screw is turned-in too far, then your warm idle
will not be correct.

Start with checking the idle switch, check for any broken vacuum
hoses, make sure that the Ignition Timing is correct (disconnect & plug
the Idle Control Module between the ignition coil & Ignition module).

Take a fuel sample from the fuel filter (shake the filter and
dump the fuel in a glass jar)... look for rust, water. If either
is present in large quantity, remove the gas tank & check for the
cause.

Thomas