ISV Clicks but no buzz

[Alex Mckenzie]

Hi VW kings & Queens

I know there is a lot of articles on this but I haven’t found one with my pacific issue(or maybe I just can’t read).

Issue = bad Idle until the engine is hot. (conks out all the time)

Suspect – ISV.

The Isv is not buzzing with the ignition on, although when I turn the ignition it make a single click, then nothing. Could not tell if it is buzzing while the engine on due to all the other vibrations and noises.
I have a spare which also dose the same thing.

I did clean them with throttle body cleaner, Has this killed them ? or could there be another cause for the issue.

Any help would be great.

Ps anyone know where I can get the CO set in the Brisbane area ?

[h100vw]

Hi VW kings & Queens

I know there is a lot of articles on this but I haven’t found one with my pacific issue(or maybe I just can’t read).

Issue = bad Idle until the engine is hot. (conks out all the time)

Suspect – ISV.

The Isv is not buzzing with the ignition on, although when I turn the ignition it make a single click, then nothing. Could not tell if it is buzzing while the engine on due to all the other vibrations and noises.
I have a spare which also dose the same thing.

I did clean them with throttle body cleaner, Has this killed them ? or could there be another cause for the issue.

Any help would be great.

Ps anyone know where I can get the CO set in the Brisbane area ?

Only from memory but there is an idle adjustment on the throttlebody, which is set by disconnecting the water temp sensor and revving the engine 3 times. This fixes the ISV to make the adjustment. This is the same time you adjust the ignition timing.

I wonder if there is a problem causing those set up conditions to be met all the time. Bad wiring or something maybe?

Even without the ISV the engine should be capable of idling on it's own.

Gavin

[Alex Mckenzie]

Thanks Gavin

I can get the engine warmed up, do the ecu reset and set the idle, but when the engine is cold, it won't idle, it just dies, until I get it warm

[ryana89]

When the engine is cold, if you hold the rpm above idle (say 1500) what does the engine do?
Also have you felt the ISV with the engine running? If its running you can feel it vibrating.

There are switches on the throttle body that tell the ECU when throttle is at idle or WOT..... just a thought

[Alex Mckenzie]

When the engine is cold, if you hold the rpm above idle (say 1500) what does the engine do?
Also have you felt the ISV with the engine running? If its running you can feel it vibrating.

There are switches on the throttle body that tell the ECU when throttle is at idle or WOT..... just a thought

the engine stays steady when controlling with accelerator pedal.
I think its vibrating, it feels like it is, but not sure as may just be engine vibration.

I'll check the throttle body, see if i can locate the switches, can you advise what i'm looking for ?

[ryana89]

Digi can be such a wild goose chase...

In regard to the switches,


Although your symptoms don't seem to match that...

When was the last time your replaced your Blue temp sensor?

Also, this thread always helps me,
The uber DIGIFANT thread

[Alex Mckenzie]

thanks for the info.
Update. she idled fine in the afternoon ( still cold, been sitting for 8 hours) but this morning back to her issues. I'll check the switch.
ps blue temp switch was replaced about 900klm ago. looks after market, so may also be part of the issue.

[robiom]

Hey Alex,

Could be the vacume hoses if there perished or there is a leak....

worth a check.

[h100vw]

Swap the plugs on the blue and black sensors and see what that does from cold. If it runs better and the temp gauge plays up, the blue sensor is toast.

Closed throttle switch could be a problem. There must be a diagram of that in the Haynes. You can check it with a multimeter.

Gavin