G60 ISV woes..

[7onny 0]

Hi.

My 92 g60 hunts and bucks around when the ISV is plugged in, iv taken it off and cleaned it and soaked it over night in carb cleaner, and its made no difference. However, if I unplug it, it idles fine and drives as it should. So, for the past few weeks iv driven without it plugged in (but still in place). Iv borrowed a known working isv off my mates golf g60 and i have the same problem of hunting, and iv tried my isv on my mates car and its fine! I'm now wanting to get a chip and pulley kit and wondered if the new chip wouldn't like the ISV being unplugged. Could someone advise me on how to solve this problem or if its fine leaving it unplugged.

Ta - jonny.

[Supercharged 2]

Get it running right first before you chip it...

 

Are the throttle micro-switches working ok and the cable adjusted properly? The idle switch is what activates the ISV

[7onny 0]

The switches seem fine but I'll double check, the throttle cable is a little slack to be honest, but could that affect the operation of the isv?

[Matt@OCD 0]

With your tests you've proved your ISV is fine but something else isn't.

 

As said check the throttle switches, both WOT and closed, both done at engine idling.

 

To test WOT just press the little switch and revs should increase slightly, enough to hear engine tone change, for closed just lift throttle off of idle by hand a little so revs pick up and you can then press the idle switch, revs should dip back down.

 

Then just be sure the throttle is pressing on the switch when returning to idle, it's common for the switch to move a slight amount over the years.

 

If these are both fine I'd look at testing the wiring from the ISV plug to the engine ECU, disconnect the ECU plug with ignition off and test the resistance (ohms) across pins 14&22 (you might have to take plug apart to find the numbers) then check continuity on ISV plug pin 1 to 14 and pin 3 to 22, I think you might have a broken wire, pin 1 should receive 12v with ignition and ECU plugged in too

[7onny 0]

Thanks for that Matt. I'll have a look into that today and let you know.

[7onny 0]

Right Iv checked the wot switch and it doesn't seem to change the engine note. Does it ignore the wot switch if it's not fully up to temp. As it had only been ticking over for about 5-10mins when I checked.

[Matt@OCD 0]

No, should work all the time, just try it with the cable just off idle so it's not getting a signal from closed switch too

[7onny 0]

Ok I'll try that in the morning and let you know.