ABF conversion. ISV and idle problems

[Mr Blue]

Hello mk3'ers

Did a search but no clear answer.

I have a mk1 with an ABF conversion running ABF management.
It doesnt idle. Engine does run but just the idle is a problem. (cuts out)

The ISV does not buzz. I have no 12v at the ISV plug.

What should I check now?


thanks

[Mr Blue]

checked the ISV, check the throttle switch for ohms, checked the throttle position sensor,
checked all earths and wiring with no visible faults.

Still getting 0.4v at the ISV plug which i have been told it should be about 5-7v.

Could this be the ECU relay? number 30.

The relay 167 is fine and has been changed.

[Len]

Doubt very much its the ECU relay.

Have you checked all the vacuum hoses?
And engine breathers?

[justalex81]

turn key to first position and isv should hum/buzz. If it isn't then that's the first thing to look at

[MK3GTI_16Valve]

not all buzz from what i read before.....

[Mr Blue]

I have checked all vacume hoses and everything is connected.
The breather pipe that comes off the square box is not connected to anything. Doubt this is the problem.

Replaced ISV for a new working one.

I get 0.4 v at the ISV plug. The idle problem is due to the isv not buzzing.

I also have no readings from the coolant temp sensor (two green wires)

Is their a relay for the ISV?

[Mr Blue]

Sorted now. Thanks all the input.

Turns out the White ISV wire goes to the ECU pin 27

Black ISV wire has now been fused to 12v ignition live.

All idle problems sorted and isv working 

[Len]

not all buzz from what i read before.....

Mine does NOT buzz! Had my car for 7 years and it idles fine!

[justalex81]

like i said before len its probably stuck open at the right position 

[Len]

I wouldnt want it to buzz now!

And anyway I guess I wont be having one when the ITB's get fitted!