DanChave's Flash Red GTI 16V. Engine strip, clean and paint!

[tshirt2k]

The ISVs are pwm controlled so you shouldn't be just connecting power to them like that.

You can check there's power to them by testing voltage between the black wire and earth. That wire is fused at the fuseboard. The white wire goes to the ecu to use as the control.

If the isv was stuck open, you would have a very high idle. Have you checked the operation of the idle switch on the TB? Are the wires going to the TPS in good nick?

[DanChave]

Yeah well I know that now  there is voltage at the ISV plug, checked the throttle switch and TPS wires, all three of the TPS wires were knackered and I had new sections soldered in. Picked up another ISV today, fitted it and still no difference. Then we adjusted the throttle cable so the it was as tight as it could be with it still depressing the switch, and we got it to idle, although now it hunts between 400 and 1000 before settling on 900 rpm on start up and it will dip down to 400rpm when you take your foot off the accelerator until the engine is over 2000rpm then it is quite stable. As soon as youare moving slowely and there is heavy braking will it start hunting again and occasionally enough to stall!

[Bellend]

Is there air leaks or blocked pipes somewhere?

What's the throttle body like? Clean?

Is all the carbon canister still there? Pull an air pipe off and see how it runs then. Should idle stupidly high but try it.

[Bellend]

Just seen the last post. If you are adjusting the cable so it idles it's only masking the issue. It should idle with no throttle cable.

[DanChave]

I'll have a look at the carbon canister tomorrow. I know adjusting the cable will mask the problem, but at least it is now drivable! I have a pair of ISVs soaking in petrol overnight, I will try them both tomorrow as I'm pretty sure it is an ISV problem. Once the car was up to temp it would idle fine, and pulling the breather hose off from the ISV to the airbox and blocking it would starve the engine, which the other two wouldn't do. I guess they are both stuck closed whereas this one is a little bit open but stuck.

TB is clean as a whistle and all the breather pipes have been checked for splits and blockages and all the vac lines have Been replaced with 3mm ID silicone hoses.

[Bellend]

I'll have a look at the carbon canister tomorrow. I know adjusting the cable will mask the problem, but at least it is now drivable! I have a pair of ISVs soaking in petrol overnight, I will try them both tomorrow as I'm pretty sure it is an ISV problem. Once the car was up to temp it would idle fine, and pulling the breather hose off from the ISV to the airbox and blocking it would starve the engine, which the other two wouldn't do. I guess they are both stuck closed whereas this one is a little bit open but stuck.

TB is clean as a whistle and all the breather pipes have been checked for splits and blockages and all the vac lines have Been replaced with 3mm ID silicone hoses.

Is the distributor timing bang on? Unlikely but could be possible.

Try pull the vaccuum pipe off the carbon canister. Should idle high.

[tshirt2k]

Did you take TB apart at all?

[tweed]

Have you changed relays yet?

[DanChave]

I'll have a look at the carbon canister tomorrow. I know adjusting the cable will mask the problem, but at least it is now drivable! I have a pair of ISVs soaking in petrol overnight, I will try them both tomorrow as I'm pretty sure it is an ISV problem. Once the car was up to temp it would idle fine, and pulling the breather hose off from the ISV to the airbox and blocking it would starve the engine, which the other two wouldn't do. I guess they are both stuck closed whereas this one is a little bit open but stuck.

TB is clean as a whistle and all the breather pipes have been checked for splits and blockages and all the vac lines have Been replaced with 3mm ID silicone hoses.

Is the distributor timing bang on? Unlikely but could be possible.

Try pull the vaccuum pipe off the carbon canister. Should idle high.

The dizzy on these can only go on one way dude, and there is no adjustment! I'll try the carbon canister tomorrow

[DanChave]

Did you take TB apart at all?

When I took the TB off I also removed the TPS  and idle switch but that's all....