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Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 9:23 am
by Nzer
'quipt4it wrote:With the camshaft, 2 degrees less in lobe separation is fairly significant in terms of vacuum and hence idle quality.
However, the situation is not that bad if the memcal suits. Stick that 3mm orifice in there and let's see what gives.
Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 9:41 am
by 'quipt4it
That o-ring is pinching and is in the wrong spot.
Refer to the link re-IAC's I sent. page 8
Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 10:03 am
by 'quipt4it
Don't re-use it. You'd be better off using a proper o-ring in place of that soft-ass POS.
Likely leaking as well.
Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 10:18 am
by Nzer
'quipt4it wrote:Don't re-use it. You'd be better off using a proper o-ring in place of that soft-ass POS.
Likely leaking as well.
Yea it’s not the IAC in the photo but that is the style I have.
I’ve tried 3 different gaskets now and is not doing that well. I’ve stuffed around with screwing the throttle stop screw and adjusting the TPS to have the voltage down. At start up it throws up to around 1500rpm and the IAC slowly stops bleeding until it stalls.
It will idle around 1100-1200 but as soon as i try to bring it down it will hunt to a stall.
Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 10:27 am
by 'quipt4it
Are any of the different sizes making a difference in idle speed or are they all the same speed.
If all the same you would have to go smaller than the smallest one you tried.
Remember the thickness issue I mentioned. How thick are the plates.
Your trying to bump idle up with the screw, not down.
Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 10:43 am
by 'quipt4it
Is that a spare IAC then?
Just for sh1ts & giggles, throw that one in there
Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 10:46 am
by Nzer
'quipt4it wrote:Are any of the different sizes making a difference in idle speed or are they all the same speed.
If all the same you would have to go smaller than the smallest one you tried.
Remember the thickness issue I mentioned. How thick are the the plates.
Your trying to bump idle up with the screw, not down.
What is happening is.
I start it. The revs throw up to 2000rpm. Sits there for maybe 5 seconds. Then the IAC starts to close and the revs drop to around what we want normal idle to to 750-850rpm. Then it hunts and stalls. The IAC is barely open. So at idle the IAC is hardly open which I thought it would be with the TPS voltage reading low so it thinks it’s in idle mode.
I’ll go back to the 3mm hole and try again.
Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 10:47 am
by Nzer
'quipt4it wrote:Is that a spare IAC then?
Just for sh1ts & giggles, throw that one in there
I had it in there but have done back to the genuine one. Just switched o-rings off the genuine one. I’ve left the orange one on their to remind me.
Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 10:49 am
by Nzer
Who’s idea was it to build a VL Walkinshaw. Oh fuck that was my idea!
Re: VL Walkinshaw High Idle Issue
Posted: Thu Dec 17, 2020 10:49 am
by 'quipt4it
If you've already tried it, go smaller.