sorting the iacv valve

[Engineer1949]

as the title suggests i have decided to get rid of the old stepper motor and fit a modern iacv valve, idea being for a start they are cheaper to replace plus far more accurate at sorting the tick over both when starting and when hot ,so got a lump of ally and started making up an adaptor block to fit the new valve to the plenum i have seen some bodged pipework arrangements so am trying to get it looking as if it should be there,just a couple of pics of todays progress should be all finished and fitted tomorrow
.


john

Untitled by hmstvr, on Flickr

Untitled by hmstvr, on Flickr

Untitled by hmstvr, on Flickr

[spitfire4v8]

I've never found the std stepper motor an issue .. just everything around it causes issues that people immediately assume are the stepper motor.
You're on emerald k6 yes? they control the std 4 wire stepper very nicely .. i always now leave them in when doing an ecu conversion as they work very well in reality I've found.

[carsy]

I dont have any idle valve at all and the Emerald manages tickover hot or cold no problem.

[SILICONEKID346HP]

Mine works lovely ... especially my cold start ..

[EGB]

Interesting this. Will replacing the Lucas Cux ECU with the Emerald solve erratic idle issues at hot or cold or at traffic light slow down, shunting etc, whilst still retaining the stepper, asuming the stepper is ok?

[carsy]

EGB said:

Interesting this. Will replacing the Lucas Cux ECU with the Emerald solve erratic idle issues at hot or cold or at traffic light slow down, shunting etc, whilst still retaining the stepper, asuming the stepper is ok?

In a word... Yes. And even more benefits such as getting rid of the afm and no more problems trying to get hold of rotor arms, caps, coils, amps that actually work.

O ye and better power and mpg. Its a win win.

[spend]

I don't get it at all?

If you want to ditch the stepper, just put a bung in the stepper hole and insert your idle valve in the pipe between the throttle & stepper housings, most even seem to be designed for in-line insertion in hose. Plenty have done it this way without any problems, although seems plenty leave the ugly stepper in place because they are too lazy to get a nice metric sump bung

[brett84]

Hey John
This guy sells brackets which bolt onto the rear end of the head and then you just need two straight pieces of silicon, if the design helps
http://www.megasquirt-v8.co.uk/ms_3-5_etc.php

[SILICONEKID346HP]

brett84 said:

Hey John
This guy sells brackets which bolt onto the rear end of the head and then you just need two straight pieces of silicon, if the design helps
http://www.megasquirt-v8.co.uk/ms_3-5_etc.php

Brett don`t forget to fit the air temp sensor where its cool ,mine is by the air filter .

[brett84]

I was just going to fit it in the same place as the AFM used to be? I thought yours was in the same spot?

[SILICONEKID346HP]

brett84 said:

I was just going to fit it in the same place as the AFM used to be? I thought yours was in the same spot?

You can get heat sink

[Engineer1949]

Thanks for the input the megasquirt offering is exactly what i dont want ugly plumbing with the valve between bits of hose looks very amateur each to there own i suppose.

John

[Pupp]

What valve are you intending to use John?

[MPoxon]

Engineer1949 said:

Thanks for the input the megasquirt offering is exactly what i dont want ugly plumbing with the valve between bits of hose looks very amateur each to there own i suppose.

John

I agree with that John I do not see the point of blanking off the original and plumbing in a few valve. The best and neatest solution would be to fit it where the original went.

Are you using the new IACV valve with the 14CUX or is this planned to work with an aftermarket ECU?

[Hoofa]

I run the stepper with motec, no problem whats so ever with idle, hot or cold start. In fact it can run without it if its mapped correctly and base idle. If it aint broke why fix it ?

Any cold or hot start problems are down to your map not the idle control valve unless it's knackered

Edited by Hoofa on Wednesday 14th May 19:52

[Hoofa]

I run the stepper with motec, no problem whats so ever with idle, hot or cold start. In fact it can run without it if its mapped correctly and base idle. If it aint broke why fix it ?

Any cold or hot start problems are down to your map not the idle control valve unless it's knackered

Edited by Hoofa on Wednesday 14th May 19:53

[blitzracing]

Id say the 14cux stepper itself is a perfectly sound design as long as you keep it and the chamber clean- most of the issues are down to wrong sensor inputs to the ECU, air leaks, misfires, wrong mixture. The ECU is programmed to expect the RPM to raise or fall in a preset manner as it control the airflow, so it makes a change - then waits to the idle to become stable before it applies any more correction. If The the shift in RPM is outside these boundaries the wait time can be to long and the engine dies.

[MPoxon]

Yes another good point, my 14CUX idle is perfect since the car was mapped by Mark Adams.