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stepper motor - alternatives

Posted: Sun Sep 08, 2019 6:10 pm
by Seight-V8
hello all,

If I wanted better idle control on my Rover v8 GEMS 4.6 engine, I presume I would do away with the stepper motor in the throttle housing.

But what valve would be in its place and how would it be plumbed?

I'm running a gems 4.6 with a modified throttle plate to act westfield plenum, and a VEMS ecu.

cheers
scott

Re: stepper motor - alternatives

Posted: Sun Sep 08, 2019 6:31 pm
by ChrisJC
You are going to have to explain your thinking a bit more. The stepper motor is controlled by the ECU to maintain idle speed. So if you do away with it, there will be no idle speed control at all!

Chris.

Re: stepper motor - alternatives

Posted: Sun Sep 08, 2019 7:18 pm
by Seight-V8
sorry, just wondered if there's anything better the stepper motor I currently have.

I see the thor engine has a bosch 2 wire valve, would this be any better, or am I just going up the garden path so to speak.

just a train of thought I currently have.

thanks
scott

Re: stepper motor - alternatives

Posted: Mon Sep 09, 2019 9:05 am
by DaveEFI
I have a Bosch PWM valve fitted where stepper motor unit goes. With MegaSquirt, I had to add a suitable high current driver
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Re: stepper motor - alternatives

Posted: Mon Sep 09, 2019 5:27 pm
by ChrisJC
I would say that if the stepper works properly, there's nothing to be gained by changing it.

Chris.

Re: stepper motor - alternatives

Posted: Mon Sep 09, 2019 5:35 pm
by stevieturbo
a lot will be down to what your VEMS is happy with using.

A stepper motor would usually be pretty good.

Simple 2 wire valve...simple.

DBW....most versatile.

I would be trying to get a good stable hot idle first, before letting any type of idle control doing anything though, so as to need it to do very little work at all.

Re: stepper motor - alternatives

Posted: Mon Sep 09, 2019 6:43 pm
by DaveEFI
ChrisJC wrote:
Mon Sep 09, 2019 5:27 pm
I would say that if the stepper works properly, there's nothing to be gained by changing it.

Chris.
The hotwire type don't have a good reputation for reliability, I was told. Hence my going for the Bosch. MegaSquirt has a built in stepper motor driver, so that choice was more work. It also seems to be the standard on modern vehicles.

Re: stepper motor - alternatives

Posted: Tue Sep 10, 2019 6:41 pm
by Coops
we ditched the stepper 2yrs ago, and set idle with the butterfly stop for now,
currently have no fast idle control either until Ive finished doing my 2 wire extra air valve set up.

Re: stepper motor - alternatives

Posted: Tue Sep 10, 2019 10:56 pm
by stevieturbo
In a lot of cars, simply using timing for idle control will be quite fine.

Re: stepper motor - alternatives

Posted: Wed Sep 11, 2019 8:47 pm
by SimpleSimon
Bosch 2 or 3 wire get my vote older Volvo Saab BMW GM etc , if you run a big cam ign scatter spark dialing in lots of advance etc wont be enough for warm up so some kind of ICV is essential in some instances, I agree with Dave the Hotwire stepper is a pain in the arse and often erratic in its action Lucas and Megasquirt control

Re: stepper motor - alternatives

Posted: Thu Sep 12, 2019 8:52 am
by DaveEFI
On my SD1 heat soak can be a real problem on a hot re-start. The PWM ICV is set to open further during a hot start, and return to the correct idle speed in a controlled way. Of course you can do this manually using the throttle pedal.