ISCV diode

Specifications, applications, part numbers, and prices for various OEM fuel injection components.

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john.p.clegg
Running MSx/Extra
Posts: 558
Joined: Sat Jul 21, 2007 6:49 am
Location: Manchester

ISCV diode

Post by john.p.clegg »

Dear All
The history..

2008,Ripped all the components of a Ford Mondeo and re-planted them on a 1968 Lotus Elan Plus2 twincam , boy was that a steep learning curve, but successful , running Ms1

Update
2018 Have now sold on the Lotus ( with Dellortos re-fitted) and am in the process of ripping the donor parts off a 2.0 Ford Focus Zetec and transplanting the engine in a 1958 Morris Minor, running Ms1.

The question

The ISCV valve from the mondeo had a diode within its body ( and if one powered it the wrong way would destroy it ), I believe to prevent eddy currents etc ( it's been years since I did emf's etc. ) , but the donor Focus ISCV does not have this inbuilt ( as far as I can test ) and I can see no sign of it in the Ford Focus wiring diagram.

Have Ford altered the way they worked the ISCV ?
Is the diode still needed ?

So , should I fit a diode across the ISCV ? and where should I fit it ? Bearing in mind there is one 12V power lead from the Ms Relay board through the loom feeding both the ISCV and Injectors.

The options
Place it on the relay board 12v power feed to the Injectors and ISCV ?
How if at all would it affect the Injector operation?
Place it directly across the ISCV ?

Please help.
Thanks
John
john.p.clegg
Running MSx/Extra
Posts: 558
Joined: Sat Jul 21, 2007 6:49 am
Location: Manchester

Re: ISCV diode

Post by john.p.clegg »

Just found this which I suppose answers the question

"Put a 1N4001 diode across the PWM Idle valve itself - the banded end goes to the 12 Volt supply, the non-banded end goes to the lead that goes to your MegaSquirt® controller (this diode is for flyback purposes on the idle valve)."

John
jsmcortina
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Re: ISCV diode

Post by jsmcortina »

Yes you need the diode.

Do consider upgrading to at least MS2. While it can still work, MS1 is pretty old and clunky now.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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john.p.clegg
Running MSx/Extra
Posts: 558
Joined: Sat Jul 21, 2007 6:49 am
Location: Manchester

Re: ISCV diode

Post by john.p.clegg »

James
So am I,so is the Morris Minor....you will be too .....one day.

Thanks
John

P.S. I remember what a steep learning curve it was in 2008...and I'm not getting any younger.
kjones6039
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Location: Eureka, NV USA
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Re: ISCV diode

Post by kjones6039 »

Hahaha........ You young guys are too funny!

Ken :lol:
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/extra 3.4.2 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
TinyIOX from JBPerformance
LAV1000
Super MS/Extra'er
Posts: 1489
Joined: Sat Dec 17, 2011 10:18 am
Location: Netherlands

Re: ISCV diode

Post by LAV1000 »

john.p.clegg wrote:James
So am I,so is the Morris Minor....you will be too .....one day.

Thanks
John

P.S. I remember what a steep learning curve it was in 2008...and I'm not getting any younger.
So you did master the MS1, you do understand the EFI principals.
Why not stepping up to MS2 ?
Youre mind is a free tool and exercise doesn't make you any dumber, maybe a headache. :D
And there is stil a great forum to support you.
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