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Model specific boards => Golf mk2 => Topic started by: dubstar81 on 18 November 2008, 12:26

Title: Digifant to Kjet
Post by: dubstar81 on 18 November 2008, 12:26
Hi guys
Just converted my mk2 gti from a 1.8 digi to a 2.0 k jet.
Everything is running sweet apart from when i turn the ignition on you can hear the fuel pump priming the fuel lines but it stays on constantly. I'm pretty sure its only meant to buzz for about a second.
Any ideas?  :sad:
Title: Re: Digifant to Kjet
Post by: ToddyGTi on 18 November 2008, 12:30
K-Jet is CIS whereas Digifant is CIS-E.

CIS means continuous injection System meaning the injectors are always open and pumping fuel in.
CIS-E is Continuous Injection System Electronic which is where the injectors pulse open and closed giver better economy and better timing.

I'm presuming that the Fuel pump will always run on a CIS system but I'm sure someone will clarify for me. Cheers.
Title: Re: Digifant to Kjet
Post by: Diamond Hell on 18 November 2008, 13:28
(http://skugg.files.wordpress.com/2007/06/can-of-worms.jpg?w=164&h=280)

Now why would you do that?

A correctly set-up K-jet should prime and stop the pump once primed.
Title: Re: Digifant to Kjet
Post by: dirtydub on 18 November 2008, 14:09
yep i think your right mines a 1.8 8v kjet and it primes for a second then stops
i dont know how to remedy this but im sure one of the guys will be along shortly to tell you
Title: Re: Digifant to Kjet
Post by: rubjonny on 18 November 2008, 14:44
digifant isnt cis-e, cis-e is something entirely different, its k-jet basic with lambda and/or knock senseing strapped on the side.

more info is required here, what kind of 2.0 is it, 8v, 16v? what managment is it exactly, did you also change the main fuel pump & lines etc?

If its basic 8v k-jet the priming is controlled by the pump relay which is different to the 8v digi one.  If its running MK2 KR 16v k-jet then the priming is controlled by the ecu, the digi relay is compatible with it.
Title: Re: Digifant to Kjet
Post by: dubstar81 on 18 November 2008, 18:10
The bottom end is out of a mk3 2.0l 8v Gti.
The top end is is out of my old 86 Kjet gti 1.8 8v and i tranfered most of the wiring loom,fuel pump and ran new fuel lines.
Its totally standard apart from the 2.0l bottom end.
I'm thinking it could be a crossed wire somewhere.
Title: Re: Digifant to Kjet
Post by: Conker on 18 November 2008, 19:57
I'm thinking it could be a crossed wire somewhere.

Fuel issue and crossed wires.  I wouldn't catch a lift in your car !!   :shocked:

Only joking.  Hope you get it sorted.
Title: Re: Digifant to Kjet
Post by: rubjonny on 19 November 2008, 09:13
it would have been much easier to run it on the existing digifant managmnet, but never mind! Your problem is most likely you have the wrong fuel pump relay, the digifant one wont work.  You need to get yourself a pre-87 MK2 k-jet pump relay :)

I take it you have the complete k-jet bay wiring loom fitted right?
Title: Re: Digifant to Kjet
Post by: dubstar81 on 19 November 2008, 15:01
No the wiring loom had been chopped. what i had was the fuse box to engine bay, but say about half a metre of wires from the fuse box back. So they had to be splice and rejoined.
Title: Re: Digifant to Kjet
Post by: dubstar81 on 24 November 2008, 18:25
Any more ideas ladies and gents?
I still have no idea
Title: Re: Digifant to Kjet
Post by: Diamond Hell on 24 November 2008, 19:46
Where are you?
Title: Re: Digifant to Kjet
Post by: dubstar81 on 30 November 2008, 18:14
I'm down in Plymouth.
I have been doing some research and i found out that the digifant runs a higher pressure than the K jet and the K jet has a sort of booster pump within the tank to prime the fuel pump, so what i have found done is found one, And also i managed to come across a complete k jet wiring loom.
The plan is if the pump doesn't sort out the priming problem i am going to rip out the old crappy loom and replace it with a proper one.
Title: Re: Digifant to Kjet
Post by: danny_p on 30 November 2008, 18:19
k jet runs higher pressure than digi,      both systems have 2 pumps,  the intank pump is same for both  the under car pump is diffrent