Author Topic: Digifant Throttle Body  (Read 690 times)

Offline MatthewB

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Digifant Throttle Body
« on: 19 November 2018, 12:23 »
https://imgur.com/a/rVE3Iy4Hi, I'm new to this forum as I have recentley bought a 1.8 8 valve GTI with Digifant injection.  I'm now looking for some advice as I am a little confused. I’ve just removed the throttle body to clean and inspect it (I am having issues with fluctuating revs) and I noticed hat there are two pipes (one each side of the body, see photo) that have been blocked off with ball bearings.  Is this correct, if not where should they connect to?  I’ve searched in this  forum for any information on where the various pipes should go to from the Throttle Body but can’t seem to find any answers!  Apart from the fluctuating revs the car is running well so I don't think these are a problem but advice/suggestions would be welcome. Thanks in anticipation. (Hope I've inserted this image correctly!!!)
« Last Edit: 19 November 2018, 12:26 by MatthewB »

Offline gazareth

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Re: Digifant Throttle Body
« Reply #1 on: 20 November 2018, 14:45 »
sorry. cant see the pic?

Offline gazareth

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Re: Digifant Throttle Body
« Reply #2 on: 20 November 2018, 14:46 »
it's probably a dirty idle valve though.

Offline MatthewB

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Re: Digifant Throttle Body
« Reply #3 on: 20 November 2018, 16:13 »
Hi, can you see the photo if you click on the hyperlink at the beginning of the post?  If not I can email the image to you or alternatively you could advise how I post a picture if this is not the correct way. Thanks for responding, I'll look at the idle valve.

Offline MatthewB

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Re: Digifant Throttle Body
« Reply #4 on: 22 November 2018, 16:33 »
Hi Gazareth, cleaned the idle valve but this only exacerbated the problem (before it only reved up and down a couple of times before it reached a steady state), when I now raise the revs and then drop them off the car revs up (faster than before I cleaned it) then revs down, revs up again (but not as much) then revs down again( but a little faster) this keeps on going on (a bit like a pendulum slowly settling) until constant steady revs are achieved.  As cleaning the valve seems to have made the situation worse I’m going to try and replace this valve with a new one to see if this works.  Has anyone any thoughts on why (if the idle valve is not at fault) this should happen?  As a matter of interest I now think the two blocked off pipes where for the American market for a carbon filter so should not be related to this problem.
« Last Edit: 22 November 2018, 17:49 by MatthewB »

Offline gazareth

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Re: Digifant Throttle Body
« Reply #5 on: 23 November 2018, 02:48 »
to be honest, it's been a while since iv'e had any bother like this :whistle: if you warm the engine up, then wind the idle screw out a few turns, then crimp the hose from the intake boot to the idle valve. if that clears the problem, then the valve must be the culprit :wink:

Offline MatthewB

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Re: Digifant Throttle Body
« Reply #6 on: 24 November 2018, 16:35 »
Hi, changed the idle valve for a new one, seemed to have made a difference, however, on revving and then taking foot of off the accelerator the revs drop down low and then immediatley climb back up and stabilised to around 800 RPM.  Is this normal Digi behaviour?

Offline gazareth

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Re: Digifant Throttle Body
« Reply #7 on: 30 November 2018, 15:00 »
you might have to adjust the idle screw.

Offline Pete_VW

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Re: Digifant Throttle Body
« Reply #8 on: 24 December 2018, 00:49 »
Hi, read RubJonny's tuning guide in the stickys, great info there. Work thru that systematically and it may well resolve your issue. Disconnect your ICV, and if the engine doesnt stall, you might have an idle switch problem. The bouncing revs at idle in my case was bad earth between ecu and idle microswitch. (Wiring corroded @ plug). Grab your multimeter and test continuity between idle switch (brown & white) & ecu terminal 6. Hope this helps. Cheers.
Current: 1991 5dr 8v Gti. Ported and polished PB head, fast road cam, mk3 AGG 2.0l block, 16v box, corrado g60 clutch, full stainless, big bumper, loads of other stuff I've forgotten about.

Previous VW: mk3 Golf 2.8 VR6 skyline