# MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (????)



## gebamut (Jul 26, 2007)

Hello i have just completed a 1.8t MK2 swap, and ran into a problem. I have spliced and connected the AEB passat/audi wiring with the CE2 Mk2 wiring, the cluster works (lights come on, and gasoline gauge works). The speed will also work i believe, since it runs on speedo cable, but my question is how do i get the RPM on my MK2 cluster to work ? 
I f anyone knows please let me know. I need to get this project complete; its been taking too long.


----------



## vr6swap (Aug 17, 2001)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (gebamut)*

Seems that I've been proven wrong, so stay tuned for futher updates. http://****************.com/smile/emgift.gif 


_Modified by vr6swap at 10:44 AM 3-10-2008_


----------



## Veedubgti (Mar 5, 2001)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (vr6swap)*


_Quote, originally posted by *vr6swap* »_Internet car builders will tell you to use the MSD converter box that sells for about 60 bucks at Summit, but we tried one of those last year and they don't seem to work on 1.8T swaps. If anybody thinks otherwise, post up how you wired / configured the box to make it work. 

Yo Glenn.
I really don't consider myself an internet car builder, but I can assure you that a MSD 8920 tach adapter 100% absolutely works with a Mk2 cluster and AEB engine. I've done 3 of them, including one on my own and they all work as advertised. In fact, mine has been in my car since 2002. You have my word








A simple 4 wire hook up. Key-on, ground, tach signal from AEB ECU to converter box, converter box to tach wire on cluster. I can get you the pin numbers off of my diagrams when I get home. 










_Modified by Veedubgti at 9:13 AM 3-10-2008_


----------



## vr6swap (Aug 17, 2001)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (Veedubgti)*


_Quote, originally posted by *Veedubgti* »_
Yo Glenn.
I really don't consider myself an internet car builder, but I can assure you that a MSD 8920 tach adapter 100% absolutely works with a Mk2 cluster and AEB engine. I've done 3 of them, including one on my own and they all work as advertised. In fact, mine has been in my car since 2002. You have my word








A simple 4 wire hook up. Key-on, ground, tach signal from AEB ECU to converter box, converter box to tach wire on cluster. I can get you the pin numbers off of my diagrams when I get home. 









_Modified by Veedubgti at 9:13 AM 3-10-2008_

Have I been pwnt? Could be.







Maybe the box we had was defective, or maybe it works with AEB coils and not the later DBW management, you think? 
If you could post how you wired it that would be huge help to a lot of people, including us. As best I can tell, a $59 MSD converter box is probably cheaper than a $299 tach converter box from MMP.


----------



## Veedubgti (Mar 5, 2001)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (vr6swap)*

I haven't tried one on a AWW/AWP so I can not verify. I'll post up the pin #'s tonight.


----------



## Crazy Hungarian (Feb 10, 2002)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (Veedubgti)*

I too have one of these tach adapters on a AEB 1.8t....it works fine on ce1 and ce2 mk2 golf and jetta clusters, works fine on a 16V rocco cluster....but it will not work on a mk1 cluster...rabbit, jetta, cabby, etc.
Don't know the reasoning, all I know is what did and didnt' work when I connected wverything up (I was playing around with clusters on a mk1 jetta 1.8t swap)


----------



## Veedubgti (Mar 5, 2001)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (Crazy Hungarian)*

OK, the MSD 8920 has 4 wires. A red, a black, a violet, and a white.
Red...........Key-on power (no brainer)
Black........Ground source (no brainer)
White.......TACH OUTPUT (T-10 black <10 pin connector in engine harness> pin number 2. The wire _should_ be green w/blue tracer.)
Violet......TACH INPUT (G1 pin number 12 on CE-2 engine harness)
I'm not sure of the pin number for a non-CE2 car, but it's whatever the RPM input wire is from the coil. 
I hope this clears up tach issues for Mk2's with AEB swaps. This is the ONLY combination I personally can verify.










_Modified by Veedubgti at 7:34 PM 3-10-2008_


----------



## Veedubgti (Mar 5, 2001)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (Veedubgti)*

A little bonus information about the wire at T-10 Black, pin number 2......
This wire comes FROM the ECU itself and not a coil. The ECU is what is physically sending the signal to the MSD Tach Adapter.


----------



## vr6swap (Aug 17, 2001)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (Crazy Hungarian)*


_Quote, originally posted by *Crazy Hungarian* »_I too have one of these tach adapters on a AEB 1.8t....it works fine on ce1 and ce2 mk2 golf and jetta clusters, works fine on a 16V rocco cluster....but it will not work on a mk1 cluster...rabbit, jetta, cabby, etc.
Don't know the reasoning, all I know is what did and didnt' work when I connected wverything up (I was playing around with clusters on a mk1 jetta 1.8t swap)

This is where we had the problem. Both 1.8T swaps I've worked on were Mk1's. Jeff is currently doing a Mk2 swap, so we'll see how that shakes out. 

_Quote, originally posted by *Veedubgti* »_OK, the MSD 8920 has 4 wires. A red, a black, a violet, and a white.
Red...........Key-on power (no brainer)
Black........Ground source (no brainer)
White.......TACH OUTPUT (T-10 black <10 pin connector in engine harness> pin number 2. The wire _should_ be green w/blue tracer.)
Violet......TACH INPUT (G1 pin number 12 on CE-2 engine harness)
I'm not sure of the pin number for a non-CE2 car, but it's whatever the RPM input wire is from the coil. 
I hope this clears up tach issues for Mk2's with AEB swaps. This is the ONLY combination I personally can verify.











This info should be posted in the 1.8T swap info thread if it hasn't been already.


----------



## PtownVdub (Jun 22, 2006)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (Veedubgti)*


_Quote, originally posted by *Veedubgti* »_I haven't tried one on a AWW/AWP so I can not verify.

I am using the MSD tach converter (PN 8920) with my AWP swap in my 1987 GTI. The GTI has the pre-CE1 wiring (I have heard it referred to as Golf wiring) and the instrument cluster has two connectors going to it. My tach works great and I verified that it is accurate compared to the reading that I get when I scan the car using the VAG-COM. http://****************.com/smile/emthup.gif


----------



## DubGray1.8T (Sep 24, 2003)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (Veedubgti)*


_Quote, originally posted by *Veedubgti* »_OK, the MSD 8920 has 4 wires. A red, a black, a violet, and a white.
Red...........Key-on power (no brainer)
Black........Ground source (no brainer)
White.......TACH OUTPUT (T-10 black <10 pin connector in engine harness> pin number 2. The wire _should_ be green w/blue tracer.)
Violet......TACH INPUT (G1 pin number 12 on CE-2 engine harness)
I'm not sure of the pin number for a non-CE2 car, but it's whatever the RPM input wire is from the coil. 
I hope this clears up tach issues for Mk2's with AEB swaps. This is the ONLY combination I personally can verify.









_Modified by Veedubgti at 7:34 PM 3-10-2008_
 I can verify this one as well I ran one for around 4-5 years. It did finally die though. Just need a new adapter


----------



## GTOBB (Dec 30, 2003)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (gebamut)*

YOU MUST USE 4 DIODE AND ITS WORKING GOOD !
more info on priv if you want.


----------



## HidRo (Sep 19, 2003)

I went digitial Corrado cluster (digital as in odometer) and I just had to connect the pin 6 to the cluster.


----------



## vwtoby (Sep 8, 2000)

*Re: (HidRo)*

great info guys!
so this works for a corrado cluster running a VR6 too??
thanks


----------



## vwtoby (Sep 8, 2000)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (gebamut)*

can anybody comment on my my buddies comment below after i asked him about this:
"I don't know, you have a different issue, pairing a 6 cylinder signal to a 4 cyl tach. I think you'll at least need to run a tach from a VR6 car unless that MSD converter does that kind of thing.
the early tach's triggered right from the coil, so there is a huge kick back voltage spike which drives the needle. The new cars have a low voltage pulse from the ECU, so there just isn't enough voltage there to drive the old tach. The MSD bok is basically a small relay coil and a couple of diodes, turns the small signal into a high voltage spike. It might make your tach work but I am pretty sure your revs will read very wrong because of the 6 cyl thing. the thing would read a full rev when the motor is only 2/3 around. "


----------



## MikkiJayne (Jan 1, 2007)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (vwtoby)*

This box from Dakota Digital does the same thing as the MSD box, but also allows you to correct the signal for different numbers of cylinders between the engine and tach http://****************.com/smile/emthup.gif 
http://www.dakotadigital.com/i...7.htm


----------



## vwtoby (Sep 8, 2000)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (MikkiJayne)*

cool...is it plug and play?


----------



## engai69 (Sep 9, 2005)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (vwtoby)*

I like that digital dakota one. more for less money. and they have been around for a long time. http://****************.com/smile/emthup.gif


----------



## vwtoby (Sep 8, 2000)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (engai69)*

anybody made the Dakota one work??


----------



## gebamut (Jul 26, 2007)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (vr6swap)*

Hey guys sorry for such a late response... By the way, the MSD converter is an absolute easy 4-wire splice, 100% working, I speak from experience cause I use it on my car for about 4 months now !!! Thanks everyone !







http://****************.com/smile/emthup.gif 


_Modified by gebamut at 5:22 PM 9-28-2009_


----------



## eizo (May 5, 2008)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (gebamut)*

hello guys! i recent buy msd tach adapter and put it to my mk2 agu swap...
it doesnt work!!!!! i am running digifiz cluster.... any ideas???
should i try with the original cluster?


----------



## gebamut (Jul 26, 2007)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (eizo)*

I used my stock cluster with the MSD and connected it just as listed above and it works perfectly for more than a year now.


----------



## donx22 (May 19, 2008)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (eizo)*

may be a late reply sorry. but i jst noticed ure digifiz post, it should work with the sognal striaght form the ecu to ure digifiz!
if uw anted mk4 clocks to work u would take the signal form pin 7 on the box next to the ecu on a digifant car. so it should work the opposite way aorund for digifiz cluster to ecu


----------



## freeflow90 (Apr 19, 2003)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (Veedubgti)*

kinda off topic but can you use this with VR6? Ive heard you need another box to make it from a 4 cylinder to a 6??


----------



## mk2jerm (Jul 18, 2007)

*Re: MK2 20v 1.8t engine/with AEB passat wiring. RPM Problems (freeflow90)*

subscribed!


----------

