# mk3 ABA into mk1 swap, help with vss, stand alone, bogging



## GTIsilverstone (Feb 10, 2004)

Whats up.... I've got a mk1 with a mk3 aba swap already completed. Everything is good but I'm having some problems with the vehincle speed sense... due to lack thereof i'm hitting the rev. limiter in 4th and 5th gears.... I've heard of getting clusters from cabby's and using the appropriate sensor to send the vss to the ECU which fixes the problem.
Thats the first problem. The first question is this.... can somebody school a noob about standalone engine management.... megasquirt kit or something.... Does it replace the ECU or just some component thereof..... if I did standalone would this possibly solve my VSS problem?
The second problem is this: I can drive all day long and have no problems... once I get in stop and go traffic the vehicle starts to bog. I have checked all my components.... fuel pump is newish and good, water pump is newish and good, radiator and fans are all good. Now for the interesting part. My coolant temp gage hovers just under red line but when I use a fancy tempurature reader gun under the hood the temp never gets warmer than standard temp (170 at the highest that I could read). So here's the deal... I'm thinking either my gage is bad or the coolant temp sensor is bad or something in line with that system. So the question lies here.... I've hooked it up so I can cut off the ECU and Cut it back on. When I "reset" it the bogging problem goes away for a while.... which makes me think the vehicle is essentially creating the bogging problem.... is it possible that the vehicle thinks it is overheating and tries to protect itself by bogging a little? any thoughs here would be great!


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## Prof315 (Jan 5, 2009)

*Re: mk3 ABA into mk1 swap, help with vss, stand alone, bogging (GTIsilverstone)*

A megasquirt ( or other standalone) entirely replaces the ECU hence the word standalone. Yes megasquirt would solve the infamous mk3 VSS issue. IMHO there is no better bang for the buck especially on an ABA swap than MS. The factory ECU even chipped leaves a lot of power still untapped and if you decide to modify the motor (cam,SRI, turbo etc..) a standalone really shines. Just retune and you are in business.


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## GTIsilverstone (Feb 10, 2004)

*Re: mk3 ABA into mk1 swap, help with vss, stand alone, bogging (Prof315)*

Thats awesome.... do you have any more experience with the kits? what should I buy... who should install it for me... it already has tt cam and tt chip but i'm thinking about doing SRI and maybe a turbo at some point.... can u point me in the right direction?


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## Vanagon Nut (Oct 19, 2007)

*Re: mk3 ABA into mk1 swap, help with vss, stand alone, bogging (GTIsilverstone)*

Given the bogging issues, are you certain the lack of a VSS is causing rev limiting issues?
On my ABA OBD1, I have no issues running it w/o VSS (in a Vanagon) 
But.... if yours is OBD2, pretty sure it needs VSS signal.
There are "dummy" VSS units that plug in. Can't recall vendor right now, but that may help your search if cluster doesn't work out.
A3 Bentley P. 24a-15 sez that if there's a break in signal between ECT sensor and ECM, "ECU will simulate a fixed signal based on an engine temperature of 176 F"
Testing the ECT sensor isn't tough. It explains how in Bentley.

Neil.


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## need_a_VR6 (May 19, 1999)

*Re: mk3 ABA into mk1 swap, help with vss, stand alone, bogging (Vanagon Nut)*

The lack of VSS is definitely causing the 4th/5th gear limiter but I don't think it has anything to do with the bogging. To solve the VSS issue you need a cluster from a car that had cruise control. 
As far as Megasquirt there are quite a few reputable vendors out there, check out: http://www.megamanual.com/v22manual/mintro.htm the vendor list is there. MS can completely eliminate the stock ecu as well as any issues that it may cause due to lack of VSS, MAF, etc.


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## bansheelos (Nov 29, 2004)

:thumbup:


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