T3Bunny, 1977 VW Rabbit, Turbo ABA

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T3Bunny
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T3Bunny, 1977 VW Rabbit, Turbo ABA

Post by T3Bunny » Sun Aug 02, 2015 10:13 pm

Over the years I have built and or assisted with building and MegaSquirting a LOT of Volkswagens (and many other marque too). In fact for many years, I did this and built harnesses and ECUs as my main job!

I have owned enough myself, I can't easily count them. But when I water it down to the ones that are really memorable, the number gets smaller. When I count just the ones I 'squirted and drove for more than a few years, there are just two. This one is my favorite. For many years, it was my dream car to own!

Vehicle: 1977 Volkswagen Rabbit L (2dr)

Engine: 2.0L 8Valve ABA (I4) T3To4e turbocharger, stock 10 to 1 compression, Autotech Sport Tuning turbo cam, adjustable timing sprocket, windage tray + pump pickup baffles (both VW)

MegaSquirt: MS3 in a V3.0 ECU. I tend to update code every 6 months or so, usually to an Alpha or Beta release.

Injection: Multi-port injection, (forget injector size...), Stock ABA fuel rail, 3.0bar fuel pressure regulator, OBD1 Throttle body, GM coolant and air temp sensors

Injection is wired and setup for full sequential, but has been run in Semi-Sequential most of the time. Oddly, it seems to run smoother on Semi... Currently, a bad distributer plug keeps me from bothering. Another project, I need to go Full and get my MPG back!!!

Ignition: I am setup to run the stock ABA internal VR crank sensor, and using the Hall sensor in the distributer for a Cam reset signal. These go in through the V3.0 Maniboard utilizing both VR and Optical circuits!

Description: Well this car started out its life with me 6+ years ago, on a V2.2 running MS1 and MsnSe code. Eventually, I got bored and wanted a change. The swapover to MS3 was not without some issues though...

I had the car fired and running on MS3 on the first start attempt. But somehow in the process of checking ignition timing, a setting got whacked. I was using LED spark output as a carryover from the MS1 setup. Somehow it got changed to injection, and it went unnoticed for a while. Car still ran, surprisingly. But not well. And in the process of trying to find the issue, I cherried my old turbo. Still have a bad burn scar from that. The turbo was done. And a year or so later, the original engine gave up the ghost from damage sustained by the turbo bearing failure.

The wiring is, interesting. Hazard of having built harnesses for many years, mine is WAY over complicated. First I tore out the 1977 harness and grafted in a 1983 "Westmoreland" harness and fusebox. Then I scavenged and reconfigured relays and wired the MegaSquirt into the OE fusebox.

Eventually, I upgraded this and isolated most of the MegaSquirt and related engine controls into its own dedicated aviation breakers (installed in the glovebox). Currently, the fuel pump power is the only thing still ran through the OE fuseblock. Likely due to lack of a correctly sized breakers on hand... Someday, I will have to address this final problem area. Bad contacts here have caused me no start issues a couple times.

I have several rows of terminal blocks mounted underneath the passenger side raintay/dash for all my I/O. I WISH I had taken a similar approach as I did with my Turbo Cabriolet.... I had a drop down underdash panel that allowed me much easier access to the wiring. Unfortunately, rearranging the wiring enough to drop it down, will be a SERIOUS nightmare! But if I finally do decide to put AC into my car, I may have no choice... It is NOT user friendly to work on as it is.
Forget the porn, my bathroom is full of car manuals...
1977 Rabbit
1991 Cabriolet (retired)

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