Porsche 914 Megasquirt owners!

bowlsby · Post by **bowlsby** » Wed Apr 17, 2002 2:58 pm

914 Megasquirt owners, I am interested in your feedback.

I've briefly studied the Megasquirt ECU wiring schematic, with the hope that existing servicable D-Jet 914 FI harnesses could be modified to adapt to the new ECU, or to simply design/build a new MS version 914 FI harness. At first glance it seems that a new harness is easier and better. The mods required to adapt an existing harness may not be worth the trouble and reliability is questionable. New harnesses are not a problem for me 8^)

I am working on the premise that many or all of the same or similar engine mounted FI components could be used with the MS ECU. The MS schematic shows many of the same generic FI components, but the MS ECU seems to switch grounds rather than switch source voltage for control as in OEM D-Jet, so they are wired quite differently.

I need wiring information from the Megasquirt paperwork indicating recommended wire gauges to each of the components, to confirm if the existing wires are compatible and to reuse certain abandoned wires for new uses.

A few of the specific portability issues:

1. Add a wire for an O2 sensor (reuse 1 trigger switch wire)
2. Add a wire for the coil negative signal (reuse 1 trigger switch wire)
3. Reconfigure the TPS wires to a new TPS (I think) abandon 1 TPS wire
4. Relocate 1 of 2 existing TS1 wires to ground
5. Add 2 new wires for fast idle solenoid
6. Abandon all 4 fuel injector ground wires, and add 4 new wires, 1 for each injector
7. Abandon/reuse 4 MPS wires

I may be willing to work with MS ECU convertees as needed to develop a 914 specific harnesses. Remember there are originally 6 D-jet and 2 L-Jet 914 engines, for as many as 8 different harness configurations to potentially develop. Those could possibly be reduced to only 2 D-Jet and 1 L-Jet harnesses.

Contact me offline if you are interested.

Jeff Bowlsby
[email protected]

PapaG · Post by **PapaG** » Wed Apr 17, 2002 3:33 pm

I think brad anders is looking at MS. I am going to put it on a Type3 (69) fastyback that a po took off the efi. You may want to post on the MS yahoo list too. Several others on the MS list were going to use them on aircooled engines, but I don't know if they hang out here too.

------------------
Richard
Lost in Texas
68 Chopped Top Squareback (wasserboxer conversion)
69 Fastback Auto (MegaSquirt EFI)

bowlsby · Post by **bowlsby** » Wed Apr 17, 2002 8:57 pm

Thanks PapaG. there is a discussion going on about the idea over on the www.pelicanparts.com 914 tech forum.

I have a couple T3 FI harnesses, I could figure something out for them too.

PapaG · Post by **PapaG** » Thu Apr 18, 2002 11:33 am

Jeff:
Ben Willis posted this to the MS list. Here is the link to a 911 running MS go to the end of the topic to see the pictures
http://www.pelicanparts.com/cgi-bin/vb/ ... adid=10077

[This message has been edited by PapaG (edited 04-18-2002).]

bowlsby · Post by **bowlsby** » Thu Apr 18, 2002 11:53 pm

Thanks for the link PapaG, thats a great discussion. It looks like only the connector portions of the original harness were used, the bulk of the harness was rigged. Good for a mock-up prototype, but there are better long term solutions.

I would be concerned about mounting the ECU in the engine bay solely from a weather exposure standpoint. I simply would not do it. The case and the computer style connectors allow water intrusion. Not a comfortable feeling.

The MS ECU seems to be designed well from an electrical engineering standpoint, it accomplishes its design goals, but something should be done to make it durable in an open engine bay environment or simply locate the unit in a protected location.

PapaG · Post by **PapaG** » Fri Apr 19, 2002 8:43 am

I aggree on the location. I guess you could seal it using some gaskets or silicone (correct type only

) I was going to mount mine in the passenger compartment, under the rear seat, or in the trunk of my fastback. I think someone brought up using the factory ECU case in that post. I bought a whole Type 3 ecu and wiring harness off ebay for $10.00 so when I get it I am going to look and see if that is possible.
I'll let you know and post some pics. I havent started building mine yet. I was going to build a engine test stand and get it running there first, but I dont know now.

------------------
Richard
Lost in Texas
68 Chopped Top Squareback (wasserboxer conversion)
69 Fastback Auto (MegaSquirt EFI)