ahh crud MPS is gone

[hardflex]

My car started running a little rough, and I noticed it seemed to be using a lot of gas. So when I stopped for gas, pulled the vacuum line off the manifold, and sucked on it to test it, it didn't hold...

I'll probably park it today until I find a suitable solution.

[Dave at Pelican Parts]

Sorry to hear that...

When mine eventually goes, I'll probably make the jump to Megasquirt.

--DD

[hardflex]

I have been pondering the same thing. Did anyone come out with the ready made wiring harness for that?

[Dave at Pelican Parts]

Not that I know of... You might ping Jeff Bowlsby, or look through his site at http://members.rennlist.com/914_wiring_harnesses .

--DD

[pbanders]

Just thinking about a MS-based D-Jet replacement solution.....

Imagine a system where you remove the MPS, and in the same position, you put a solid-state pressure sensor that plugs into the D-Jet harness. That's the only sensor you replace. You now plug the D-Jet harness into a "black box". On the other side of this box, you plug in the MS ECU.

Inside the black box, the trigger contact points output is converted into an appropriate signal for the MS engine speed/position sensing. All sensors are routed, and power is supplied. Any other massaging required is also done.

Hmm, such a product would make it pretty simple to replace virtually any D-Jet system with modern components...

edited - I forgot, now you MS people out there tell me why this won't work....

[hardflex]

think on it some more, I'll be your first test monkey

[pbanders]

Fact is, I need to look at the MS stuff, and talk to people who have done the conversion. My goal would be to do a MS conversion with the least deviation from stock appearance and components. I suspect it will require a new throttle position sensor, too.

[Dave at Pelican Parts]

MS uses a potentiometer-based TPS. Almost all of the ones that are readily available turn the wrong way for use on the 914, sad to say.

You can probably re-code the MS to use the "pulses" from the stock type TPS, though those are now hard to find as well...

I had given some thought to running the hose to the MS MAP sensor inside the new EFI wiring harness that I would build for the MS ECU. The MAP sensor is usually soldered onto the circuit board, ya see. And I further thought about putting the ECU inside a case for a D-jet one. That seems significantly easier than trying to put "something" inside a gutted MPS.

--DD

[pbanders]

So, the pot would have to turn CCW? That should be interesting to find! Why not use a plastic gear to solve this problem?

I'd forgotten they have the MAP on the PCB. It'd be simpler to do what you say, and not use the harness connector for the MPS. And mounting the thing in a ECU case sounds good, too.

Now, all I need is time to work on this - that ain't happening soon.... I'm sure someone else out there will do this first. Hope it's someone like Jeff who can commercialize it so I can simply buy it!

[bowlsby]

Well the wheels have bee turning for sometime actually. Jeff Keyzer, another 914-owner EE and I have developed the schematics for an aftermarket EFI harness that would be plug and play for our 2.0L cars and applicable to MS and other aftermarket systems. Turns out the boys figure that the new systems are much more sensitive to EMI conditions so additional grounding and routing considerations are implemented. The wiring schematic and harness configuration for aftermarket FI is significantly different than D-Jet too.

In addition to MS, be sure to look into the other aftermarket FI systems, there are some good solutions available. All will need some type of wiring harness for the 914 engine and many need replacement FI components. Adapting and reusing a 35 year old D-Jet harness is not practical or even feasible.

I am in the process of moving my household over the next few months, but once settled in, this new harness will begin fabrication. I have had a few requests for these already.

[James M]

My MS breakout box inside a d-jet brain. pretty much plug and play megasquirt and it keeps everythign looking stock.

I didnt want to trash that fancy/expensive RES wiring harness i bought years ago.

[Dave at Pelican Parts]

I am told that Dave Hunt has an MS board put together inside a stock ECU box, with a wiring harness to match. He has bolted a modern potentiometer-based TPS onto the stock TPS circuit board and got the cover to fit it (must be a "backwards" TPS). Not sure if the MAP sensor is in a gutted MPS or not.

Sounds pretty effin' sweet, though! I hear that one will be a door prize or a raffle prize at the West Coast Ramble...

--DD

[James M]

I have a similar setup for my TPS, modern Bosch unit on the stock TPS board wired into the stock TPS connector. Ill see if i can get the part number off the TPS when i get home.

[captjm]

What are the numbers on your broken MPS?
I have two spares that might work for you-

[hardflex]

i'll check tomorrow. it's a 76 2.0 liter motor, if that is any indication.

[captjm]

The two I have are
0280100019 and
0280100041
I am not sure what year 914's they came from.

[hardflex]

Those part no's don't come from 914's. If they are good, I might be able to have them calibrated to work. Have you checked them?
Does Bleyseng still do that?

[captjm]

both of these came off of two 914's headed for the junk yard. They both will hold vacum pressure.

[hardflex]

I put one on from a 1. 7 that I have that was adjustable. Seems to be lots better than it was.

I haven't given up on your stuff, I have others I need to keep running.