Long, slow Megasquirt conversion, Sad D-Jet times Options

[r3dplanet]

Kameraden -

I own a lovely, though far from perfect, 1971 914 with a stock D-jet fuel injection system. I bought the car almost a year ago, and during that year I've tried hard to make the thing run correctly. It's never happened. After spending apparently a thousand hours reading and re-reading the available D-Jet literature and forum posts and testing and replacing every D-Jet part I can think of, I've decided that the best way to proceed is to purge by fire.

My goal is simple: all I want to do is to make my car run as smooth as it is capable of running. I'm not after performance gains, but I also don't want to suffer any losses. I don't drive my 1.7 liter car to go fast, I drive the car because I love what it is: small, efficient, fun. If I need a speed fix I can just as easily hop on my motorcycle or jump into my hopped-up Barracuda.

If this process helps me think out loud and use the available wisdom here, then surely it will help others on what I'm expecting will be an increasingly common path. I dig the D-jet injection system, but the fact is that parts are becoming more rare, more expensive, and more uncertain. Another major factor for my action is that there are too many unknowns when trying to diagnose the D-jet. Just when I think I have it nailed down, the air temperature drops ten degrees and the car barely runs, which makes for a crestfallen, tongue-gnashing experience. With the Megasquirt setup, I can hook up my Thinkpad and just find out what's happening with the injection system. To me, this alone is worth the price of admission.

The unit I've chosen will either be a Megasquirt II v.3 unit or a system based on it. After reading the comparisons between the systems it seems that the MS II v.3 is newer enough for all I want to do, and also because the MS III system simply is too complicated for my needs. What are my needs? Right now I want to do a fuel-only setup, but perhaps later I'll install an optical crank sensor and go for spark/timing control.

Let's begin.

From eBay and diyautotune.com I have ordered and received a Bosch oxygen sensor, Innovate controller, dash gauge, and MS stim kit. Since my Bursch exhaust already burned off all the paint from its year-old rattle-can paint job from the previous owner, I decided to begin with the oxygen sensor install. This would be a handy thing to have even if I kept the D-jet system just for the sake of curiosity. Am I running lean or rich? Who knows? Well, the O2 sensor knows. So this morning I detached the exhaust and had a local exhaust shop weld in a sensor bung. I then began to lace the wires along with some existing turn signal wiring. I'll have pictures of this shortly.

After the bung was welded in, I made a $10 soda blaster like the one you can see here:

http://www.aircooledtech.com/tools-on-the-...p/soda_blaster/

I blasted the exhaust using four small boxes of baking soda obtained from the drug store down the street. I then shot it with a little hydrochloric acid to eat any remaining schmutz and rust, and then I hosed it clean with water to neutralize. Normally I like to send off my exhaust projects to be Jet-Hot coated, and I'm a believer in the process. The exhaust manifolds on my Barracuda and the headers on my Falcon were both Jet-Hot coated and they look brand new many years later. Its expensive but worth it. I didn't Jet-Hot the Bursch only because my neighbor gave me a can of Por15 Black Velvet exhaust paint. It's a brush-on affair where you paint on a coating the consistency of dairy "pudding," let it dry, brush on another coat, and then let the heat of the running motor bake it into place. I'm dubious, but it was free and I have nothing to lose by trying. It can't be any worse than the thoughtless Krylon job it was sporting until this morning. We took some photos of the process and I'll post them later.

Next up is wiring up the dash gauge and soldering the stim kit together.

Thanks for reading.