VX lean burn monitor - enhanced how to desired

[monroe74]

"but quite complicated for an electrical novice like myself"

I'm getting helpful info from a simple DMM. At Harbor Freight they start at $4. That would be enough to monitor mixture (lean burn). I paid more ($33) for a meter with a dwell-angle feature. That lets me monitor how long my injectors are open, which is a direct measure of true, instantaneous fuel consumption.

It's not hard to do. I'd be glad to explain how to do it.

[jadziasman]

I just looked at the 96 - 98 Civic Helm shop manual. It seems that instead of a test harness to connect to the ECU, back probe pin adapters are used on a standard DMM to connect to the pin outs on the ECU.

Has anyone tried this? It looks like it would work to access D14 and D16.

[monroe74]

"Has anyone tried this?"

I think some kind of back probe would work fine. Like this:

http://www.backprobe.com/
http://www.smartchargers.com/products/22

Or this:

http://www.amazon.com/Automotive-Bac.../dp/B000I16DKM

But I wanted something cheaper, that I could find locally. Radio Shack had the perfect thing:

http://www.radioshack.com/sm-quick-s...i-2998435.html

Too bad there's no picture. These are called Quick Splice Connectors or T-Tap Connectors. Some more:

http://www.mouser.com/search/Product...538-19216-0018

http://www.vanco-online.com/index.ph...ucts_id=101458

http://www.magnadyne.com/index.cfm?M...&Web_CatID=193

Each approach has its own advantages. The RS product worked great for me, for this exact purpose (tapping wires near the ECU).

I tapped D14 and D16, to monitor AFR. I also tapped A1, to monitor the injectors (this requires a DMM with dwell, but I found one for only $33). This is very helpful, because it gives me a precise indication of instantaneous fuel use.

I also tapped D18, because my car has no SIL (shift indicator light), and I was curious what it would be like to have one.

There are some other interesting things to tap, but so far I haven't bothered.

I've also become very interested in the possibility of using a cheap ($25-50) data-acquisition interface to display/capture all this data on a laptop, instead of a DMM. I think that creates all sorts of interesting possibilities, greatly exceeding what a Scangauge can do. I wonder if anyone here has any thoughts about this idea.