yes. all you gotta do is share the AIT signal with the ecu. basically take your GM sensor, and wire it into the harness itself. the end. you'll have to reflash for the easy therm values, but it's all is needed.

 

OK so instead of running it direct to the ecu as I have it now I just jumper it into the AFM plug as shown earlier. This will not throw a CEL either?

 

yep. the oem ecu sees the signal, since it's through the harness, and likes it. the MS gets the same signal if you built the harness correctly.

 

A quick confirmation that it works with sharing AIT signal. No CEL. Thanks again.

 

I finally was able to purchase a MS kit for Xmas and just finished building it. I've read every piece of information I can find, but I still have some questions.
I have a 1991 NA FYI.

In the DIYautotune article it talks about IAC for the 90-93. It seems I need to replace Q4 with a TIP120 and somehow wire up IAC to the DB37, however nothing is mentioned about this in this guide. Could someone clarify IAC on 91 NAs.

Thanks Guys

 

This guide assumes a "parallel" install in which the stock ECU is left in place to handle, among other things, idle. You will find other differences between this guide and a standalone build as well, such as the biasing of the CLT input line. It's important to be clear about whether you intend to do a parallel or a standalone configuration.

For a standalone install, assuming a Rev 3.0 PC board, all you need to do it hack the TIP120 into the space normally occupied by Q4, do not install Q20 or D8, and jumper across R39. No modifications are required to the DB37 wiring- that's only for people using stepper-motor idle valves, which we are not. (Although you will most likely be using one or more of the four DB37 pins marked "IACx" for other purposes later on)

Consult the purple section under Step 62 of the official assembly guide: http://www.megamanual.com/ms2/V3assemble.htm

Read Step 62 in its entirety before proceeding.

Here's a picture of how mine went together. Since I did not build the injector current limiting circuit, I used the position normally occupied by R37
for the TIP120. You don't have to use this exact position on the heatsink, but it does need to be heatsunk. The tab and body of the TIP120 should be electrically insulated from the heatsink.

 

follow the directions on the mod kit page.

install the tip120 (in place of q16)

remove d8, r39, q2 and q20.

jump r39

install the three leads to tip120. (buy it at radio shack)


on the harness, the green wire will go to 2W. From there install a diode between 2W and 12v. You'll have two extras from D1 and D2 you didnt use.

 

Q2? The fuel pump driver?

 

I'm going boomslang, so I guess I don't need to worry about it. Should have this baby on the car this weekend or next, can't wait to get it working.

 

q4. whatever. said that off my head.

 

A word of advice that I think should be added to the original post.
The settings added to the beginning of the INI file have to also be copied to the section titled lower in the INI called "#else ; Actually only good for DualTable and MSnS-Extra." or else autotune wont work.

You can thank Cjernigan for bringing this to my attention.

 

anyone ever extracted the pins from the gray tyco connectors? i'm slowly assembling my harness, but i'd like to be able to pull out a pin if (when) i screw up. i've tried slipping in a small flathead or scribe, but not luck. any advice?

 

You have the right idea, you have to push in with a screwdriver, and tilt up. There's a tab that falls down behind part of the pin. I used a good solid needle (like a sewing needle or dental tool) since most screwdrivers are too thick

 

is this from the wire side, or from the connector side? there's very little room from the wire side, but it looks like there's the best chance of lifting that tab.

i wasn't sure if there was a lip on the front of that tab that could be easily reached from the front (connector) side.

thanks!

 

tab side, just push the bitch out. you try to angle it as you do so, or else you'll ruin the clip that holds it in. once they go in the are designed not to come back out.

 

with some effort and only minor damage to unrelated components, household pets, and small children, i was able to get the a pin out.

as I'm so ---- and phasing in the MS slowly, i'm building a straight-through harness first to prove that the boomslang is not a problem. After this, I'll start pulling pins and redirecting them to the MS.

Why is it called "overengineering" when someone just does the job "right" the first time?

 

The pins come out really easy when done right. I use a paperclip, strong one, cut the end off a tiny bit at a angle to make it pointed, then stick it in and pry the retaining clip down from the metal crimp in while pulling the wire out. Works great. Took me 30 minutes to get it right the first time.

 

Man, I wish I hadn't tried to phase it in. Almost everything I did that backfired, wasted time, or caused me pain was trying to phase it in. Nothing like trusting in your own abilities.

Since my pic isn't ready yet, try this:

 

Slightly more relavent version.

 

Perfect representation.