COOL LOVE MEGASQUIRT thats awesome that have it where you dont have to slice any wires. I have few questions if anyone can answer them.
1. Does it give you your 2 second prime for fuel pump?
2. Is there any under hood wire mods you have to do?
I found the adpator board on diyautotune.com where do I get the parts that you need to make this thing I already have MSII 3.0 already I got it as a assemabled kit couple months ago.
3. Would anyone be able to soder the board up for me I cant soder worth a carp. Ill buy all the stuff you need, and of corse pay someone for there time?

thanks jeff

Ya, it does give you the 2 second prime

if not useing WB 02 then there is no underhood mods needed

best reagrds

Thanks guys ordering my adapter kit 6-8-09 going to try soder it myself thanks again jeff

Here you go! Rename the extension to text to use!
These are the tables i'm using with my tune. It should get yours to start, once you put in the right required fuel.

-Brendan

This is optional - if you choose to install an engine mounted MAP sensor then you need to wire it into the Vref, MAP, and signal gnd. Use the old MAF signal wire, which now becomes the MAP signal wire. The Vref and signal ground can come off of the TPS. This mod saves drilling a hole to get the vacumm line to the MS main board. The other wires that went to the MAF can be insulated and buried in the harness.

Order the parts from digikey.com - except the donor ECM which is a junkyard item - get a '747 ECM out of a '88-'92 TBI truck - same connector and case. Follow the directions on the DIY web page. Hardest part is liberating the connector off of the GM ECM.

Brendan,

Suggest you mention the following:

engine size
injector size
base fuel pressure

as all these will affect the fuel tune....

good idea. It won't be even close to his setup.

My setup is a stock 305 from a 1989 M5 GTA
21 lb/hour injectors
~40 psi of fuel pressure.

yep, i'm far more modified as it's auto 383 HSR with 32lb/h injectors@?? fuel psi (forgot what was set up), but this will any way help me to start the engine, or maybe some one has a better tune that can share with me

best regards

How are you doing the torque convertor lockup?

i'm not sure how because first thing - not yet thought on that one, secondary i don't know if i want to use it as it is mostly racing car - so will i need it anyway ?? lock up was always thing that i do not understand how it works and why it is over there, i know it sounds funny but my tech english is very poor especialy about trans as this is my first auto car so it is hard for me to read and understand it

best rreagrds

Basically, the lockup exists to keep the transmission temps down when cruising in fourth, and give you better gas mileage.

i do not care about gas milage on this project as mostly it is racing on 1/4 mile or x-crossing , but is you can tell me how to set it up i will, maybe same day i will actually need to use 4th gear again

bers regards

The adapter board can control the TCC based on engine RPM and MAP. The control transistor is wired to MS SPR 1 on the MS 3.00 main board. Reassign one of the LED outputs (say accel) and add a jumper to the MS SPR 1 pad from the processor. Check the MS manual for more details on using these outputs.

I'm not sure that I get why the big deal about a separate adaptor for the '7730, it's the same plug, the same layout with a few minor changes in pin locations. It only takes a few minutes to pop the pins out of the harness and swap them to match the locations of the '165. I've must have gone the other way (165 to 7739, or even 7749) at least half a dozen times now. I think the first time it took me something like 30 minutes and most of that was figuring out where the pins go and the fact that I was doing it at night, in the cold, in the dark in the street while it was snowing.

One thing to note, the 37 female D-Sub connector specified in the parts list doesn't exist anymore. It's an old part number of a part that still uses led in it, and the new "lead free" version is only available in quantity 40. The part number that DiyAutotune recommended after some digging was missing the board holddowns, so I did some of my own digging and found an alternate that has the hold downs, but noticed that literally _all_ of the other versions of that connector are .054" recessed further back, I'm hoping that it doesn't matter in the long run WRT to keeping a reliable connection. (I wonder because last night I removed and fitted my GM harness connection and found that the board was cut with such tight clearances that the little bumps from where it was broken off the adjacent board was enough to prevent the GM connector from mounting).

What brackets are those that you're using to hold it down (especially the one on the left hand side that appears to hold down the plug)? Your 165 case looks different than all 3 of the ones that I have sitting around. Since the 165's used short circuit boards they usually have everything setup to mount the whole deal in one side of the case, and then you really only have a RH (the way you have that oriented) bracket that actually screws into closer to the middle of the top cover of the case. They also don't have a side opening like yours. My plug end didn't have a bracket at all, it had screws that mounted in through the circuit board which you can't use because the top one (again, with things oriented like you have in your picture) would go through one of the traces in the board), and I don't think that the top lug in the plug that your bracket looks like it's attached to is even drilled in mine.

Yours almost looks like a '7749 case which tend to have both side end end openings...

see mid-quote for answers


GM had several variations of the harness connector - the one I have here fits fine. If the bumps interfere a quick file will fix it.

http://img3.imageshack.us/i/p6130613.jpg/

http://img37.imageshack.us/i/p6130615.jpg/

With the number of pins going into the board the connector screws are not really needed I've been running the '747 adapter for 3 years with LOTs of mate/un-mates and have no problems. The RH side case opening was home brew..

I've heard a few mentions of instructions... anyone have a link? I've seen the link that points at the TBI board, but I haven't seen other instructions.

I'm not so much worried about if it will hold or not (honestly, right now I'm seriously considering machining a custom housing for it when I'm done so I don't really care that much), just that it doesn't look much like what I'm betting most people will see. I will also note that the board that I received isn't green, it's blue.

While I'm at it, I used some soldering wick to soak up almost every last bit of solder off my pins, and they still don't fit in the predrilled holes... I may try opening them a little bit but I'm a bit nervous about that since this board has tiny solder pads around those pins...

Drilling in NOT recommended - if you off even a tiny bit the feed through will not longer conduct.

Solder wick does a good job of cleaning the pins. Sometimes I wrap the wick around the pin then heat and pull the wick.

The '165 proto boards were green in color and to make it easy for DIY and end users to distingush between the '747 (green) and '165 (blue) the color was changed on purpose. The connector pin diameter should be no larger than 0.0415/0.042"

Cool Adapter!! I wish I had this 6 months ago when I built the Megasquirt on my brother's 87 IROC 350TPI. I will be getting one since I’m not satisfied with the adapter that I built. Plus I’m having issues with it..

Anyways, are any of you guys able to get a clean tach signal off the module with this adapter using the standard Hall input circuit on the MS2? I'm using a stock replacement MSD Billet distributor with the stock coil. Module is a no name one that came with the distributor. (probably the issue). I ask because in my IROC I had to build the transistor mod for me to get a clean signal off the module as described in the megamanual here http://www.megamanual.com/ms2/inputHEI.htm. After that then the car runs really good.

Would I have to uninstall the transistor mod on my megasquirt if I get this adapter or would it be fine the way it is?
My goal is to make the Megasquirt "plug and play" without modifying the stock harness in any way, only getting rid of the MAF of course

A couple of questions to clarify your ignition installation:

1) are you using a 7/8 pin hei module as per stock, with the HEI module driving the opto-isolator on the MS main board? (it appears this way but need to confirm).
or
2) do you want to run the VR sensor into the MS main board?

Note: the adapter board just passes the HEI ref high and HEI ref low to the MS main board - there are no components in that circuit between the harness and the MS main board.

If #1 is correct.

During the early adapter board development I did run an un-modified MS 3.0 main board from a GM 7/8 pin HEI module on a TBI motor (same ignition as a TPI) without any issues. I'd try it without any mod's then if you tach issues either change to the opto-isolator to a 4n26 (4n25 is standard) and the 330 ohm resistor to say 680 ohm.
The 4n26 has a much high CTR (gain) so it doesn't require as much current to turn on.

Or add the transistor. What the extra transistor does is boost the drive current to the opto-isolator.

If #2 is correct - I run a twisted shielded cable from the VR pickup directly to the MS main board bypassing the adapter, landing the VR+ into the VR input tach select jumper hole and the VR - to the closest gnd. This is how I run my own vehicle as I do not run a distributor (crank trigger with coil on plug). I put a 2 pin molex connector in series at the MS main board so I can unplug it.

Hope this helps. Let us know what you end up doing.

Another note on the '165 adapter board the Fidle output on the MS is used to control the main cooling fan - don't forget to re-assign the Fidle to turn on/off with engine temp...

Measuring my pins where they're bare and never were coated with anything (Looks like the top of my connector never got the protective laquer dip either), they seem to measure about .045-.047". At this point I've used some desoldering wick and a stainless brush to completely clean the pins before I started measuring, then I took them down a little by scraping them with an exacto knife and taking a pair of small pliers and spinning them around the pin and have gotten them down to .042-.043".

The holes in my board all appear to be less than .040" (I don't have a great way of measuring this, I'm basically doing the go/no go thing and then measuring the gauge, I'm guessing that my board holes are .038-.039").

Right now I can line everything up and slowly rock the pins in the holes by kind of pressing down and rocking back and forth... I'm guessing that what is happening is that the pins are deforming or scraping the tinning in the terminal holes, which makes me a bit nervous.

I wish I had some jewelers pin drills, then I could make something that would look like a wire wrapping tool that I could spin over the pins shaving them down slightly.

efi-diy- I hope you don't mind me posting this, if you do just message me and I'll edit the post.

I got a PM from efi-diy this afternoon about this pointing out that the connector used in the one in the pictures is actually from a '7747, not a '165, and that he has had problems with some from '165's that just wouldn't fit, and suggesting that I get one from a '7747.

While I have at least 2 '7747's and a '229 (used in '92 and up apps where the '7747 were before, physically interchangeable but different in function), I'd prefer not to destroy a working ECM I could get $50 for on ebay (the '165 I took apart was a dead ECM that I had, I think I have another dead '165 around somewhere but I'm betting that I'll have the same problem with that one).

Right now I'm seriously wondering why the board wasn't just made with .050" through holes for the connector...

The finished plated hole size is 0.0455-0.0470. The board was based on the '747 adapter (nearly identical) and the '747 connector pins are 0.040" so 0.046 nominal hole size is enough. GM made several variations of the harness connector with different pin diam. This was discovered after the boards were made. So the instructions will be updated to 1) measure the pin dia. before dismantling the ECM check for the smaller pin size and 2) to recommend using a '7747 as the donor.

0.050" noted.

I could tell you for sure that the board I received has holes that originally measured smaller than .040".

I haven't been back at the house to look at it again, is the board double sided? Does the pin have to make contact with the plating in the hole or is it OK as long as it is making contact with the pad on the bottom of the hole? I'm wondering if I push the pin through scraping off some of the plating and solder it to the exposed bottom surface if I might end potentially end up with a board that doesn't have all the contacts that I need.

I'm not trying to be a pain, but it really doesn't make sense to make a 165 adapter that requires you to dig up a '7747 for a connector. That would add $50-80 (what these things often go for on ebay and similar places, I just looked, $397.99 from autozone) to the cost of making this thing for most people.

Well, these pictures should show what's going on pretty well.

I just grabbed a TBI truck ECM and pulled it open. the first pic is the truck ECM, and you can see where the case parts and other stuff in the first pic came from.

The second pic with the connector pulled off is a '165, you can even see the heavier pins and rather large holes that it has. The aluminum piece that's somewhat bent back is a piece that is wrapped around the whole assembly and the heat sinks for most of the transistors/drivers is glued to.

Measuring the pins on the truck ecm connector I'm getting .039", and the '165 pins measure .047" measured at the same point

Either way folks need a donor ecm whether it be a '165 or '747 so the cost of the donor is there regardless. Locally the '747 sell for $30 ..

I did a random measurement on the plated hole size on 4 different boards and the smallest is 0.0455"

If the board you have is not up to spec - just send me your board so I can measure it and I'll replace it regardless of what I find. Check your PM for details. Its important to get the board back as if it is a problem I need to discuss this with the board shop.

Thanks

efi-diy:

I'm using the 7/8 pin module same as stock to drive the MS, so it will be the #1 setup that you described. I just wanted to confirm that the adapter only connects the module directly to the MS and it doesn't add anything else to the circuit.
One last question, is the module always controlled by the MS using this adapter? What I mean is while in cranking mode does the module controls the timing or does the Megasquirt?
The way I built my adapter is that I have a relay that sends 5Vref to pinB on the module so that the MS control the timing on run but not in crank. Is this the way this adapter is setup as well? Thank you for your help. I don't mean to hijack this thread but had to ask since I'm still learning this MS stuff using GM stock hardware. I swapped my 165 ECM for the 749 SD ECM on my GTA and that was very easy compared to installing Megasquirt.
I will order the adapter tomorrow and will let you guys know how it works on my IROC. I figure, I will leave the megasquirt the same to see how it works when I use this adapter.

See mid body reply for your answers... Also please use a '7747 as the donor ECM - see above posts for details on the connector pin sizes.

They run something like that at the local pick and pull type jy's, but I haven't seen one there for a long time (well, the truck ones are much more common then something like a '165). That and if you grab pigtails with them they charge you for the harness since they can't sell the harness anymore. Most of the JY's around here are not pick and pulls and charge something like $160-200 for them, so it's much cheaper for people in this area to just snag them online.

I think that you're missing my point about using a '7747 vs a '165 for the part. The part you're selling is to adapt a 165 harness, so I'd bet that 95% or more of the people buying one will have a 165 sitting around, most will not have a truck ecm around.

I sent you an email... thanks!

ok, this is how looks my one already assembled, it was made from '165 ECM, now i need to find a way to plug MAP-sensor to HSR and propably on friday i'll start to tune it

once again thanks for making this adpter

best regards

Nice, what's the little loop of ribbon cable between the 2? I take it that your 165 pins fit fine? I wonder if your board had bigger holes or your connector had smaller pins?

well my dad did soldering, he does that for more than 20 years so i think he knew what he was doing, and if he done that that means it fits cause he would't to any thing that do not fit directly, tommorow i'll know if it works when i will plug it in to the car, and the ribbon is a standard ribbon which you can find in shop with PC's - it connects MSII and adapter board, connectors are standard DB-37 but instead standard cables we used this ribbon

best regards

Have no idea why I'm not getting any emails regarding this thread....

The '7148 is physically the same size as the '7730, as it's been awhile since I had my hands on a '165/'747, but I'm pretty sure they're the same. I can have the harness connector pin out for you shortly, once I get home from work. I'm going to invite some of the Turbo Buick guys to this thread later on tonight....

Looks good man

The adapter board supports an engine mounted MAP sensor - use the MAF signal line as the MAP input. Add one jumper to connect the external MAP up inside the MS - check the assembly instructions on the DIYautotune page for details to wire up the external MAP.http://www.diyautotune.com/tech_arti...pter_board.htm <<< note this link may go broken soon as DIY is updating the '165 instructions. You can retain your onboard MAP sensor for real time baro correction the instructions are in the megamanual for hooking up the real time baro.

i couldn't wait till tommorow and just checked if it works and it works MAP in MS works fine so i'll use it as my car is MAF and i don't want to fight with any wiring anymore as i had some problems with MAF wiring, i wish it was friday already to start tune

best regards

thanks for info, i'll ask my father about that one

best regards

ok i spoke with my father (he does electrics and electronics over 30 years with his company) and he has doubdts about haveing 4 AMPS, as far as he knows DB-37 and board paths would burn even before haveing 4 AMPS as they are to small, do you have any specification on each pin how much amps goes to each pin ???
anyways as this might be a problem we are just working on connecting it directly without ribbon or cables, like shown in first post on this thread, better to prevent than heal if my father is wrong

best regards

few minutes work and my dad upgraded it by removeing ribbon which was said that might burn

2nd part of pics

so if i get this ecm set up for my 88 iroc, i can just plug it up to a laptop and tune it like the newer vehicles? do you have to change anything else or just plug it up?

You are retrofitting a more modern processor into the existing ECM housing to work in conjunction with your factory wiring harness. Since Megasquirt already comes with a SBC tune, it literally is plug and play. The only other thing left to do is to dial in your tune with a laptop....

http://www.msefi.com/viewforum.php?f...2d3f18acdcc25c

Delete the MAF. And either connnect up an enigne mounted MAP sensor or run a vacumm line to the MAP sensor onboard the megasquirt. These rest is covered in the megamanual.

so i get rid of my MAF? does this have a base tune to run my tpi? all i have to do is plug it up to a laptop with the right software and i can tune for my cam, heads, injectors, etc. sorry for all the questions, i dont know much about this stuff and i want to make sure im not biting off more than i can chew lol

yes, with adapter, you just plug to stock ECM harness, configure MegaTune and than start tuning, MAP sensor is on MSII so just make line to intakemanifold, MAF should be removed

best regards

sounds great to me, does it come with the software to load on your laptop to tune it. how much will this cost total, and who do i send my ecm and money to?