Toehead

Just a quick question... How do you integrate the megasquirt to control the stock ignition timing?

91RamAir Formula

it wires right in to the factory wires depending on your setup. check out the site for more info.

jayk2k3

iTrader: (2)

quick question. if i want it to only control fuel, do i still need to remove the bias resistors?

mhaskell

If you share the factory guages with the ECM yes you have to remove the ECM, if the sensors go to the megasquirt only then no.

D's89IROCZ

dugging up the dead here.

What I want to accomplish is keep the stock ECM ( 165 w/ MAF) But I want the Mega squirt also . Is there a way to have them both ? I just want to buy it plug it in and go ( disabled after a work place accident and can;t really do much now ) . I seen there is a wireing harness you can buy ??? Will it just plug into the stock ECM and the Mega squirt? Also this will be for a turbo'd setup that need boost managment ( like fuel changeing vs. boost)

thanx all

ChevelleFan

iTrader: (4)

Why would you keep the stock ECM (MAF) and install a Megasquirt (MAP) ? Also, if you really want something that you just plug in, frankly, Megasquirt is not for you. It's a very DIY product.

D's89IROCZ

I just read the previous posts and they say you can buy one built already . Then there is also a harness you just plug in. I already have a prominator PRO , I just want some boost managment. What makes this harder than the Prominator install. I maybe misinterperating the post that said you can buy a already built harness ?

91RamAir Formula

There is prebuilt generic harnesses's but nothing specific for out cars, check out http://www.bgsoflex.com/megasquirt.html for more info. Hope this helps but we will help as much as possible.

D's89IROCZ

well I have alot of reading to do now I appreciate the link .

BTW Do our ECM's have only one bias resistor or two ? I have the 165. If I have only one I can piggy back it tp the stock ECM it says on that site.

ChevelleFan

iTrader: (4)

The previous poster had it correct that there is nothing specific available (that I've seen) for plug-n-play installation into a thirdgen.

The harnesses that you're reading about are usually just a bundle of wires that are presoldered and assembled to the DB-37 connector. The other end of the wires are bare -- ie, no injector/TPS/CLT/IAT/IAC connectors. Places like diyautotune.com and rs-autosport.com sell these Megasquirt-releated wiring products. In another post a year or so ago, I think S10Wildside said he could make a harness with the injector/TPS/CLT/etc connectors, but the other ends would be bare (and need to be soldered into a DB37 connector), Or you buy both the MS harness and one like S10Wildsides and splice them together. Either way, there's work involved.

-Dave

D's89IROCZ

I see . So basically them connections you listed are all that have to be dealt with ? I still am reading on it a bit for now .

ChevelleFan

iTrader: (4)

You will specifically have connections for

Power
Ground
Injector +12v
Injector bank 1
Injector bank 2
Throttle position (TPS)
Coolant Temp (CLT)
Inlet Air Temp (IAT, sometimes referred to as MAT, Manifold Air Temp)
O2 sensor (narrowband or wideband)
RPM input (tach input)

Optional: Ignition output signal (if controlling ignition timing) and IAC (Idle Air Control). IAC only works for the MS-II processor.

You're right, you have plenty of reading to do. Start at http://www.megamanual.com

-Dave

91RamAir Formula

Dont's forget your 5V common for TPS and IAT i believe

Toehead

I'm planning on putting in my megasquirt fairly soon... Anybody know and hints on configuration (good starting values) for a 5.0 TPI

mhaskell

I have a decent map for a 350, play with the required fuel and it will be pretty good for your car to get going. Whereabouts in mass are you? I'm in the attleboro/providence area.

pizza_guy

Sorry, wrong thread.

91RamAir Formula

What version of megasquirt are you running and what software version? Are you planning on using spark control or just fuel?

Toehead

I'm ordering a Megasquirt II pcb 3.0 as soon as I get out of school. I already bought the engine. It came with a stock harness, but I figured it might be better to start fresh with something that I can more easily configure.
the engine is an 89 5.0 TPI out of a GTA.
I am currently in North Dartmouth, MA... I'm a mechanical engineering student at UMass Dartmouth. When school is out, I live in Townsend, in the Lowell- Fitchburg area.

Toehead

At this point, my main concern is seperating all the ecm wiring from my dash wiring. i have a berlinetta, so everything is very specific and a bit funky. This is one of the reasons I want to go with the megasquirt. I think I will start by pulling out the ecm and extracting all the wiring from the main bundle. Does anybody know how the berlinetta tach signal reaches the dash? it is important for me to preserve the tach functionality (even if it reads incorrectly ) because I don't want a dead tach on the dashboard. In an 85, how intermingled are the ECM and Cabin wiring harnesses? I am no stranger to automotive wiring and am not leery of rewiring the engine at all. However, i would prefer to not have to tak out the entire dash assembly to rewire it. Thanks!

91RamAir Formula

The best thing you can do is go on ebay and find a factory service manual for your car it's the best way to figure out the factory wiring mess I could not have done my megasquirt without one.

Toehead

They don't exist, or are very hard to come by for my car.... Looks like ill be doing it the old fashioned way. Multimeter ho!

91RamAir Formula

well on my car which is a 91 and a firebird all the engine harness went through the firewall on the passenger side inside the fender and all the other crap ( interior, cruise, lighting, etc.) went through on the driver side, not sure if yours is the same but hopefully this will be a little help.

Toehead

I got the megasquirt and assembled it. It is on my bench right now going though a "burn in period"... I figured it would be appropriate to let it run for a few days outside the car to weed out any problems.

Do you still have your 350 tune? I would love to have a baseline to tune from!

ChevelleFan

iTrader: (4)

The base VE map in Megasquirt is for a stock 350 TPI.

Toehead

well, that makes things easier...

Toehead

3 days running, not a hiccup yet. I have the MS II v 3.0, already played with the tune to compliment my target engine... .Now just to get it actually in the car so that the EGO can work it's magic to my cruise MAP zone.

Toehead

Getting ready to wire everything up. What did you fellas do about the purge solenoid?
I assume it functions off of a PWM signal.
In that case, I should probably block it off. I am interested in other ideas however.

formula350sd

iTrader: (2)

I have a dumb question has anybody here put a megasquirt in a 165 ecm car using the factory wiring and if so how much of a pita is it if they could share any experience it would help me out greatly

thanks
AL

91RamAir Formula

Toehead are you referring to the charcoal cannister purge solenoid? if so I just removed my mine.

Toehead

Yes, I was....
I will probably just remove it completely and cap the ends.

brad36002

Alright guys heres a biggie that i need some serious help with ... the only way i know to do this is to tell you what im doing and you tell me what i need to do/and get from diyauto ..

1986 Mazda Rx-7
V8 swap ( 88 5.0 roller )
custom upper intake with 75mm throttle body ( runing a throttle positioning sensor , not map or maf )
347 stroker ( forged internals)
ssautochrome T-60 Turbo


i already have a brand new Dell laptop so im good there but i need to know what to get as far as my Megasquirt , and if there is tuning maps for this kind of set up .... im hoping to run about 20 to 25 psi and crank out around 700HP ... i know its alot to ask of you guys but ive read many many post and you guys know what your talking about ...thanks in advance


Brad

Toehead

Hey there!


Thanks for diggin up this thread; It bring s back memoies!


I ran the whole summer on the MS with no problems.

AS for your setup, there are many many people running your setup on MSEFI.com. You should talk to Jim, he will set you up with a base map. You will also need the MS and a wideband. The megasquirt with the wideband will tune itself. You specify an AFR ratio vs map and RPM, and it will change the VE table to match the AFR you specify. Jim can also set you up with a good baseline AFR table.


After that, it is just street tuning.


You should get the MS-II v 3.0 (DIYautotune)
Stimulator
Wiring harness
Wideband

LOTS of time and patience. I had a great deal of fun making my megasquirt. it took about an 8 hour saturday to get the board constructed. They sell a surface mount version if you would rather not do the soldering yourself, but I found it to be very educatuional, worthwile, and cost-saving to do it myself.

91RamAir Formula

another question he fergot was what are you using this car for strictly track car, street/strip, road coarse? it sounds like your wanting to run Alpha-N which is what it's called without a Map or Maf but the megasquirt comes with an onboard map. But everything else toehead said sounds right on the money.

Brian Esser

[quote=mhaskell;2787144]I am running stock gauges, MS can share sensors with the stock ECU no problem.
quote]

No always. Especially with some GM varistors.

spills

iTrader: (9)

I've got to chime in on this one. I just bought my MSII V3.0 Monday, and just got it all put together last night. I had a few hickups, but the MegaManual has an INSANE amount of info. Im still a little confused on wiring a 6A and 8pin HEI with a VR trigger instead of Hall, but thats another thread.

Also just wanted to give a HHUUGGEE thumbs up to DIYAutoTune!!! Come to find out, they're just down the road from me. So I went by to pick up my kit and while I was there I was talking with some of the R&D/tech guys there. They were even telling me that they are working on a Foxbody 5.0 plug-and-play converter. Guys were awesome, very knowledgeable, very willing to help out with any problems, all around just a great company with a great product.

Toehead

Ya,

I ordered my kit and it had shipped within the hour.


They have also been nice enough to give me, at their expense (even shipping!) , small parts that I have needed (processor pin, etc.)


They are really the model vendors. I wish more companies would live up to their example.

runningagain

How does megasquirt differ from dynamic efi.

spills

iTrader: (9)

I cannot say from experience what the main differences are, but from my experience with just the MS, it's an amazing amount of tunability for the money!! if you get the MS2, you can control fuel and spark, 2 stage nitrous control (I believe that's still in the beta version right now), "auto" tune capabilities based off volumetric efficiency tables, set rev limits, and alot of other tuning parameters that I cannot even begin to understand. Honestly though, if you are even slightly interested, start reading HERE. It might look complicated at first, but if you have a good understanding of how a motor works along with fuel injection and ignition components, the MegaSquirt can be your best friend.

Another pro: if you're driving down the road and feel that you need to change the timing a little, or adjust your fuel map a bit, just pull over, turn motor off, tune, burn, crank'er up and you're done. All tuning can be done from inside the car, no need to buy an expensive tuner or take the ECM out to hook up to your computer or any crap like that. Just get a cheap laptop and that's all you'll need. Again, this is my first DFI ECM Ive had, but so far I feel no reason to choose any other. Ive got less than $400 in my setup including the ECM itself (I had to assemble, which was kinda fun and educational), stimulator (hooks up to ECM when you want to tune it outside of the car), and wiring harness with labeled and color coded wires. Cant ask for more for that kinda money!

Toehead

You don't even have to shut off the motor to tune

Just have a spotter to grab the wheel and do it on a back road lol

runningagain

That sounds great, I have an 86 truck that had an 86 TPI, it never ran right so I replaced everything, still don't run right. Time to do something about it! What system do you have, I know there are alot of versions out, I want to control it ALL.

Toehead

305 or 350? If it is a 305 I have a really good tune ready for you

MS-II will do everything you need except EGR and the purge solenoid.

runningagain

I was told it was a 350, I have the numbers off the block but can't find the info I need to tell, would that make it run BAD.

spills

iTrader: (9)

MegaSquirt II V3.0 motherboard. Thats what Im running currently with the 2.88 code.

Not to get off topic too much, but what do you mean you cant get it running right? Id find the source of the problem first. Otherwise when you install the MS you wont know if you tuned something wrong, or if there is a sensor that needs to be replaced. Just a good overall idea to put the MS on a good running motor, less headaches in the end.

EDIT: If you've got your casting number, go to www.mortec.com , they've got all kinds of head and block casting numbers that should help you figure out what youve got. There's other ways of telling, but to me this is the easiest

runningagain

I have had the truck for about two years, when I got it the harness looked like a rats nest, so for the next month I straighted out the harness and got it running. It ran ok but the idle was rough but power was good. After taking it to many shops I have changed All the sensors, still has a problem. Then I changed the cam, intake (Holley stealth), harness, distributor, injectors, now I drove it and got a code 45 rich exhaust. I started looking for diagnostic software and ended up here.

runningagain

I have posted on "what's wrong", I will figure it out first, I thought that megasquirt would show values to diagnose my problem with, thanks for your input.

spills

iTrader: (9)

ehh, its hard to say. I would imagine that the MS would help you in diagnosing you problem, but Id still say try to fix your problem first, or at least find out the cause, then install MS. 99% of idle problems Ive had with my cars have been some sort of vaccum leaks. Broken/disconnected hoses usually, I even had one incident where the carb flange was slightly warped causing a vacuum leak! I had to double stack the gaskets to fix that one.

runningagain

When I still had the original TPI intake I checked several times for vacuum leak, I used a vacuum gauge and it read 10-12 inch, I thought that was low. Last resort I changed the intake and the throttle body, still low vacuum.

spills

iTrader: (9)

If memory serves, I think stock TPIs pull about 18" at idle? I cannot remember, maybe someone can correct me. If that's the case, you've got a leak somewhere. Check to make sure all hose barbs are either hooked up to good vaccum lines or capped off. Let us now how it turns out

Didnt you say you put on a stealth ram? Make sure ALL the ports on the back of the upper plenum are either sealed off or are in use. DId you put on any sort of RTV or gasket between the upper and lower plenums?

ChevelleFan

iTrader: (4)

I don't think you're supposed to use any RTV between the base and the plenum. Maybe just a little gasket bonding stuff to keep the paper gaskets from sliding around.

-Dave

spills

iTrader: (9)

Ive talked with a few guys who didnt wanns wait 2 days for Summit or whoever to ship the gaskets, so they just RTVd them I used the gaskets on mine, RTV gets messy sometimes