Jump to content

MPI questions

CARZSASYJ
 Share

Recommended Posts

CARZSASYJ Newbie

CARZSASYJ

Posted
Posted (edited)

Im trying to figure out wat setup ive got and wat i need to get . i have one of the last magna mpi setups from mwt and the manifold its self looks good

save that there no throttle cable bracket. the ecu tha came has a sticker on the back that says ms-5040094 and the wiring dia. that came with it says v3.0 main board ex wiring dia. ive been reading this forum and it sound like i need to mod my dist. some how, and run a 6a with a 8509?

also it sounds like i need to run bosch style injectors in the 75lb or 750cc area but low or high imp? i plan on runing .040 over with wiseco pistons,

dads manarl head setup for mech., and a 19c. but im kinda new to conquests and any advise or help would be greatly appreciated.also trying to figure out wat wiring i can remove

 

Thanks

Matt

Edited by CARZSASYJ
Link to comment
Share on other sites
shift1313 Newbie

shift1313

Posted
Posted

it sounds like you have a megasquirt ecu v3.0 which has a piggy back board on the pcb. I believe you can run low or high impedance injectors depending on how the ecu was setup. I cant recall if its in the settings in megatune or a resistor setup on the board.

 

you can run the ms unit with the stock ignition system. the stock ignition system is seperate from the fuel computer. but there is tons of info out there. Also with the megasquirt you can run distributorless.

 

does the car not run? whats the deal with it?

 

and welcome aboard.

Link to comment
Share on other sites
CARZSASYJ Newbie

CARZSASYJ

Posted
  • Author
Posted

wats the pcb? is the imp. the same as resistance.how do u tell wat it was setup for ? i wanted to run mpi i hate the tbi setup. also i dont really wanna deal with coil packs it seems complex so i think i wanna keep the dist.

 

the car lost conrod bearing 4 and starved the turbo and motor for oil. it didnt seize but made a nice dent in the cly wall hence the .040 over. the motor should be back from the mach. shop later this week. plan on putting pics on tonight.

Link to comment
Share on other sites
shift1313 Newbie

shift1313

Posted
Posted

the pcb is a printed circuit board. The board that all the electrical components are soldered to. This circuit board will have info printed on it like www.megasquirt.com and bowling and grippo also V3.0 on there. Megasquirt is a do it yourself ecu.

 

impedance and resistance arent the same thing. a low impedance injector will usually have a resistance between 2-3 ohms and be used with some sort of ballast resistor pack with a factory ecu. High impedance injectors usually are around 12ohms resistance. It all depends on the injector driver. Most aftermarket ecus are setup to run low impedence injectors and the resistors are built onto the board instead of a seperate resistor pack.

 

Impedance technically has to do with opposition to ac current. Injectors are just simply a solenoid or electromagnetic valve. because there are windings which make up this magnet the term impedance can be used to describe the way in which the injectors are built. The issue with resistance comes from the relationship V = I R. If your voltage stays the same(in your ecu) and it is supposed to supply a 12ohm injector, the current is 1amp. Now that same ecu think its supplying a high impedance injector but really you only have 3ohms of resistance now you have 12/3 or 4amps. thats enough to fry your ecu if your not careful. Our stock tbi cars run a 6ohm ballast resistor pack in line with the injector ground from the ecu.

 

Now having said that, i dont know which you are to run but a search on a megasquirt forum might give you the answer.

 

www.msefi.com

 

I know ms1 v2.2 needed resistors depending on which injectors you used, but i believe v3.0 used a flyback which did not require additional resistors for the injector drivers. but i do not have any experience with this so unfortunately i cant give you the answer.

Link to comment
Share on other sites
substock Rookie

substock

Posted
Posted

the best thing you might be able to do to figure out what the ecu is programed for is connect the ecu to your laptop via the stimulator and save it so we can check it out.

 

you could also open the case up and snap a pic for us to see. maybe someone can identify it

Link to comment
Share on other sites
substock Rookie

substock

Posted
Posted
the board says v2.21 all over it but the wiring dia. says v3.0 ? have higher quality pics but there to big. oh and i just noticed the the main chip says "msv30 bg"

 

that is the 2.2 board, and just from looking at it, it is not setup for any ignition control so it would be a fuel only ecu.

you would be able to leave the stock ecu in place and have it only control the ignition. or remove it and use an msd or equivalant.

 

also, what size injectors are you planning on using?

your ecu doesn't have the flyback board installed, so if you wanted to use low resistance injectors you would either need to get the flyback and install it, or run resistors inline for the injectors.

 

here is a pick of mine, the flyback board is attached to the top of the case on the right

http://i97.photobucket.com/albums/l225/substock/Misc/DSC00211.jpg

Link to comment
Share on other sites
shift1313 Newbie

shift1313

Posted
Posted

i would agree that is not a v3.0 setup. on that msefi site link they show pics of the different versions.

 

i believe they are up to a version 3.57

 

here is a v3.0 setup

 

http://www.diyautotune.com/images/ms230/ms230-c_2.jpg

 

you can see the extra little board where the chip should be. it runs a 24mhz processor. the older versions can upgrade to this add on board as i think it just plugs into the chip socket, but i havent researched it in awhile.

Link to comment
Share on other sites
CARZSASYJ Newbie

CARZSASYJ

Posted
  • Author
Posted (edited)

it seems like the msd is the way to go? not sure wat injectors to go with. seems like most go with 75lbish. is lockin the dist just disabling the vac. adv.?

 

so the ecu and its whole harness could be removed? it doesnt do anything besides the engine? thanks for the info on the ms now i just need to figure out how big and wat style injectors and the resistor setup. or get flyback?

Edited by CARZSASYJ
Link to comment
Share on other sites
shift1313 Newbie

shift1313

Posted
Posted

there are a bunch of additional features built in to the newer versions. you can see a lot more drivers built into the newer version. They have integrated things like stepper motor control for idle, the flyback circuitry is built into this board so there is no add on to run lowZ injectors.

 

also the blank unpopulated area right next to the small circuit board is a proto area they added so you can add on any stuff you want.

Link to comment
Share on other sites
CARZSASYJ Newbie

CARZSASYJ

Posted
  • Author
Posted
there are a bunch of additional features built in to the newer versions. you can see a lot more drivers built into the newer version. They have integrated things like stepper motor control for idle, the flyback circuitry is built into this board so there is no add on to run lowZ injectors.

 

also the blank unpopulated area right next to the small circuit board is a proto area they added so you can add on any stuff you want.

 

 

but ive already got the other one

Link to comment
Share on other sites
substock Rookie

substock

Posted
Posted
it seems like the msd is the way to go? not sure wat injectors to go with. seems like most go with 75lbish. is lockin the dist just disabling the vac. adv.?

 

so the ecu and its whole harness could be removed? it doesnt do anything besides the engine? thanks for the info on the ms now i just need to figure out how big and wat style injectors and the resistor setup. or get flyback?

 

i might have a pair of 65#'s

 

i'll have to get back to you though

Link to comment
Share on other sites
shift1313 Newbie

shift1313

Posted
Posted
it seems like the msd is the way to go? not sure wat injectors to go with. seems like most go with 75lbish. is lockin the dist just disabling the vac. adv.?

 

so the ecu and its whole harness could be removed? it doesnt do anything besides the engine? thanks for the info on the ms now i just need to figure out how big and wat style injectors and the resistor setup. or get flyback?

 

As far as i understand(i havent tried it) the ecu controls only fuel, the knock box setup does ignition, and the etacs computer does the other features in the car like alarm.

 

If you run high impedance injectors there should be no need for modifications to the megasquirt. Its only lower impedance injectors that require the resistors of flyback mod.

 

if you search around online there are tons of fuel injector calculators. You can probably get away with 550cc injectors. I think the stock setup total is about 1600cc.

 

the stock dist uses mechanical advance via weights and the vac advance/retard setup which advances the timing under vac, but once boosting it retards the ignition. I believe its advance 11 degrees and retard 7degrees but i cant remember for sure. As far as disabling the advance, ive never done it so sorry i cant help you there.

 

 

if you decided you wanted to upgrade for the different tables, and some of the other upgrades here is the link

 

http://www.diyautotune.com/catalog/cpu-meg...board-p-86.html

Link to comment
Share on other sites
shift1313 Newbie

shift1313

Posted
Posted

the newer ms has better power control built in. the issue of running lowZ vs hiZ injectors comes into play with current, when you start adding resistors inline you slow the reaction time of the injectors. the benefit comes from spray pattern, peak and hold and saturation. It is said that you can run a larger size Low Z injector and have better control over it at lower rpms(like idle) than a high Z injector. It was thought that high Z injectors over 50lbhr were hard to control and had poor reaction and bad peak/hold.

 

With new injectors out there are tons of good quality high Z larger injectors that you can get and probably have no issues. I say probably because i dont have first hand knowledge of this, its only from reading. I think for a lot of people its what they can get their hands on for a good price. A few resistors are cheaper than injectors:)

Link to comment
Share on other sites
StarquestRescue Newbie

StarquestRescue

Posted
Posted
i was looking at my intake last night and realized a fun fact. it doesnt have the bracket for the throttle cable on the side and the tps touches the fuel reg.

anyone have any ideas?

Some guy do this.

http://i237.photobucket.com/albums/ff45/StarquestRescue/DSC00361.jpg

 

http://i237.photobucket.com/albums/ff45/StarquestRescue/DSC00363.jpg

 

Some guys have the throttle cable on the other side.

 

The radius on the throttle cam in the picture only gives me about haft the petal travel of the stock cam.

 

I am in Lancaster PA. I just started mocking mine up on a parts car.

Link to comment
Share on other sites
  • 2 weeks later...
 Share
Go to topic listing
×
×
  • Create New...