Technical Megasquirt

[davethetrike]

if you could get me one of them idle control boards, that'd be handy.

can you get confirmation on how the TDC sensor is wired. Looking at the FIAT specs, the TDC has a signal + and a signal -. can you confirm with Bill about if the signal - is to be tied to ground, or to pin7.

As soon as I have a price I'll let you know. posted it up quick because it could save us lots of hassle.
I'm waiting for confirmation that the 'final' wiring diagram is correct. I'll ask in the reply, up to now he has always responded on the same day, usually very late.

 

[Asteris]

Update on Punto fitting:
Firstly, Bill's just let me know that the stepper board to convert pwm to control appears to be working, he's letting me know the price.
Secondly, I'm trying to sort my wiring and come up with a 'standard' for mk1 puntos. We (Bill and I,well mainly Bill )should have a working diagram by the end of this week. Obviously, it might not happen, also it won't fit centos. It will provide a guide for use with fire engines using the relevant wiring diagram. I'm only posting this in case anyone else is struggling (as I am) to get this right first time, an answer might be available soon.

If it fits a Punto 55/60/75, it also fits a cento. We have the same engine harness, excluding the 4 injectors of the 75 instead of the one all the rest have.

 

[davethetrike]

If it fits a Punto 55/60/75, it also fits a cento. We have the same engine harness, excluding the 4 injectors of the 75 instead of the one all the rest have.

There are a few detail differences I'm afraid,For example the mpi has 2 pin outs to the injectors - makes sense.

pin 26 is a live feed in on the spi but not an mpi

and there may be others..I don't think they're major or problematic, just that there are differences. I'm also not being put in a position of saying wire it like this and it will work - I'm not that dumb or clever .

What's happened is -
I've worked out what I think is correct and sent it to Bill.
Bill sends it back saying changes I needed to make and that a stepper board is available.
I've sent it back for Bill to check, hopefully he'll check it and send it back and say yes, or maybe 'change this'.
I'm not posting it up yet because it might still be wrong, in which case someone could wrongly assume its ok and screw a megasquirt or, worst still ,themselves.
Bill hasn't indicated that he is charging me for this service (I bought my system from him and he says -part of the service-) so I'll be patient and wait.

When and if Bill says fine then I/we have something to work from.
If he gets busy or 'gets a life' maybe we can knock it about on here and sort it.

In short, yes it will work on all- maybe. But its not gonna be me that says it will definite

 

[Asteris]

Punto 75 has 1 pin to the 4 injectors (they are connected in parallel) and so does the spi one. I have the punto 75 engine on an spi harness and works fine (just changed the single injector with the four ones). Punto 85 has two different sets of injectors, so two pins.

Pin 26 is live at spi, but that is from the ECU part. We won't use the spi nor the mpi ECU, we use MS. So we connect whatever we want to pin 26, usually +12V and let the MS ground the other end (pin 23) whenever it wants to power up the fuelpump/injectors/coils/lambda heater.

 

[davethetrike]

Punto 75 has 1 pin to the 4 injectors (they are connected in parallel) and so does the spi one. I have the punto 75 engine on an spi harness and works fine (just changed the single injector with the four ones). Punto 85 has two different sets of injectors, so two pins.

Pin 26 is live at spi, but that is from the ECU part. We won't use the spi nor the mpi ECU, we use MS. So we connect whatever we want to pin 26, usually +12V and let the MS ground the other end (pin 23) whenever it wants to power up the fuelpump/injectors/coils/lambda heater.

Sounds like you've got it sorted
Any chance of you sending your diagram and we can compare notes?

 

[Asteris]

When I replaced 1.1 spi with 1.2 mpi, i just cut the single injector, soldered the 4-in-parallel mini injector harness, replaced the 16F with an 8F unlocked Punto75 ECU and started the engine.

When i get home, i'll post an mpi harness diagram, from Autodata CD. There is also another one from Haynes 1.1 spi, which might gets handy.

 

[davethetrike]

When I replaced 1.1 spi with 1.2 mpi, i just cut the single injector, soldered the 4-in-parallel mini injector harness, replaced the 16F with an 8F unlocked Punto75 ECU and started the engine.

When i get home, i'll post an mpi harness diagram, from Autodata CD. There is also another one from Haynes 1.1 spi, which might gets handy.

Things don't work like that for me

Stepper boards will be £30 ish don't hold your breath though as he has to get components etc and be happy with it all. Should know the wiring bit by the weekend, fingers crossed.

Always feel like an imposter from the Punto forum :devil:

 

[Asteris]

Here are cento and punto diagrams.

 

[Asteris]

Stepper boards are 30£, MS-II processors are 65£. And now MS-II does have toothed wheel and second coil support. Plus native 4-pin IAC control. And 0.001ms injection resolution. And more...

Do your choice wisely.

I have my MS-II ready and waiting for the second VB921. Starting to build my harness...

 

[davethetrike]

Here are cento and punto diagrams.

They're wrong, Just had an interesting conversation with Bill it appears the Autodata (yours) and the Fiat Diagrams (from the fiat manual - mine) disagree.....So Bill is now unsure of what is correct. Therefore he cannot currently agree the wiring. Until he's checked.

Even something as basic as the mpi layout is wrong,on yours, as the injectors have 2 feeds not one

However, it appears it can be made to work! me? I'm just totally confused ........

Think I'll sit back and see what's happening...

 

[Asteris]

Diagrams are ok. The only punto that has two set of injectors, is the 1242 16V (85hp). Punto 75 has one set of 4 injectors, driven by pin18 of the ECU.


Cento sporting 1.1 Spi and Punto75 mpi have 99% similar harness. I know it because i installed the 1242 75hp mpi engine in my Seicento sporting 99 1.1 spi and the only things changed was the replacement of the single injector with the four of the Punto plus the connection of pin 26 to a switched +12V, as the Punto ECU had no immo. Kept same lambda, rpm sensor, MAP, MAT, TPS, IAC, changed only into Punto CLT, due to different manifold shape. ECUs have the same pin arrangement, one by one, checked it myself a lot of times before i started engine transplant.

What type of Punto do you have? Is it a newer MPI model (99-) we are talking? These do have differences over first models, but then yours should have different ECU, not 8F or 16F i am talking about...

 

[davethetrike]

Diagrams are ok. The only punto that has two set of injectors, is the 1242 16V (85hp). Punto 75 has one set of 4 injectors, driven by pin18 of the ECU.


...

And there you have it.
As you say minor differences, however, I'm using the 85 loom not the spi which explains why you and I are seeing different things. When you say mpi you are refering to the 75 I am refering to the 16v. Immediatly we have a discrepency. However, in most other respects the looms look similar - do you want me to cross check the 16v with the 8v loom? The Fiat manual doesn't even show a separate 75 mpi loom:bang:

How's your loom building coming? I understand from Bill that you have solved most of the problems?:worship:

I can see why you went ms 2 but, most of us were advised to avoid it. If you get it working I might sell the ms 1 and buy an ms2!

 

[Asteris]

In this case, just connect spark B to pin 33 of the loom and use two squirts/alternative injection pattern. I may also do this, by wiring the extra cable outside of the harness.

How did 85 harness end in your hands? I see you have an 75 engine, isn't it?

Loom building starts tomorrow. I'm also short of the second VB921...

 

[randomizered]

No, that is a 16v 1.2L engine, see the sig, there are 4 valves per cylinder.

Dave is putting a 1.2 16V into a Punto along with a supercharger, and NOS, his thread is here

There is very little diffence betwen going from a 1008 or 1248 to 16V

Kristian

 

[Asteris]

Here in Greece we say, "you see the tree but miss the forest". Instead of looking his sig, i browsed his gallery and saw his previous 8V engine... :bang:

Hopefully we found a solution...

 

[davethetrike]

Here in Greece we say, "you see the tree but miss the forest". Instead of looking his sig, i browsed his gallery and saw his previous 8V engine... :bang:

Hopefully we found a solution...

Hey, nobody is crazy enough to fit a supercharger to a 16v in an 8v car are they
Or the 16v in a cento....

I'm ok, just a bit fed up 'cos I'm going round in circles with megasquirt

And it now appears that someone who is crazier than me has all the answers!!! That's you Asteris Smile we're on the same side.

Good luck with the loom (harness) because I'm totally

I have the fiat wiring diagrams in adobe format. Let me know how and I'll forward them to you.

 

[davethetrike]

In this case, just connect spark B to pin 33 of the loom and use two squirts/alternative injection pattern. I may also do this, by wiring the extra cable outside of the harness.

How did 85 harness end in your hands? I see you have an 75 engine, isn't it?

Loom building starts tomorrow. I'm also short of the second VB921...

Yep done this bit...
tomorrow I'll send you my take on the wiring which I know is wrong because Bill states the MSquirt must control the relays to the fuel pump. Its as far as this old dumb brain goes. I can't post it here in case someone in the future looks and wires theirs to my plan:bang:

 

[davethetrike]

I sent the wiring diagram to Asteris to check last night and after a 2 amendments he agreed it looked good.
Thanks Asteris:worship:
UNTESTED -DISCUSSION ONLY
Most of the wiring diagrams look similar and if you follow the schematic you can trace where each punto ecu (ecu) connection is made and trace it from the megasquirt through. Check against your own wiring diagram. The loom and ecu that this is designed to connect to is in the Haynes. Pin 33 goes to the second pair of injectors on some mpi units but is unused on the spi.

So

 

[eskimo_god]

When I replaced 1.1 spi with 1.2 mpi, i just cut the single injector, soldered the 4-in-parallel mini injector harness, replaced the 16F with an 8F unlocked Punto75 ECU and started the engine.

you might be able to hep me i am planing to convert my 1108 spi to a mpi using a unlocked 75 ecu with plans in the future to run it on megasquirt.

slightly diferent to you but but sort of the same thing would i need to change the 16f to an 8f do you know also what is an 8f-16f?

 

[Asteris]

That's exactly my route. Changed from 1.1spi to 1.2mpi and now to MS-II. Which by the way has an MS2Extra new release.

16F is cento spi ECU and 8F is punto75 ECU.