Depends which MPI!

The SEi MPI has an exhaust manifold which incorporates the CAT, The 75 doesn't.

So, for 75, a spacer is a good, easy solution.

fingers99 said:

Depends which MPI!

The SEi MPI has an exhaust manifold which incorporates the CAT, The 75 doesn't.

So, for 75, a spacer is a good, easy solution.

Click to expand...

Well its a 75 MPI going into a Seicento MPI. I was hoping to utilize the Sei exhaust.

Tricky!

The Sei cat in mani set up doesn't exactly lend itself to modification. It would be a lot easier to get hold of an SPI manifold and cat and stick a spacer in it (or extend that).

I see your thinking... need to have a chat with my local exhaust fitter i think. If they say they can modify the standard MPI to fit then fine. Otherwise The Spi manifold and cat will have to be sourced.

With regards to the injectors, can i retain the Seicentos? I'm using the Seicento inlet manifold. Do i need to swap them out for the 75 injectors or not? (flow rates different? Same injectors?)

The 75 injectors won't fit the Sei manifold. The Sei ones are the Pico type and are shorter. The Sei ones will probably so the job, but if you're using the 75 ECU, why not use that inlet manifold and the 75 injectors? AFAIK, the 75 has seperate inlet temperature and MAP sensors, while the Sei has a combined 4 pin unit.

Thanks for that info. I'm keeping the 1.1 ecu, for cost and to remove any code issues.

Does anyone know for certain if the sei mpi injectors are up to the job for the 75 lump?

Do a Google search for the code: it'll be on the injector by the connector IWP***.

That should give you the flow rate. Then this will give you a flow rate calculated on horsepower.

Current king of the helpful posts! Thats a cracking link.

If you browse my 1242 16v project, i used the sei 1.1 mpi ecu driving all of the 1.2 16v engine just fine. Ran for many many thousands of miles without even a remap. Have to extends a few connectors and wires though.


It will be even less of an issue driving an 8v mpi engine Just drop the whole 75 setup including the fuel rail and 75 injectors in.

75 injectors flow more than the sei mpi injectors so should be used. i kept the 16v injectors with my sei ecu, and they flow even more cc/min.


My motivation was the same, the code issue was easiest sorted by using the 1.1 ecu


Now I run aftermarket ecu though, as its far more tuneable.

JR also still runs a 1242 16v on stock sei mpi ecu, and has had his remapped to get more power, so its been done by a few and works fine.

My 1242 thread is in my sig, may be worth a skim read, sure theres some useful stuff in there regarding the ecu.


Kristian

Your threads make very good reading! But im hoping this build will be a little more straight forward as its my first one!

kritip said:

It will be even less of an issue driving an 8v mpi engine Just drop the whole 75 setup including the fuel rail and 75 injectors in.

Click to expand...

Using the Sei inlet manifold or the 75 manifold?

yeah, if i was doing it, i'd retain the entire 75 workings, including the 75 inlet, and just wire it up to the sei ecu.

The sei mpi inlet should fit the 75 head i think...but its easier to just use all the 75 stuff.


Kristian

how much work is involved in wiring up in the 75 inlet manifold is it plug and play on the electronics and visually it looks like it has more pipes the the sei one.

Not had a chance to look at it properly, but 1 pipe I think will be for the remote MAP, the Punto 75 has a return type fuel system, too, so there will be another pipe out of the fuel rail.

More suck it and see than plug and play: I'm pretty sure the 75 uses low impedence injectors and the MPI high, also that the 75 has a 3 pin MAP and the MPI a 4 pin one which is actually a combined inlet temp/MAP.

I thought the injectors were high impedance to be honest. The SPI ARE low impedance though, hence if you wire 4 high in parallel, the are supposed to work with spi unit Arc is the one to ask there, he must have known to set them up on his ECU.

There may be a more wires and sensors in a few places, but it's 100% doable and should be pretty easy. Just extend and rewire a few connectors

The throttle body may be heated by coolant? Not sure myself. If it is, you don't need to plumb it in as it makes no difference. The manifold is port injected so not a problem

Give it a bash, and questions, post up with pics and i'm sure you'll get some help!

Kristian

the Punto75 manifold is not brilliant. I run a Punto75 engine in my Cinquecento. It has had head work done, and the inlet is port matched to the head - but at WOT above 4k, vacuum appears in the manifold. As the revs increase, as does the vacuum. Indicating a flow obstruction.

Anyhooooo, ive not compared it to a plastic manifold.. it might be better, or might not be don't know.

Injectors are high impendence, and the TB is heated by the coolant.

arc said:

Injectors are high impendence, and the TB is heated by the coolant.

Click to expand...

Thought as much. But like i said no, need to heat the TB at all tbh.


Oh arc, I think i've found all the bits for the plastic manifold now apart from the fuel rail and injectors that I sold, so may be out of luck!


Kristian

Thanks for the continued info guys, had a look around a few scrappies so far, but I'm holding out for a low mile engine that is complete as possible. Will update when I get a lump!

That 8V? or 16V?

funking bargain if its 16V! and it does look like it too me!

Hard to tell from the pics though, as these newer blocks asthetically look a bit different. I'd imagine mount points etc would all match up.

Good price for the miles and extras, even if its 8v.

Do it!!!!!!!

They are really appalling pics, but from the serpentine it must be a 16v. Not a bad price until you remember what Aaron paid for engine and box..........