Hi looking for an engine guru / advise for my Sei 1.2 8v track car.... would like to see if I can get anymore out of it... Its running a de cat exhaust, induction kit, hot cam.. standard TB .. it's nippy enough more mid range than top end.... it seems to struggle past 4500 rpm .. like it's lean.. thought please.. my old 1.1 sporting used to like been reved... this semms to tail off ?? .... Thanks Ade, Im based in Lancashire thanks

Put it on a dyno with an afr probe.

All the modes you did should make is breath better, might need more fuel... bigger injectors, higher fuel pressure, bigger fuel pump...etc etc

Yeah thats what im thinking.... will have a ring round and see if i can find a decent place.... most places just want to down load maps these days i need someone old school that knows fiat ?

Your'se is a later mpi. You changed the complete engine or just a 1.2 bottom end?
Maybe a 1.2 tb from a panda 69hp. Or switch to the old p75 mpi setup with alu intake and 40(or bigger) tb.
What cam do you use. and how is the rest of the exhaust?
Port and polish the head. Thinner head gasket so many options.

At least you did the important upgrades first, tires brakes cage etc

Is the current ECU tunable?
If it is, that would be the best way to go about it.. put it on a dyno, with AFR meter, do a few base runs, and go from there.. maybe it needs more fuel higher in the rpms at WOT (that is my feeling according to the description).
A custom map on a dyno.

The mods you did should make it breath better at higher rpm's ... The ecu will not be able to compensate if the extra air goes in mostly in WOT.

You might be able to go around that by playing with different size injectors or fuel pressure,.. at the same time ..the ECU might compensate for the bigger injectors taking you back to the beginning.
No real way of telling if you don't have an AFR gauge.

This is what i think is happening: (only that you are not actually getting the extra fuel required at those high RPM's)


The same that same graph could be used for the AFR as well:


It is probably lean for high rpm/load/ WOT but might still be to low to actually trigger a lean condition error...or the ECU might just ignore it since it's in open loop anyway.

Yes its a full 1.2 8v MPi conversion.....if it is re-mappable how can i find out ? ... but yes feels like the mixture is weak at high rpm (over 4000 RPM).

Some more pics

Ady117 said:

Yes its a full 1.2 8v MPi conversion.....if it is re-mappable how can i find out ? ... but yes feels like the mixture is weak at high rpm (over 4000 RPM).

Click to expand...

Read the ecu's name then Google

Start off with a bigger, or multiple throttle bodies.

Also bolt the main hoop to the b-pillars.


Where abouts in Lancashire are you?

The previous seller didnt have a clue about the cam, just claimed it was a piper, take the coil pack holder off and see if theres any stampings on the end of the cam.
A 'hot' cam should just be coming on at 4500 and pull to the limiter, not struggling.

I have to say the car has nice low and mid torque ... but it just tails off... it's not that big of deal.... its just that last little bit it should be on song. Im based in Padiham

Definitely stick a bigger throttle body on and check the timing is spot on.

Brooky said:

Definitely stick a bigger throttle body on and check the timing is spot on.

Click to expand...

40mm MPI throttle body,


I can mod. the MPI TB to 40mm.

sparky ! super can i post you one down ?... email me at [email protected]
that would be great, i will look into the timing ... are we talking vernier cam Pully or ignition timing ? im pretty new to fiats but adore it !... here is a picture of the cam end that people have asked about ... anyone shed a light on it ??

Talking cam timing. If the gead has been skimmed to raise the CR then the timing will be slightly out using the standard pully. Piper do an spi vernier pulley and I'm sure Cat Cams do both the mpi and spi.

That is a reground camshaft by Piper, good luck on finding any info on it though, ive just got my hands on one too and done the rounds. They don't have any records of them...but can measure it for you, at a price.
'Fast road' profile yours will be.

The main issue you have is the Ecu. You will not find any place to remap the MF59. These have tight tolerances for emissions so I am surprised your injection light does not flash on some times with that 270 cam.

Changing anything on the fuelling side will throw things out even more so look at a piggy back Ecu before anything else.

Been in touch with the guy that bought it new and built it.. yes as you said its a Piper, 3/4 cam, yes looked into verneir cam from Piper and i wouldn't have a clue how to time it up.... its not been skimmed, but looking into may be getting skimmed and ported, would be great to get a 40mm body.

yes ECU flashes up on steady part throttle but it's no Cat either but flat out its cool rev limiter is apx 6500...

Check the timing belt pitch before buying a pulley, theres two different types.

I"d go for the 40mm TB from sparky l, cheapest option when compared to a pulley or piggy back ECU

P.s it should rev to more than 6500!!

as said check the timing first and if it has a pulley set it to 0.
Maybe find someone who knows how to setup a fire engine