N/A SPI 998cc
Turbo Mini Forums

Ive just installed the SPI setup on my 998cc
Im running MS1 V2.2, with EDIS

Ive got it to IDLE but as i dont have any IDLE control it wants to idle at ~500rpm so i need to keep the throttle open a little so it sits at ~850rpm, from here ive tried to tune it (after reading the tuning section in the manual) but adjusting the PWM Current Limit % and PWM threshold seems to do nothing,
and its running rich.

Also if I put the revs to 1800 it fluctuates / pulses and the Lambda Goes from rich to lean to rich (fluctuates).

Im just a little confused with the settings.

Any help would be great,

Ed.

Do you have (or remember) any of the settings still? (i know it does depend on the engine, but it would be a start).

How does the standard ECU work then compared to megasquirt?

I think the pulsing is down to the PWM being too low (well that was what i gathered from the tuning info).

Guess i picked the wrong time to try converting as ill need to car soon, might have to go back to the SU :(

Its just a bog standard 998cc i didnt want to invest any money if it wasnt going to work,
I would like it to be nice and driveable (and reliable), So i guess i could try the standard ECU,

Do you think MS could be piggybacked?

Ed,

First, what firmware are you using and what are your settings. How many squirts per cycle are you using? Is the injector a low impedance one? What's the injector opening time? What's your req. fuel?

You need to have 4 squirts per cycle to have a chance of having a decently running engine and if the injector is not low impedance or the opening time is too big then PWM settings won't do anything useful.

Just give us more information so we can help you.

Jean

http://www.jbperf.com/

I have MS SnS Extra 024s,

I am running 4 squirts as that was the only one i could get it to start with, and yes it is a low impedence injector (the standard one for the 1.3i).

Req_Fuel is 3 or 3.2
Dont know what the opening time is though (oops) guess ill have to find some info on the injector.

Thanks,

Ed.

just checked, Opening time 1.0ms in megasquirt
(i havent ever changed it).

Edited by ed4ran on 3rd Mar, 2006.

Ive finally managed to get a standard ecu, and i was wondering if it needs the flywheel crank sensor? It does do the ignition, but im currently running MS for the ignition,
So i was wondering that if MS doesnt need a crank sensor for injection does the standard ECU???
If no one can say for sure, then i guess i should just try plugging it all in?
Is there any likely hood of damage? or just the engine not running.

Thanks,

Ed. :)

Oh i was thinking that it would need the Tach signal hooking up to where the standard ECU would go to the coil??? Would that work???

Yeah it does have a reluctor ring, but i was wondering if that was just for ignition?
Like MS only needs one for ignition???

Surely the ECU requires a position from the flywheel to allow it to then time the spark correctly, and also to get an engine speed feedback for it to use on the fuelling map?

As far as i was aware you didnt need a crank sensor for MS to do fuel???? just rpm from the coil?

AlexF

Wooo sounds good to me, can I choose my prize, I'd like an Aston Martin Vanquish please, in the absence of one of those, I'll settle for some Cadbury's Buttons.

Ill try hooking it up and seeing if it explodes into tiny pieces.

but doesnt MS use the RPM from the coil to do injection on a standard ignition car?? and only EDIS needing the crank sensor for ignition angle (thus giving MS the rpm)???

The problem i have is that i dont have an SPI flywheel so i cant use the standard stuff and would have to change the flywheel to get it to work, and i dont really feel like pulling the engine out.
So ill need to get MS working well enough to run the car (if the rover ecu needs the flywheel sensor). :(

MEMS needs the crank pos sensor!

Alex

AlexF

I think that the SPi has a 36-2 wheel done in a double 18-1 way. I don't see why you wouldn't be able to use an external wheel with the correct pattern. I don't know how the missing teeth are timed though.

Concerning your MS setup, I think that part of your problem is related to MS-1 resolution which is only 0.1 ms. With a req. fuel in the order of 3 ms, any low load situation will require very short pulses, likely less that 2 ms. With an opening time of 1 ms, that means you have an effective pulse width of less than 1 ms so the 0.1ms precision is 10% or more. It means that you can quite easily go from lean to rich with very small changes of rpm or map or IAT.

One other possibility for the fluctuation could simply be the fact that you have activated the EGO correction. With the correction, MS will try to maintain the target AFR by going leaner or richer and depending on your setup and again due to MS-1 resolution, you can go from quite lean to quite rich.

The best would be to go the MS forum (on the MSnS-e forum) and post your msq and a datalog together with the description of the problem. There are a lot of people there with a lot of tuning experience who will be able to help you even if they haven't dealt with a siamese port engine. And there are others with a and b-series engines.

Jean

http://www.jbperf.com/