5 replies to this topic

[Wazzah]

I am after information regarding the MPI flywheel, its missing teeth and the crank angle sensor offset.

I am currently fitting an aftermarket ecu to my 99 JDM SPI Mini.

This year model uses an MPI block with the 36-4 flywheel trigger.

The ecu software has the MGF trigger system which I believe is the correct 36-4.

That MGF trigger is set at a 70 degree offset as a default.

It simply wont start on this setting.

It will fire but the ignition event is way too early as the engine struggles to turn over.

I was using static ignition advance of 10 degrees BTDC.

Retarding advance to 6 degrees didn't help.

Adjusting this offset seems to be the answer given this is the only other variable.

I believe the 36-4 pattern has it's first missing tooth at 30 degrees and it wont fire at a 30 degree trigger offset.

Increasing the offset gradually hasn't helped.

I have a MEMS document (attached) that states the first missing tooth is at 80 degrees and that the crank sensor itself is 55 degrees offset from top dead centre.

I can get it to run at a fast idle at of 1200 rpm with an 85 degree offset in the software but am worried about knock.

The ECU supplier (Haltech) has no information that assists me.

Do any members have better information that I can get my head around?

Attached Files

•  mems3.crank.and.cam.pdf   603.85K   9 downloads

[genpop]

Hi Wazzah,

accordig to your pdf, the CMP has to be on the right position too.

[Steve220]

I am after information regarding the MPI flywheel, its missing teeth and the crank angle sensor offset.

I am currently fitting an aftermarket ecu to my 99 JDM SPI Mini.

This year model uses an MPI block with the 36-4 flywheel trigger.

The ecu software has the MGF trigger system which I believe is the correct 36-4.

That MGF trigger is set at a 70 degree offset as a default.

It simply wont start on this setting.

It will fire but the ignition event is way too early as the engine struggles to turn over.

I was using static ignition advance of 10 degrees BTDC.

Retarding advance to 6 degrees didn't help.

Adjusting this offset seems to be the answer given this is the only other variable.

I believe the 36-4 pattern has it's first missing tooth at 30 degrees and it wont fire at a 30 degree trigger offset.

Increasing the offset gradually hasn't helped.

I have a MEMS document (attached) that states the first missing tooth is at 80 degrees and that the crank sensor itself is 55 degrees offset from top dead centre.

I can get it to run at a fast idle at of 1200 rpm with an 85 degree offset in the software but am worried about knock.

The ECU supplier (Haltech) has no information that assists me.

Do any members have better information that I can get my head around?

Wazzah, speak to Haltech Australia. They still have the map from Moog's car which was the same base engine as yours.

 

Are you using a light gun to set the timing?

Edited by Steve220, 03 October 2021 - 07:04 AM.

[Bobbins]

A '99 JDM is fundamentally an MPi bottom end and flywheel with the older SPi injection, ignition timing is therefore the same as for an MPi, it is only the injector firing that needs to be different, although I'm sure you're aware of this!

However, although the MGF flywheel has a 36-4 flywheel pattern it's a K-Series. Are you sure missing teeth the pattern is the same for both? Even if you allow for a different offset for the location of the crank position sensor a variation in the pattern of the Mpi flywheel and the pattern the ecu is expecting to read would cause major issues. Definitely worth double checking.

[FlyingScot]

Think this might help… https://www.theminif...i-ignition-out/

 

Also I’m presuming it’s the same clutch as before…

 

FS

[Steve220]

Just to bring this back up after a similar issue - Remember the pre-set for the 36-4 K series flywheel is based on just that - the K series! The A series MPi has the same flywheel, however the sensor is in a different location, and therefore the offset is very different. Each ecu manufacturer may also have a different placement on the flywheel where it classes TDC, so the only true way to find it is with a strobe and changing the offset 10 degrees at a time to bring it into sight, then adjust it a few degrees at a time to bring it into true.