It's much better!!!, was Re: [Diy_efi] About MAP sensing and it's

[Tomas Sokorai Sch.]

Thanks!, I tried your idea, and it really did flatten the signal quite a bit. 
It's still not a pancake, but I'm happy that my valvetrain is not too bad :)

For the comparison, take a look at 
http://www.sokorai.cl/camioneta/IGN_ECU_en.html , at the bottom of the page.

Now, I only made a quick cut 'n paste in my program to try the idea, so now 
the RPM calculation routine is messed up, but that's nothing a couple of 
hours of assembler programming won't cure ;).

What has really got me wondering, is how for example Megasquirt goes away 
using an unsync'ed sampling of the MAP signal. If this really matters in a 
stock camshafted engine, how do the guys with more aggressive cams have any 
idle?
Do all OEM ignitions/injection ECUs sync their sensor readings?

On Monday 12 January 2004 21:18, dunvegan wrote:
> Think about what you're measuring:
> you're measuring the volume of air that is being pumped by 8 different
> pumps sequentially, any difference between them like different valve
> sealing, plenum/intake friction/length, port restrictions, etc. can all
> cause differences between each stroke of the 'BIG' pump, so I would expect
> some jumping at idle.
>
> You should see the signal smooth out at higher rpm's, time/averaging taking
> place, I'd take a look on an oscilliscope sync'd to plug wire # 1 to look
> and see if there is a relationship to the jumping to a cylinder, if there
> is not relationship, then you may have a wear/jerky valve train problem,
> but I suspect you'll see it sync up and show it is the difference from one
> cylinder to another!
>
> Good luck, let us know what you see
>

-- 
Tomas J. Sokorai Sch.
Socio director, Gerente Proyectos Especiales
Xperts Ltda. F: 63 244591, Valdivia, Chile
_______________________________________________
diy_efi mailing list
diy_efi at diy-efi.org
http://lists.diy-efi.org/mailman/listinfo/diy_efi