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megasquirt advice please
omega0684 - 5/10/08 at 04:09 PM

afternoon all,

just been out playing with megalog viewer and meagsquirt, went for a short drive for about 10 minutes but only round local streets so didn't go more than 25-30 mph, after my analysis the viewer told me i need to lower the values around idle so i did.

now heres the thing, as i adjusted them to the lower values it suggested my idle went up but my AFR got much better, my car now idles at about 1300-1400 rpm, whereas before it was about 1000 but my AFR has gone from 12:1 to about 14.3/14.4:1

the AFR is great now that its in the right area but how do i get my idle down to 900-1000 again

please help


rusty nuts - 5/10/08 at 04:27 PM

The reason the idle has risen is because the engine is now running more efficiently . One way of tuning carbs was to adjust the mixture until the best idle speed was obtained


omega0684 - 5/10/08 at 04:54 PM

robocog what tb's and engine are you running


omega0684 - 5/10/08 at 05:18 PM

yours sound like they are the same as mine, 2002/03 ITB's do yours have orange injector casing? i know the idle adjuster you are talking about but mine is fully off so the butterfly's are as closed as they can be, what about the individual screws on each TB, would closing those help with the idle?


omega0684 - 5/10/08 at 05:44 PM

where else could there be an air leak apart from the vac pipes, could this be the reason my MS is reading my kpa value as 97


omega0684 - 5/10/08 at 07:18 PM

at moment im using alpha-n to tune as i dont know where the leak is, not using map sensor


blakep82 - 5/10/08 at 07:27 PM

sorry to hijack slightly, is what is megalog? by the sounds of things it can give you pointers to set up the ignition, can it be used with megajolt too?


Lars - 5/10/08 at 07:28 PM

I also have these TBs, and I thought that I had the butterflies shut as much as possible on the cable, but it turned out that the spring was just a bit stiff/stuck.
I unscrewed it further and then pushed the butterflies gently against the stop.
That freed it up and it now returns to that spot.

Mine idles at about 1300 at the moment, but I can screw it back alot further. THe problem I have is that the idle increases as the car warms up, and it currently idles at 800 when cold.


omega0684 - 5/10/08 at 08:00 PM

blakep82: megalog viewer is a program that allows you to visually see what is going on in the engine after you datalogg the car for a period of time, it logs all sorts of data, rpm, map, throttle position, AFR, timing advance, spark angle, all sorts, its an awesome bit of kit once you know how to use it (im still learning)

im not sure that it can be used with megajolt, my thinking would be no as i think that its designed in conjunction with megasquirt ecu's

as for everyone else, could someone please suggest where i might be getting an air leak from, i have tried vac hoses, the connection at the ecu, the hoses that connect the manifold to the TB's i just cant find one or ive missed the obvious!


Jenko - 6/10/08 at 03:05 PM

After fitting I noticed that the springs on the butterflies are not really designed to support a weighty throttle pedal - I found the butterflies would not close all the way.

I overcame this by adding a throttle return spring.

There are only limited places where air could be leaking...Do you have balancer for the TB's...this may shouw you which cylinder is the worse offender.


paulf - 6/10/08 at 03:16 PM

No its for megasquirt only but megajolt also has a dataloging option but it only shows advance ,throttle position or vacuum and revs but may help when driving and noting revs and load at cruising speed etc.
Paul.

quote:
Originally posted by blakep82
sorry to hijack slightly, is what is megalog? by the sounds of things it can give you pointers to set up the ignition, can it be used with megajolt too?


paulf - 6/10/08 at 03:25 PM

Have you checked the idle bypass screws ? if I remember correctly the R1s may have a bypass system for fast idle when cold this lets air around the butterflys they may also have some adjuster screws for balancing the bypass air as well as the throttle linkage adjust ment.
I would start by slackening off the throttle cable and adjusting all the butterflys to be fully shut then open them until you can just see a gap on them all.Start the engine andadjust the balance again from here and get the tickover smooth, then fit and adjust the throttle cable .
The idle vacuum should be about 40 to 50 kpa when warmed up and throttles balanced.
Paul.

quote:
Originally posted by omega0684
as for everyone else, could someone please suggest where i might be getting an air leak from, i have tried vac hoses, the connection at the ecu, the hoses that connect the manifold to the TB's i just cant find one or ive missed the obvious!


Jenko - 7/10/08 at 02:59 PM

quote:
Originally posted by Scoobylav
I may be wrong but I am sure I read when we were setting ours up that when you are using TB's you had to use Alpha N as the Kpa value will never be correct as the TB's never create enough vacuum and therefore give a false reading.


I have also read this, but I know of a few people who had success with MAP....I too used the TPS and alpha N, and have not had any problems.....