idle problems, is it my setup?
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Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
idle problems, is it my setup?
I find it very hard to tune my idle, I cannot get it stable and strong. Please have a look,am I doing something wrong here?
MS1, MT2.25, extra code q2
http://kmnet.demon.co.uk/~arnold/
http://kmnet.demon.co.uk/~arnold/
it runs oka, sometimes a small hesitation, but that is not worrying me. I am afraid I need idle air control, which would rather not have as I run MS1 stock code
MS1, MT2.25, extra code q2
http://kmnet.demon.co.uk/~arnold/
http://kmnet.demon.co.uk/~arnold/
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jharvey
- MegaSquirt Newbie
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My guess would be that the injectors are over-sized for the idle. Your pushing a fair amount of HP out of the injectors and demanding a large flow variation.
Hmm at idle your probably running a fairly low duty cycle, it's possible that the injectors are running at the threshold of their lower limit. If the injectors take 4ms to open and your running 4.5ms at idle then your really only running .5ms of injection. If the tolerance is +/- .1ms (8 bits for 255 or 25.5ms) then your going to see quite a fluctuation at idle. Do you know how much lag you get from the injectors? If this is the case I'm not certain the idle bypass would help.
When your running idle / wide open what is the minimum / maximum your injectors PWM gauge goes to? You can check the log for this. If you are less then 21.5ms or 85% duty, then you might be able to decrease the size of your injectors and increase the PWM at idle. I don't believe the 85% is a cut in stone figure, if your at 90% you can probably still decrease the injector size.
Another possible idea is to use two injectors/cyl one with low lag time and low flow rate and another with a long lag and hi flow rate. That way when you approach idle the large injector simple stops squirting. It's a hack I know but a possible alternative.
Hmm at idle your probably running a fairly low duty cycle, it's possible that the injectors are running at the threshold of their lower limit. If the injectors take 4ms to open and your running 4.5ms at idle then your really only running .5ms of injection. If the tolerance is +/- .1ms (8 bits for 255 or 25.5ms) then your going to see quite a fluctuation at idle. Do you know how much lag you get from the injectors? If this is the case I'm not certain the idle bypass would help.
When your running idle / wide open what is the minimum / maximum your injectors PWM gauge goes to? You can check the log for this. If you are less then 21.5ms or 85% duty, then you might be able to decrease the size of your injectors and increase the PWM at idle. I don't believe the 85% is a cut in stone figure, if your at 90% you can probably still decrease the injector size.
Another possible idea is to use two injectors/cyl one with low lag time and low flow rate and another with a long lag and hi flow rate. That way when you approach idle the large injector simple stops squirting. It's a hack I know but a possible alternative.