Duty Cycle
 

how do i up my duty cycle? mine is reading at 1.9 to 2.0 percent...what is it suppose to be at...?mspnp

I assume you're talking about injector duty cycle. Your "1.9 to2.0%" sounds like at idle. Want to increase it? Drive.

Yes more boost+rpms=higher DC :rofl: duh comeon man

mine idles at 1.7 DC with the same injectors, nowt you can do about it bar installing smaller injectors.

I presume you want the DC to be higher to have a better Idle? unfortunately you SOL mate.

my car keeps shaking like crap at idle...i can't even drive it after i put in the mspnp i read the manual but crap...i can't get this thing going so i'm just asking some radom questions LOL....i am running 550cc high impedance injectors and 255 walbro fuel pump...i'm getting like a 18.? at air fuel ratio.... i think thats suppose to be really lean... what can i do to make my car at least driveable to the dyno so i dont get ripp the heck off...

so increase the VE fuel table a bit. did you redo the req_fuel number?

it's not going to work straight out the box for you.

alright...i'll try messing with the VE table...and yeah....i did do the require fuel....i think it was in the engine constant where i have to enter my engine displacement...and injectors size...

come on everyone. While driving may be a way to raise your duty cycle, all the cool kids just put smaller injectors in instead.

okay...now my car wont start...LOL...i'm done..taking it to someone else...

reload base map. set constants. try again.

unplug ignitors when flashing

and uh RTFM

The MSPNP has opened the doors of incompetency, atleast before when people had to do something besides hook up a few connectors they understood that reading and comprehension was an important part of standalone engine management. If they didn't understand that they couldn't complete the project.
RTFM FTW

Question about this. Something the manual doesnt make very clear.

The first time you flash it with firmware you have to unplug the ignitors, but.... when you just change VE tables and its internal settings, do you still have to unplug the ignitors or can you do it on the fly?

NO. only for flashing firmware. you can make any other changes while doing 80 down a side street in a school zone

Sweeeeeeeeeeeeeeet.

Well im gonna do the initial flash on my table using a stim anyway.

I've flashed entire MSQs while idling in a parking lot. Just unplug when you flash firmware, and LEAVE THEM UNPLUGGED until you get a good MSQ in.

:werd:

The Megasquirt is based on pulse width, not duty cycle. Increasing the pulse width, of course, increases duty cycle. Some basics on how it works:

1. The Req_Fuel number is best described as your base pulse width. Adjust it to move your entire pulse width up or down.

2. The Megasquirt then calculates the air density from the MAP and IAT sensor readings.

3. Then it multiplies the pulse width from step 2 by the percent in the VE table.

4. It applies anything from correction tables, like acceleration enrichment.

5. Finally, it adds on the injector opening time to the pulse width.

It sounds like what you need is a higher VE setting at idle.

You can do this stuff, but you have to read the manual. Sit down one day, away from the car, and read the manual cover to cover. You might have to read it again, later, to apply some of the concepts and rationalize others. You might want to buy a book on tuning FI. I believe Matt Cramer told me the title of a good one on the phone, which I don't remember, but now wish I had so I wouldn't look like an irresponsible asshole, calling the kettle black when I'm a dark shade of gray.

I expect to have a ton of stupid problems that will get me banned from this forum, but I will be certain to read the manuals (again) first.

yeah, i gotta second (third? fourth? millionth?) the recommendation to really put some learning in on this. i know you just wanna get the car running right now, but take a day and learn how it's working, then you can fix these problems yourself.