dfwrx7

Since upgrading from the original B&G code to the current MSnS-Extra code I've noticed that my fuel pump relay now buzzes, I believe with the ignition input. Here's the kicker. According to the FAQ here and the MSnS-Extra docs I've read, I have everything set up for Fuel Only. No ignition configuration at all. Did pinouts or wiring change in the interim? Granted I've been away from the MegaSquirt community for a while but I don't think the hardware has changed THAT much.

jayroc

You're sure it's not the fuel pump? Sometimes mine will flake out and not turn off like it should.
Do you have the MS relay board setup?

muythaibxr

what version of the board are you using? it sounds like the fast idle and fuel pump pins may have changed if you're not using a 2.2 or v3 board... in msns-extra it is possible to set up the fast-idle pin as an ignition pin...

In "Code Config->Code base and outputs function" make sure all the "code types" are set to "off" and make sure that FIDLE function is set to "Idle Control"

Also, if it's already set to that, then the buzzing could be because the ms is set up for PWM idle...

You might want to ask about this one on msefi as I have no experience with any boards older than 2.2 and don't know if there's any easy way to find out if the pinouts have changed.

Of course the relay or wiring could've also gone bad at the same time you upgraded, but I doubt it

dfwrx7

Quite sure. I do not have the relay board. When I installed this MS, they were just beginning discussion of the relay board. Since then I got married, bought a new car, bought a house and had a kid, all in 2002. I've been somewhat busy keeping on top of life much less keeping up with the Megasquirt community. Now that the kiddo is three and much more self-sufficient I'm allowed a few minutes here and there to work on things like the autocross car.

I heard the buzzing in the cockpit over my straight-through exhaust. I isolated it by feel. I did just find the culprit though. It seems that the Idle Air control code for Fielding PWM is causing my fuel pump relay to buzz. Switching over to B&G On/Off mode cured that problem. Now my question is why this may have been the problem. I really liked how PWM idle air control worked on the older B&G code. It would slowly lower the idle as it came closer to operating temp rather than just shutting it off. With my 9# flywheel this can be a bit of a problem to tune around.

muythaibxr

I just looked at the older B&G settings in megatune for the original megasquirt code, and I don't see a PWM option there... just an on-off temperature. I wasn't talking about the relay board though, I was asking what megasquirt board version you have....

the v2.2 board came out in 2002 so I was thinking maybe if you have one of the older boards, the idle and fuel pump circuits aren't isolated from each other very well, and that may be causing the buzzing.

Of course the pins may have changed or there might be another problem.

dfwrx7

I'd have to look on my laptop but it was a 1.x version of Megatune on a v1.01 board. Sorry, thought I mentioned that earlier. I know I was *thinking* it.

My setup is

GSL-SE 6-port, N/A
Early 2nd gen N/A intake
stock 2nd gen BAC
stock 680cc injectors
RB header

v1.01 board + flyback
latest stable MSnS-Extra firmware and MegaTune

Innovate wideband set for 0V-5V


The reasons I upgraded my MS in the first place was the fact that it was far too easy for me to overrev my engine during competition. Several excursions to 10,000+ caused the rear rotor bearing to slip, spin and walk out. This forced the rotor into the center iron, destroying both. At the suggestion of another local MS'ed autocrosser I looked at the MSnS-Extra feature set and decided I had to have:

a rev limiter!!!
12x12 VE tables (more than one!)
AFR target tables
expansion for timing using a 2nd gen CAS

Nice to have features were:
traction control
launch control
sequential shift lights (have that on my tach already)
autotuning via a modern MegaTune
boost control (eventually)
overboost protection (eventually)

After I learn to weld I'm going to be fabricating a DEI chamber for the 2x50mm Ford TB that a friend gave me. I want to keep the stock upper and lower intake manifold to preserve as much torque as possible. Dyno tuning will tell me if it was worth it or not.

muythaibxr

Hrmm, I'll have to find out if the pinouts changed and what the circuits looked like on that version of the board... then I might be able to tell you how to get rid of the fuel pump buzz when pwm idle is running.