Ford PWM Idle valve settings in Megatune

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cwdman
MegaSquirt Newbie
Posts: 4
Joined: Wed Dec 09, 2009 8:29 pm

Ford PWM Idle valve settings in Megatune

Post by cwdman »

I have successfully installed MS-II with 2.8 code version on my Ford 302 engine. I've been running for 6 months now with no problems even have my MSD ignition MS controlled. The last obstacle I need to resolve is using the Ford PWM idle valve for cold start operations since easy starting is one of the reason I switched to EFI. I installed the kit supplied by DIYAutoTune for Ford PWM and have the wiring installed with 12v in the run position at the valve, the other wire goes to pin 30. I cannot seem to find the settings anywhere for Megatune to set the control parameters. I have selected the algorithm in both Megatune and the configurator, but need to get the following information:

PWM Frequency (Hz)
Start Value (retract)
Cranking Position (extend)(steps)
Crank-to-Run Taper Time (Sec)
Hysteresis (F)
Cold Temperature (F)
Cold Position (steps)
cold Taper Time (sec)

I've tried a few things I have read, but cannot seem to get the valve to work. Is there someone out there who has been able to get the PWM idle valve to work? Any information would be appreciated.
Matt Cramer
Super Squirter
Posts: 2951
Joined: Sat Jul 03, 2004 11:35 am

Re: Ford PWM Idle valve settings in Megatune

Post by Matt Cramer »

They run best at a frequency of around 300-320 Hz. They're closed at zero duty cycle, and close to fully open at 50%. That isn't a complete set of settings, but it should be enough to get you started.
MegaScott

Re: Ford PWM Idle valve settings in Megatune

Post by MegaScott »

Matt Cramer wrote:They run best at a frequency of around 300-320 Hz. They're closed at zero duty cycle, and close to fully open at 50%. That isn't a complete set of settings, but it should be enough to get you started.
I use the idle valve test function to characterize the valve, since the pwm settings are dependent on
the engine and the year... the valve frequency is pretty much personal preference, if it's too low you get noisy sluggish performance, too high and it doesn't work at all. try for something in between. Experiment with the car warmed up, then use those settings cold, and adjust the table to keep a constant RPM while warming up.
cwdman
MegaSquirt Newbie
Posts: 4
Joined: Wed Dec 09, 2009 8:29 pm

Re: Ford PWM Idle valve settings in Megatune

Post by cwdman »

Its been a while since this last post of mine, but I have not yet solved my problem of getting the PWM idle valve to work. I've been living without a warm-up option while completing different projects, but now its time to revisit the PWM idle problem because EFI is not 100% complete until I can warm-up without nursing the throttle.

The external wiring is 100% correct I am able to make the valve open and close by by-passing the megasquirt and manually ground the wire going to pin 30. The megasquirt disconnected completely and the engine not running just the key on. The wires going to the valve its self, one is 12v key and run position with diode installed between the two wires banded end towards the positive. The other wire goes directly to pin 30 on the DB37 connector.

The internal circuit seems to be alright. With my mulitmeter and the circuit diagram I've followed each leg coming from the TIP 120 transistor which is mounted on the heat sink with a insulator and grease.
One goes to body ground just like the diagram with a jumper in R39 spot.
One goes to pin 30 and D8 is not installed.
The last one goes to R19 and then to daughter card and Q20 is not installed.
There are no signs of burned components or bad solder connections.

As for the software I've tried just about everything in both the idle setting and pwm duty cycle and cannot get the valve to even move once. I've set the configurator to PWM valve and the idle setting in megatune to PWM warm-up.

Not sure where to begin trouble shooting now, I would appreciate any help to test the circuit further and if anyone has a Ford PWM idle valve working to let me know the settings.

Thanks
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