DIY PNP Megasquirt, MicroSquirt BG 2.890 code.
Hi
The problem I have is noise (I think) from my PWM idle valve (2 wires)
With the ignition switched on the Tps and coolant temp gauges on megatune jump around with air idle plugged in. As soon as I disconnect it they stop.
I have the flyback diode in place and have even replaced it and tried another at the idle plug with no joy.
Any ideas Ferd
Noise from PWM idle valve
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0).
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
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Matt Cramer
- Super Squirter
- Posts: 2951
- Joined: Sat Jul 03, 2004 11:35 am
Re: Noise from PWM idle valve
What sort of PWM IAC valve is this, and what frequency are you trying to run it at?
Re: Noise from PWM idle valve
Hi
It’s a Ford iac valve as used on the Zetec and its set at 80Hz in the idle control.
I was having trouble getting the car to idle and tried adjusting it but this did not work.
I found out it was the 10 steps of the PWM idle dutycycle my car will not idle at 100 but is ok at 80.
Could I have damaged the Pwm transistor?
Ferd
It’s a Ford iac valve as used on the Zetec and its set at 80Hz in the idle control.
I was having trouble getting the car to idle and tried adjusting it but this did not work.
I found out it was the 10 steps of the PWM idle dutycycle my car will not idle at 100 but is ok at 80.
Could I have damaged the Pwm transistor?
Ferd
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Matt Cramer
- Super Squirter
- Posts: 2951
- Joined: Sat Jul 03, 2004 11:35 am
Re: Noise from PWM idle valve
Most Ford valves we've seen run at more like 300 Hz. I think 320 is the closest value you're allowed to enter.
Re: Noise from PWM idle valve
Hi
Tried setting the idle control frequency to 320Hz and it’s still the same and I also tried another IAC and it’s still the same.
Can I just clarify the PWM idle connection on the DIY PNP with you to make sure I have them right?
I have the flyback diode in R5 one leg in the left hole and the right leg in the 5v hole. Is this right or dose it go in the 12v next to it?
I have the output for the idle in the IAC hole just under the proto area next to Tech-out.
Other than that I am at a bit of a loss.
Ferd
Tried setting the idle control frequency to 320Hz and it’s still the same and I also tried another IAC and it’s still the same.
Can I just clarify the PWM idle connection on the DIY PNP with you to make sure I have them right?
I have the flyback diode in R5 one leg in the left hole and the right leg in the 5v hole. Is this right or dose it go in the 12v next to it?
I have the output for the idle in the IAC hole just under the proto area next to Tech-out.
Other than that I am at a bit of a loss.
Ferd
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Matt Cramer
- Super Squirter
- Posts: 2951
- Joined: Sat Jul 03, 2004 11:35 am
Re: Noise from PWM idle valve
You should have the banded end going to 12 volts, not 5 volts. You'll probably have electrical noise issues if you wire it to 5 volts, at the very least.
Re: Noise from PWM idle valve
Hi Matt
I have just changed the diode and put it in the 12v hole as I did have it in the wrong hole.
I may have had a 1k resistor in R3 wrong as well as I am using the Edits unit.
Any way it’s really good news as after I generate an idle dutycycle curve 0 to 80 she started and runs really well and idles and the gauges have stopped moving.
Matt you’re a star thank you ever much for your help I am sure I will be back.
Ferd
I have just changed the diode and put it in the 12v hole as I did have it in the wrong hole.
I may have had a 1k resistor in R3 wrong as well as I am using the Edits unit.
Any way it’s really good news as after I generate an idle dutycycle curve 0 to 80 she started and runs really well and idles and the gauges have stopped moving.
Matt you’re a star thank you ever much for your help I am sure I will be back.
Ferd