Help with PWm idle valve.

[jagdude]

Hi,

The car is as follows;

1982 Jaguar xj6 (Euro Spec)
MS II code 2.890 V3.0 board
GM Coolant sensor
GM Intake Air Sensor
GM MAP sensor (1 bar)
Volvo 2-wire PWM Idle valve
Ford VR Sensor with EDIS 6
Using existing relays for fuel etc.

I finished installing the Volvo PWM IAC today. Prior to that the car ran reasonably well (just a bit rich).

Power to the IAC is taken off the fuel pump relay and I believe that the IAC is wired up correctly.

When I first tied starting the car it worked with an idle around 1600. My IAC seems to be the type that needs decreasing pwm% as the coolant heats up. I changed various IAC settings in an effort to bring the idle down. Eventually I got it to idle at around 850.

The second time I turned the ignition on the Tunerstudio gauges were displayed normally except for the TPS which pegged at 132%. The IAT and CLT also just flickered from 170 degrees to 100 degrees every few seconds. I opened the MS box to check that I hadn't wired anything wrong and I also tested the 1N4001 diode that's across the IAC power line and the line to pin 30 on the MS box. It tested OK.

For no reason that I can see everything started working OK so I went to take it for a drive.

I started logging after the car was running and set out. I had only travelled about 800 yards when the IAT and CLT gauges suddenly started flicking between 100 and 170 and the TPS pegged again at 132%. I turned around and limped the car back.

I'm attaching the log and MSQ in the hopes that someone can help. I would really appreciate any help.


Jim

[jagdude]

Hi,

I'm trying to use a Volvo two-wire idle valve to control my idle. Can anyone tell me exactly which settings in TunerStudion control the PWM valve and which ones I can ignore? The documentation isn't clear about what applies to stepper motors valves and which are for PWm valves.

There's a pic of the valve type attached for information.

Also, is there a correct way and awrong way to connect to these or does it not matter???


Thanks,

Jim

volvo-pwm valve.jpg

[schnitzer318is]

Having been going through this same arduous process over the last few days. I believe the volvo valve is a bosch 2 wire PWM. I found an old thread about them somewhere on this forum which helped me out immensely. My BMW uses a slightly different valve, but is also the same 2 wire bosch variety so hopefully this will help you out too...

Keep in mind... I'm not even sure these values are correct for my car/valve (except for the frequency and closed settings). But they are the best I've come up with so far. Hopefully it will give you a jumping off point.

[jagdude]

Thanks schnitzer318is. I'm still trying to establish solid numbers for it. When I achieve something I'm happy with, I'll let you know.

[jagdude]

schnitzer318is,
Does it matter what direction the air flowes through the IAC??

Thanks

[schnitzer318is]

schnitzer318is,
Does it matter what direction the air flowes through the IAC??

Thanks

I thought so... mine has an arrow anyway. But upon thinking about it... it's just a valve that opens and closes so either way you get the same effect. If there is no arrow on your unit I wouldn't think it would matter. Maybe someone else will chime in.