MS1 Pwm Idle does not work.

[Keithg]

WHich transistor are you using to drive the AIC?

KeithG


Posted by email.

[superchargingmachine]

KeithG,

How can I get a copy of the un-compiled code?

[fred_bx16s]

hello

i working in my settings and avlues is ok for idle rpm hot engine but is no good for idle cool

cranking 87
min 86
closed 85


tps adc 30
dashpot settle 150
dashpot adc 3

thanks

[RickyJ]

Keith, I'm using the ZTX651 transistor and 510 ohm resistor. After I replaced the parts, I checked for conductivity between the freshly soldered legs and the next closest connected components.

I added the idleDCGauge to the dashboard. From cold, it counts from 0-255%DC 5+ times before it settles at 80% at 1200rpm (where it should be). I changed the adder to 300rpm as well. Varying the idle speed with the idle screw still does not make the valve move.

[Keithg]

closed should be much lower than 85 for this to work.. also your min to cranking needs to be greater. there is no room to regulate anything if it only has 3 DC % points to operate in.

Crank should be enough to allow the engine to catch at approx 2000 rpm and decay to idle speed.
Closed is the value at which it is closed and no (or very little )air can pass through the device.
Min is 3 to 5 percentage less than the lowest observed regulated idle DC% value (when it is regulating).

IIRC, your valve needs 25% as closed. If you are running idlefreq as 200, it should be 50.
Cranking should be 50% (or 100 if your idlefreq is 200)
you will need to adjust the throttle stop to close it a bit to make sure that teh AIC has some 'room' to work.

KeithG

cranking 87
min 86
closed 85


tps adc 30
dashpot settle 150
dashpot adc 3

Posted by email.

[Keithg]

the uncompiled code is in the msms-extra.asm file in teh src directory.

KeithG

On 8/22/06, superchargingmachine < superchargingmachine@yahoo.com (superchargingmachine@yahoo.com)> wrote:

KeithG,

How can I get a copy of the un-compiled code?

Posted by email.

[Keithg]

Slow down your slow recovery (try 40 or 50 here). You may just be closing too fast for the algorithm to regulate at first.

Speed up your closure speed (try 5 or 10 here). The closure speed is how fast the valve closes when the throttle is above the threshold. If it is 0 it steps closed at 1 step per loop ( 0.1S per loop). If it is 5 it is 0.6s per loop...

KeithG

I added the idleDCGauge to the dashboard. From cold, it counts from 0-255%DC 5+ times before it settles at 80% at 1200rpm (where it should be). I changed the adder to 300rpm as well. Varying the idle speed with the idle screw still does not make the valve move.

Posted by email.

[RickyJ]

Still no action from the valve. I can blow through the valve when the engine's idling, so it doesn't seem to be receiving ground at all. The transistor did go to board ground though, so I'm pretty confused.

[RickyJ]

Decided to check the ECU again, and found that the base and collector of the ZTX651 were shorted internally, possibly from current transients when I first started it up. Replaced it with a TIP122, and it's running!! I had to drop the frequency to 100 and drop the minDC to 25% (same as closed) for it to idle at the proper speed, even with the idle screw turned all the way closed. It hunts a bit, less now that I've increased the deadband to 50rpm from 30rpm, going to increase it more later.

I guess that means I have to replace the ZTX651 with a TIP122 in the ECU for my friend. At least I know it works!

[Keithg]

good work!

If closed is min, then you need to close your throttle plate a bit more so that min is closer to 40%. You really want the AIC to operate where its flow is more linear than right around closed. That is one reason it may hunt.

KeithG


Posted by email.

[snillet]

hello

i working in my settings and avlues is ok for idle rpm hot engine but is no good for idle cool

cranking 87
min 86
closed 85


tps adc 30
dashpot settle 150
dashpot adc 3

thanks

These engines are extremely sensitive to idle advance settings. You really need a well tuned advance table to get the pwm closed loop idle to start working.

I think this goes for a lot of other engine types also... but i know the Peugeot/Citroen 16 valve engines is a bit "bitchy" around idle with the settings.

[superchargingmachine]

Keithg,

Did you ever get that write up from me? I sent it as a zip file so I hope it didn't get blocked. I tried to write up directions based on what I have learned setting up PWM. I can resend it a different way if you didn't get it.

I finally have a set of settings that work almost perfectly. In 2 weeks of daily driving. I have only had one start up where the RPM hunted a bit for maybe 20-30seconds then settled.

BTW - The suggestion to close the TB to get the valve to open more and run it a more linear part of the curve makes perfect sense. But, never occurred to me before. I may experiment a bit with this just to see what happens. My idle dc is 8-13 dc depending on IAT, which seems pretty low.

[fred_bx16s]

hello

my pwm idle is ok only if activate narowband corection
i think my map ignition is no corect but my map ve is very bad lol

thanks for all help

[RickyJ]

good work!

If closed is min, then you need to close your throttle plate a bit more so that min is closer to 40%. You really want the AIC to operate where its flow is more linear than right around closed. That is one reason it may hunt.

KeithG


Posted by email.

That's the problem, I can't close the throttle any more. The linkage stop allows the plates to fully close, and the idle bypass valve is fully closed. I think I have to go digging to see if there's any vacuum leaks, though there's hardly anything on my manifold. My engine is a modified earlier version of the engine that the valve came from, so it should definately be working in the 40%dc region.