I'm not crazy about the PWM closed-loop idle control in MS... it just doesn't seem to work as consistently and smoothly as the stock ECU.

From what I can tell, the oem ecu looks at the heater, A/C, and headlight inputs and adjusts the idle accordingly. I don't think it would be too hard to modify the MS code to do this. It would just require wiring in these inputs, and having the MS code adjust the idleDC (warmup mode) when these inputs are switched on. I should be able to handle the code changes myself.

Any foreseeable issues?

Discuss!

 

wait until keith has finished the PID control loop for closed loop idle?

That should make idle far better at coping with changes.

I'm testing an early version with just P and I and it's far better already!

 

Justin, I totally agree... I brought this up in the A/C FAQ thread, but it seems like most folks shy away from touching the MS code (maybe with good reason). I don't think the PID control loop alone will be enough since it will still have to react to a drop in idle rather than preempting the drop by reacting to the actual accessory coming on. An alternative solution might also be to use an ammeter to measure alternator current added to an additional "A/C is on" signal to drive a vacuum leak valve of some kind.

 

once suggested solution was triggering the purge valve solenoid to open with the A/C

 

Holy, I think you're right, but I'll probably wait until the PID code is released before I make any changes. If the PID loop works well enough, then I won't bother. But if I'm still not happy then I'll do it.

 

Yeah, I actually have my car setup to do this on your suggestion. The purge valve alone doesn't create enough of a vacuum leak to fully cover up the idle dip. I think a bigger valve is needed. Of course, and adjustable valve would be awesome... however, at the end of the day we're just reinventing the idle air valve which already has computer control

Is there a thread about Keith's plans/progress somewhere?

 

The only thread I know of is this one: MSx/Extra EFI • Login

 

Incorrect. A/C, brakes, gearbox (neutral switch), clutch switch, steering switch, yes. Heater, headlights, power windows, other electrical loads, no.

Jim

 

What about the blower control switch? I see there is an input to the ecu that goes low when the switch is at mid or high positions.

How sure are you that it doesn't adjust idle when the headlights are switched on? I see there is an input to the ecu for the headlight switch.