MS3 idle droop/stall help
 

2000 model rev built MS3 basic. I can't seem to get rid of this idle dip/stall. I included a copy of my current tune and a log with a large droop at the end. Any help or suggestions would be appreciated.

Nothing but crickets......

Well, you posted (2) tunes and no logs. But I will post up my msq which goes into idle 99,9% of the time, and is barely noticeable when it does miss. I will give some hints below, and then you can see what I have. I'm not saying it's perfect, but the delays and values that relate to your issue, fixed that issue for me.

1) After fully warmed up, with idle valve closed (if you don't know how to make that happen, then you are at square zero), and adjust the screw on the throttle body until idle is 100 RPM below your target. This should prevent stalls.
Oh, 0) establish and set your min and max control PWM's.
2) I use target idle PWM, not remember last one. These numbers are not just targets. The dashpot gets added to these, so they are important. These numbers, plus dashpot, plus fan adder (when fan is on), plus A/C adder (when A/C is on) all set the idle valve so that RPM's settle above your target RPM, then Closed Loop has a chance to take control.
3) Use a delay before going into CL, else you will sometimes go into CL at a high RPM and then the PID will drive the valve closed.

DNM_Tune

Fixed my original atachments. Added the log I thought was there too begin with.

Thanks for the tips. I'm going to tinker with it on my day off.

I have messed with this thing for the last few days and I can't make any progress. I checked my min. and max idle valve settings. I made sure the idle screw was set about 100 rpm under my target idle rpm. I tried delaying CL idle and no delay. I turned over-rev off and tweaked the settings with it on. Regardless of what I have tried every time I take the car out it stalls at least once from just pushing in the clutch and coming to a stop. I am really irritated with this thing right now.

See:
pwm-idle-up-no-reason

This includes info and pics of all my idle settings that address not only the OP's first question, but yours as well.

*EDIT* Did you set the idle valve to closed position when you set the screw? If your are warmed up, then the car should not go below your idle screw set-point UNLESS, there are other loads present that were not there when you set the screw, and your Idle Valve settings are not accounting for them (fan, A/C) or cannot account for(other electrical loads, power steering).

Otherwise concentrate on having sufficient dashpot.

If the above does not help, post back and I'll take some time to look at your msq (post up the latest msq, please) and logs.

Tried tinkering with the car some this morning. Now the fuel pump won't run. Turn the key on and get no priming pulse, car cranks but won't even try to start. I guess maybe the pump went out while I was tinkering..

If you set all of the Priming Pulses to zero, then the pump will not go through the priming cycle. May or may not relate to your issue.

My offer to look at your latest msq still stands, regarding the missed idle / stall situation. However, it may be Tuesday night before I can give it good attention because my family is here for the holidays.

It seems to me that you are changing things without a concept or theory of why you change what you change. So many areas over-lap, so a change that "works" to fix a problem, may cause a problem somewhere else.

As a for-instance of some things that interact: since, during after-start, ASE and WUE are both active and additive, if you change WUE at a temperature, you may need to also compensate by a counter-change in ASE at that temperature for after-start to keep the same fueling.

On other threads, you were having fuel or spark issues at other than idle also. I hope it goes well.

I don't mind admitting that I am far from an expert. My fuel pump went south, I hadn't touched my priming pulse table. I tried my oem ecu and the pump still wouldn't prime. So I replaced the pump and the car has other problems, the ecu is cutting out under load. Looking at a log the car will suddenly go lean then the TPS and MAP drop to 0 for a short time before jumping right back up to full throttle. So who knows. Maybe it's time to give up on the MS3. Thanks for the offer of looking at my tune. If I can get this issue worked out I will take you up on that.

does it always stall?

you have to look closely at the logs and see why.

Is it because you don't have any fuel injecting when you should be coming to idle off overrun, or is it becuase you cant tune and dont open the idle valve enough?