90 with MSPNP
Do your MSquirted Miatas idle fine?
I cant get mine to idle correctly, the rpms oscillate from 900-1200 all the time. I tried "closed loop" and "warm up only" and cant get it to idle like a normal car.
I dont think it's anything mechanical because it idled fine before the MS. (It's a PNP)
Also, my WB keeps jumping between 12-15 when driving normal just cruising. I tried different grounds and free air calibrated it (yes, outside the downpipe) and it wont read steadilly.
Please help me, I'm getting frustrated, it's been a long time...

 

if you pull the plug on the idle valve does it react the same?

WB reading is all in the tune.

 

I'm going to try that.

I dont think the WB issue is all because of my tune. I go in the highway at steady speed (map not moving) nothing moving, rpms steady but the WB wont stop jumping from 12-15.

 

i pulled the plug and it does the same. This is worst when the car it's cold, it goes from 600-1200 when cold.

 

Check the wiring on the WB?

 

do you have acceleration enrichment enabled? I had an issue with the fluctuations in the MAP reading setting this off. Check the bottom right gauge on your realtime VE tuning page and it shows an enrichment gauge.

 

Richen up your idle some. You can only idle them so lean. If you add fuel it will stabilize without oscillating. Atleast until your IAT heatsoaks, but that is another issue.
Add 1 point VE to all six idle cells like you can see here. Using the arrow cursor highlight all 6 cells. Enter the value you want in the top right and push the = button. Add one point at a time till it smoothes out.

Post your msq otherwise.

 

I fitted a PNP on my 90 and the area I have had most issues with (and I am just really starting to sort them now) is in idle and low speed light throttle stuff. I have now gone to Hi Res code (big improvement), fitted an auto TPS and am fiddling with the relationship between the idle control valve, idle screw and the spark and VE values in the idle regions... I now get a steady idle of about 1050rpm and am turning the idle screw out a little each day to bring this down.

With the wavering AFR's check that the MAP signal isn't the cause. At the weekend I moved my MAP signal tube off the takeoff near the throttle body to one at the rear. My datalogs now show a much smoother MAP signal and the AFRs don't waver.

My cold start and AE are still pretty $hit though... that's the next job.

 

I richened the VE table on idle and it now idles decent, only fluctuating about 100 rpms.
ABOUT THE WB: I tapped the back of the intake mani and I use that fitting for the MS, so that's not the problem. I just got done rewiring the whole wideband, it was already fine (soldered and heat shrinked) but I relocated it and made it look neater. Still fluctuates from 12-16 all the time, even at idle.
I did a free air calibration, is there any other kind of calibration I should do?

 

Yep.. I have to run pig rich at idle to keep it from oscillating. Down around 10.5:1 on the wideband.