MicroSquirt.com read only forum (Jan.15,2018)

Hi i'm currently running 2.673 code on my MSII v3 box.
It's in my '91 BMW M5.

I'm experiencing a strange issue, my idle MAP reading is about 76 +-2. I did chose the right MAP in my Sensor Calibration window (MPX4250AP). However when it try to use the Generate Table windows, they ask for idle characteristics... however they won't let me enter my rpm kpa of 76 at 950rpm.

Am i missing something?

Thanks
Gene

MAP at idle should be around more say 30. Something is up...... With the engine off did you compare your MAP reading to the air pressure where you are at above sea level to see if the MAP is operating correctly?

A.J.

yeah, map shows ~100 when engine is off, but while running i'm only getting 76 kpa... what the

If this helps, the engine has 6 throttle bodies, connected together by runners for idle control, i attached my MAP to the same spot as where the stock Idle Control Valve feeds into the Intake.

Guess since i have 6 TBs i can't trust my MAP reading.

My reading does dip to like 30 when i'm off the throttle (i assume stock DME closes the idle valve when above 1500rpm)

Sounds almost like the point you've tapped the plenum/manifold is above the throttle plate!

I'd also plug a standard analog gauge onto the port you've used to see what reading you get. Should be like 16-20in hg or like 50-30kpa (might have done the conversion to kpa wrong in my head there!)

no actually the point i'm tapping into is roughly in between cyl 3 and 4 runners.

I'll take a picture tomorrow, a rough description would be like, the runners are cast in pairs, cyls 1&2 have one 3&4 have another pair, and 5&6... then the pairs are joined by 3/4" tubes for idle control.

i'm tapping right into the middle of the two middle runners. It's not a custom tap, there was already a tap there from BMW engineers (un-used on this engine, just covered by a rubber cover)

Maddios,

I have the same problem, my idle map is around 80KPA (310deg Cam) and the table genrator in 2.6 will not accept values above 60KPA for idle MAP. I only found this yesterday so I hope one of the gurus will have some kind of a fix??

Jon

yeah same here, i guess the stock m5 cams are 264 but i bet mine got 282 cams

I mentioned this to Lance in another thread and his take on it is that the table generator is designed for fairly average engines and to give the majority of users a workeable starting point. With more extreme engines the only option is to tune it manually. I see his point as you cant make the default table all things to all men. Looks like we will have some work to do!

Jon

guess i'll give it a shot this weekend, can't do it at the moment cuz i drive the car to school every morning lol.

I was hoping to be able to use a base map but guess i'll just maybe try to use the generator and then shift the numbers up