HAs anyone with a MS gotten a stable AFR at idle? mine moves around a bit and wont stabilize for shit.


I am getting real sick of playing with it and am starting to see why Hahn went with the 8 injector setup.

Terry

Yeah mine isnt great either, and i'm still playing around with the settings. Idle is even worse when it's controlling spark haha. I sort of think the stock ECU is messing with things though, esp when running spark. The stock IAC freaks out a bit when all that stuff if disconnected form the ecu. The IAC like to surge a bit, and rpm keeps going up and down a bit. I unplugged the IAC and drilled out the adjustment screw cap on the TB, and opened up the throttle a bit for idle. It worked pretty good, but a cold start you have to keep your foot on the gas until you can get some heat into the motor. I'm thinking of a fast idle valve will work great with the MS, and i have an idea of how to do it..just need to get around to it.

I saw your thread at the MS forum, and that one guy has good advice about keeping the VE bins equal around your idle map/rpm. It does help a lot. Try running closed loop at idle too. Or try not running closed loop at idle, and see which seems best. I just think with a bit more time we all can figure some of these quirks out..I'm real picky about my idle too man :) I wouldnt trade the MS for an 8 injector setup now though..this thing is just too sweet. Puts the 8 injector or any other fuel setup to shame haha

Yeah he had two points really, keep all points around idle equal and also try a valley to the bin used most. The valley worked a bit but after x amount of time i start leanign out or things start to back to where they were. My thought about the Factory ECU has been there from the start. Tomarrow i will reconnect the factory injectors up to the ECU so it thinks it has control and see if anything changes.

Terry

I disconnected my IAC too, it helps a lot with the stability with idle AFR's. The engine will idle around 700 when cold, and around 1400 when warm, but at least it doesn't surge anymore and the AFR stays right around 13.5:1. The engine will now also start up and stay running the on the first attempt, which I was never able to do with the IAC still hooked to the stock ECU. My timing is about 8-12 degrees at the 1400 RPM idle.

Originally posted by ner947
I disconnected my IAC too, it helps a lot with the stability with idle AFR's. The engine will idle around 700 when cold, and around 1400 when warm, but at least it doesn't surge anymore and the AFR stays right around 13.5:1. The engine will now also start up and stay running the on the first attempt, which I was never able to do with the IAC still hooked to the stock ECU. My timing is about 8-12 degrees at the 1400 RPM idle.

Well i'm having cold start issues too..Never really had that problem with 022i6 code though. I can see the PW in MT go up when cranking, motor fires for half a second, then PW goes to 0.0, then motor quits. It's like the MS isnt keeping the injectors on after the cranking PW time ends..I had to crank it like 10 times to get it to start. Did this with fuel only, and fuel+spark. I've left my IAC plugged in, gave it 15 degrees of timing at idle, and it seems to be doing ok..it's a little touchy at first, but after a 5 minutes or so, the IAC seems to stable out. It was worse when i had the timing at idle around 5-7 degrees. The IAC had NO difference in the A/F ratios at idle either. The IAC is NOT the issue for the idle A/F problems.. One more thing to note, is when the IAC is unplugged, after running some higher boost, the pressure pushed in on the IAC pintle, and I had a bit higher idle after that run..It's going to need to be removed and plug the passage hole.