So I've been driving my MS1 boosted 1.6 for a while now and mostly it runs great. Idles great, starts great, and once warmed up it cruises and fueling in boost is great too.

My one problem is that for about 90-120 seconds when the car is warming up (coolant temp around 110-120) the car runs super lean (19:1 AFR) and awful. Then you wait about two minutes if you can keep it running and it runs great again. I have tried to overcompensate for this by dumping fuel in with the warm-up enrichment but I know something is wrong and that is kind of a band-aid. Maybe something glaring is wrong. Most of my tuning has involved VEAL and since the car runs so well otherwise I have not messed with much. Some screenshots and my msq attached. Thanks for help!

 

What's the location of your IAT?

 

About 12 inches from the throttle body, a fairly "cool" spot. My cold starts and cold enrichment seem fine, car runs good. This happens about 5 minutes into driving the car, and only briefly, and then everything is great again. But it's really painful while it's happening.

 

Is it getting warmer in your area for summer?

 

Have you done anything with the air valve on the intake manifold. If you are letting megasquirt control the idle valve for warmup I suggest removing or plugging the air valve.

 

Ok I'll try that. Or maybe I don't want MS to control idle during warmup? It idles perfect everywhere else except this one condition. I don't want to screw something else up trying to fix.

Yes it's getting warmer but this is unaffected by temperature. Car runs great hot or cold out, just awful for about 2 minutes when it's warming up (not immediately, it runs great on cold starts for the first 5 minutes or so, then randomly awful, and then perfect again)

 

There is a reason Mazda got rid of the air valve. It isn't necessary when idle can be controlled by the bypass valve for warmup.

 

Just to add info to this, the lean condition happens throughout the map at all RPMs. So WOT is 18:1, cruise is 19:1+ AFR. Would the idle valve have anything to do with that?