Hi guys,

Last year I started building my Miata. This forum has been very helpful so far, but I'm getting lost on the MS tuning part. The car is a euro 1998 NB with 1.8. For now only minor parts have been changed engine wise: Wideband (MTX-L plus), FlowForce 640cc's, DW200 pump, turbo prep like an intercooler in the loop, bov, IC piping. I've put together a MS3x and installed with help of Trubokitty, car is running, so far so great. Right now I'm trying to clock in the fuel map but I've noticed a weird quirk which I don't understand. Whenever the engine is on high load or WOT, I see AFR going out of range on lean and RPM dies. Looking at PW and duty cycle it's far from 100%. See screenshot below. I've tried to lower or rise the fuel in the corresponding cells, but see no change.



I've checked for rev limiters, CLT, boost etc but cannot find anything out of the ordinary. I would be very grateful if someone could have a look and give me some pointers how to continue. (The log data shows first idling, then free revving with WOT and at around 1020s driving). I'm willing to feed cats for exchange of service.

 

Re calculate required fuel and run VEAL

 

You'll need to auto-tune the entire fuel table to get it to work well. If that particular spot goes super lean, add 20% to fuel in the higher rows to get the ball rolling, then auto-tune from there. Also, when you autotune, don't punch it. Ease into every cell on the fuel table gently from the surrounding cells. Then you'll use accel enrichment to get the WOT tip in dialed in.

 

Isn't Required Fuel basically a multiplier? Mine was set at 20, after recalculation 4.7. However when I run VEAL now, the values in VE table rise well above 255, which means they're maxed out. This is also the reason why my Required Fuel was set to 20, to keep the VE table values low. Below a screenshot of VEAL with some cells retuned.



Ok, thx! Will do more careful tuning.

 

Can't view the tune from here. Did you change the injector dead times to match the flow force injectors?

 

Yeah, I've changed them according to the 4 bar settings at https://goflowforce.com/instructions/

 

Pretty sure the EUDM NBs use a manifold referenced return style fuel pressure regulator like the USDM NAs with a 3 bar base pressure.

 

Hmm I do have a return line on the manifold, wasn't sure about the pressure though. I'll try with the 3 bar base pressure settings.