Just installed the PLX M-300 unit and having a hard time tuning with it. I have an HKS S-AFR and the o2 was installed under the rear seats so I think its far enough back. I can't get the idle to lean out some it sits around 11.5-11.9 and I have the idle set at
-55%. On full throttle the afr stays around 11.0-11.9 and I get a spike of 12.1 at around 5,500 rpm. After I let of the gas it goes to either lean sign or it says air which I think is ok, is that ok?

I have a rewired walbro with resister pack in the trunk, 720's on top and rc 550's running 10-10.5 psi on a BNR stage 1 turbo. Full exhaust and TID. Greddy front mount. S4 jspec motor, stock ports miles on motor?

Are the A/R's ok? Or should I try and lean it out more?

Haha or I'll just turn up the boost to lean it out!

Can this setup handle 12 PSI?

 

I think 11.5 - 11.8 is good A/R's. I think anything above 12 is to lean. Do some research on the forum most people are in the 11.5 area.

 

what size walbro are u using

 

On a 88 you should be able to lean out the idle with the variable resistor. What does the wideband do when you turn the variable resistor to the LEAN direction?????

 

I'm using the 255 walbro. I had to lean 1-3% for full throttle past 3000rpm at ten psi, thats at 14.7-15.1 volts to the pump with a third gen alternator and 12.1-.4 at idle. But I can't seem to lean out the idle, cruising it will stay around 14.7-15 A/R's.

I'm going to try and richen up that spike I get at high rpms.

 

I haven't even messed with that yet. Is that the thing next to the boost sensor with the some kind of glob in it?

 

Yes. It should have a R and a L embossed on the top of it. Dig the glob out. There will be a screw there. It will turn appox one half of a turn upon which it will hit its stops. Clockwise for rich, anti-clockwise for lean. You should hear the engine react when doing this, as in the idle rising and fallig a touch.

Generally a RX runs best at idle with a afr of approx 13afr plus or minus a couple of tenths. Too much towards 14afr and it will want to stall/miss/ act funny.

 

I'm going to have to mess with that now. I remember messing with that on my non turbo rex but I didn't even think of messing with it on this one. Maybe I can get it to idle better and not like its going to flud itself. I'll tune it to 13.0 and see what thats like instead of 11.5-11.9, maybe I'll get better gas mileage to.

Will that mess with the rest of the settings that I have for the rest of the rpm's?? Or will I have to retune again?

 

Rotary engines like to run rich at idle.
There's no reason to lean out the idle if it's running okay.

Lift-off lean condition is normal.
There is basically nothing you can do about it, and it doesn't hurt anything.



-Ted

 

Yeah it runs ok, I see 300mmhg vac at idle. I just wanted to see if I can smoothen it out some, just seems like its on the verge of flooding itself.

I think the wideband was a good buy so far, I had afr's untuned before the wideband at around high 9's to mid ten's. It feels better at higher rpms now.

 

wideband = good investment