Lex-550 settings and problems--Way lean at idle Pig rich under boost

[SPD TRP]

Car ran great stock--just wanted to put that out there.

Now with big turbo and all other doo-dads it is all over the place. (AFR's)


With the safc NEO I have to add 12% at idle or it goes crazy lean >17.1.

When boost ramps up at a pound or two she stays at about 11.7-12.4, then more boost comes on and we shoot to 9.0.

Fuel pressure is at 32psi idling and vacuum connected, 41 idling and vacuum removed.

Checked for boost leak, didn't find any--all hard pipes, silicon couplers and t-bolt clamps.

New intercooler--driftmotion.

High trims on neo are at -12%.

Wondering how many other guys out there with 550's and the lex mod have had to add so much fuel at idle and pull so much under boost.

I thought it would be pig rich at idle with 550's

Any thoughts would be appreciated.

Thanks
Wayne

 

[Supracentral]

Something is wrong. Either the electronics in your AFM are bad, or something else is horribly wrong.

The Lexus and 550's should run close to stock. Close enough that the factory ECU should be able to run the car fairly well with no adjustments at all.

 

[SPD TRP]

That's what I thought. Did swap in a known working afm, then it went way rich at idle--9.6:1 on my innovative w/b. Put my afm in his and it didn't run right. But I couldn't tune out the rich idle with the safc neo. That's what has me puzzled, or one of the things that has me puzzled.

So I'm thinking, a bad afm right. So after doing the afm dance for a while swapping this one and that one got one that seems to be working.

It is still pig rich under anything more than 4 or 5 lbs of boost. 9.0:1 afr

If I had a massive vacuum leak wouldn't that make it run way rich?
But, it pulls a steady 22 inches of vacuum at idle.

 

[cnewingham]

I was always under the impression we shouldnt tune low throttle points with a piggyback due to the ecu always trying to re correct the a/f's. I have my safc set at low thr 69% with no adjustments and 70% for high thr with no fuel taken out until 2800 -8 and then up -12 and until 5200 at -15%. I didnt add fuel anywhere. I could be wrong about making adjustments while the ecu is in closed loop but everything I have read has lead me to this conclusion.

 

[SPD TRP]

Thanks for the reply. Are you also running the lex 550 safc setup?

I will go out right now and try the idea you gave me.

Wayne

 

[Supracentral]

OK, 3rdtimearound, forgive me if this sounds too basic, but with the problems you are having, let's go WAY back to basics.

First questions:

What brand injectors?
Have they been flow tested?
What fuel pressure regulator are you running?
Is it a 1:1 rising rate regulator?
What fuel pump do you have?

Suggestions:

You say your base fuel pressure is at 41 with the vac line removed. Try tweaking that down to 33 psi. The base range is 33 to 40 psi (nominal), I've even seen people go as low as 28.

Try that first before you mess with anything else.

 

[935motorsports]

Supracentral is right, we have to scale back your whole setup.

Also you have a Walbro, another variable.

The Lex 550 combo can be used as is. But when you add FPR, Walbro, SAFC, all kinds of things start happening.

Does your wideband have data logging?

I would forget the NEO for now and dial in the Lex using the AFPR to fix the idle issue. Does your lexus have an adjustment screw?

 

[SPD TRP]

OK, 3rdtimearound, forgive me if this sounds too basic, but with the problems you are having, let's go WAY back to basics.

First questions:

What brand injectors?

rc 550's

Have they been flow tested?

yes


What fuel pressure regulator are you running?

aeromotive

Is it a 1:1 rising rate regulator?

yes

What fuel pump do you have?

Walbo gss-341


Suggestions:

You say your base fuel pressure is at 41 with the vac line removed. Try tweaking that down to 33 psi. The base range is 33 to 40 psi (nominal), I've even seen people go as low as 28.

Try that first before you mess with anything else.

UPDATE----------------------------------------------

did these things before I read your post, out in the garage.

moved the throttle points to low--69 and high to 70 and put the low setting at 600 rpms back to 0 correction and just sat there and waited for it to finally come back down from way lean to almost stoich 14.9--15.2 at idle.

Started to take small amount of fuel away in low settings and it seems to be responding to the corrections at part throttle cruise.

sorry about the confuguration--tried to respond to each question.

 

[Supracentral]

Ok, sounds like you are closer. The next thing you need to do is tune for Vf.

 

[MmmBoost]

on my setup, after making adjustments on part throttle, i was getting a totally unpredictable WOT. so, i zeroed everything out. i connected the safc map sensor input wire to the VF output wire on the ecu (forget what color wires) and i use the sensor check menu to get a quick look at vf at all times.

next i toyed with the afm adjustment screw, and drove around for a long time with no safc corrections. the vf eventually stayed almost all the time in the 2-3 volt range. then i started making corrections at high throttle, and i havent had a problem since.

btw, i have my low and high throttle settings at 69/70 also. good idea!

 

[SPD TRP]

I think maybe I was impatient in my expecting it to idle correctly quickly.

When It was idling lean, the Vf would float between 3.75 and 5, indicating to me if I am correct, the ecu sensing a lean condition and adding fuel, that's why I went ahead and added fuel at idle with the neo, but 12% with 550's sounds like alot to me.

My o2 sensor is pretty new, maybe 6 months old from Toyota, maybe its getting shotty.

Didn't check the Vf since I took away fuel at idle since its almost sleepy time for me. Now the neo is set at 0 correction at 600 rpms and a gradual reduction of fuel, around -4%, at other points in the low setting.

But I will do it tomorrow, you can bet.

Thanks for your help.

Wayne

 

[SPD TRP]

on my setup, after making adjustments on part throttle, i was getting a totally unpredictable WOT. so, i zeroed everything out. i connected the safc map sensor input wire to the VF output wire on the ecu (forget what color wires) and i use the sensor check menu to get a quick look at vf at all times.

next i toyed with the afm adjustment screw, and drove around for a long time with no safc corrections. the vf eventually stayed almost all the time in the 2-3 volt range. then i started making corrections at high throttle, and i havent had a problem since.

btw, i have my low and high throttle settings at 69/70 also. good idea!

I may reset the ecu and zero everything out and try your method, whats your fuel pressure?

Thanks for the info, this tuning stuff is kinda hit or miss with the miss getting pretty costly.

 

[Luigi]

I may reset the ecu and zero everything out and try your method, whats your fuel pressure?

Thanks for the info, this tuning stuff is kinda hit or miss with the miss getting pretty costly.

Hey Guys,

I have been having the exact same issue with basically the same exact set-up? I even had Justin tune my car before the TX2K7 and it fouled out all 6 plugs coming back home to Austin. The air/fuel was tuned perfect.

Justin felt I had an ignition issue since my car only breaks up under boost over 10-12 psi. It runs really geart until I get on the turbo? On the dyno it started to sputter over 10 psi and we only got around 350 hp.

I also have a new JT57 turbo and this issue has been driving me nuts. I have changed the CPS, ignitor, checked all plug wires, tried a new coil pack and it has a good ground. I even tried the Lexus AFM module to see if my Toyota electronics went bad with no luck.

It appears we are both fighting something similar? This thing has kicked my butt for over 2 Months now. I am glad it is not my daily driver! I have been playing with the air/fuel settings and now I am sure it is all screwed up. I have re-tuned it as best I can without a dyno run but it still runs like crap under boost and loses power and sputters between 10-12 psi.

When I get on the boost I can see that it is dumping way too much fuel on the wide band? I have not tried the 02 sensor yet, any ideas would be greatly appreciated. I cannot seem to clean it up with the AFM.

Thanks!:aigo:

 

[SPD TRP]

Hey Guys,

I have been having the exact same issue with basically the same exact set-up? I even had Justin tune my car before the TX2K7 and it fouled out all 6 plugs coming back home to Austin. The air/fuel was tuned perfect.

Justin felt I had an ignition issue since my car only breaks up under boost over 10-12 psi. It runs really geart until I get on the turbo? On the dyno it started to sputter over 10 psi and we only got around 350 hp.

I also have a new JT57 turbo and this issue has been driving me nuts. I have changed the CPS, ignitor, checked all plug wires, tried a new coil pack and it has a good ground. I even tried the Lexus AFM module to see if my Toyota electronics went bad with no luck.

It appears we are both fighting something similar? This thing has kicked my butt for over 2 Months now. I am glad it is not my daily driver! I have been playing with the air/fuel settings and now I am sure it is all screwed up. I have re-tuned it as best I can without a dyno run but it still runs like crap under boost and loses power and sputters between 10-12 psi.

When I get on the boost I can see that it is dumping way too much fuel on the wide band? I have not tried the 02 sensor yet, any ideas would be greatly appreciated. I cannot seem to clean it up with the AFM.

Thanks!:aigo:

Man, I feel your pain.

I have an update

With the neo set at no correction--all zero's

O2 sensor plugged in
idle afrs 16.7-17.1
idle Vf 2.2

O2 sensor plugged in
1500 rpms afrs 13.9-14.2
1500 rpms Vf 2.2


O2 sensor unplugged
idle afrs 16.78-17.4
idle Vf 2.2

O2 sensor unplugged
1500 rpms afrs 14.8-15.3
1500 rpms Vf 4.8


When it was stock, I remember forgetting to plug the O2 sensor back in and the afrs went from stoich to around 12.4 and pretting much stayed there until I plugged it back in.

With the O2 sensor plugged in, the Vf goes to a max running lean condition and tries to compensate, but at idle the Vf should be going to zero since it should be trying to richen up the mixture.

Could the O2 sensor just be out of whack, but not enough to throw a code?

 

[SPD TRP]

well to update, I had an injector insulator, that was leaking causing a vacuum leak and my lean idle conditions.

It is still very rich under boost. Still trying to figure that one out.

Wayne