Lex AFM Results

[bountykilla0118]

Well guys i spent today playing around with the Lex AFM and the stock fuel system. I am not sure how some of you guys were able to use the Lex AFM on the stock fuel system and stock settings. I think it would have been find with AFPR even without a pump.

I pulled the fuse EFI fuse and also the main the relay and installed the Lex AFM and deleted my SAFC-II settings. On the stock settings at idle was getting 17.1+ and once the car warmed up it was even leaner. So I had to add fuel 8% across the board. That put the a/f ratio closer to stock numbers roughly 15.3-15.6 and at cruise it kept the a/f ratio close to 14.7 with it peaking around 15.3.

So I changed my timing again and it put it at 8 degrees before TDC and I started to boost and it was way to lean. I was seeing 13+ so I added more fuel and I ended up adding pretty much 12% across the board.

If I had AFPR i think it would have been perfect even without the SAFC-II, since I would have bumped the fuel pressure up maybe 5psi and it would have been pretty close to the numbers I am seeing now.

I put the timing back to 10 and now the car is boosting happy with the low throttle corrections of +9% and high throttle +12% across the board. My peak a/f during WOT is 12.2 and at idle I am seeing VAC of -21 IN-Hg

[suprafanatic]

how much boost were you able to run? and any good horsepower gains?

[bountykilla0118]

umm i hit fuel cut around 16psi but that probably b/c i added so much fuel if I had scaled back some fuel and added fuel using an AFPR it might be able to go 20+

yea it felt alot faster but i am so used to more power that it wasnt all that .... 300rwhp isnt much after you you get hooked on 450+

another thing to note is that when i pressed/released the break my A/F ration changed a good bit i might need to take a look deeper into that.

[tweak666]

another thing to note is that when i pressed/released the break my A/F ration changed a good bit i might need to take a look deeper into that.

i'm having that same problem, i can't figure it out. someone said it might be the brake booster or a vacuum leak. someone else said it might be a bad ground. i changed all my vacuum hoses yesterday, and i still have the problem. i'm gonna have to test the booster and check all my grounds

[Nick M]

There is a check valve in the booster.

You do have bigger injectors with that Lex meter?

[bountykilla0118]

I cant see a bad ground being the issue there with you. Cap off the nipple that goes to the brake booster and see if that helps ..... it will just make braking a bit harder until you put it back.

[bountykilla0118]

There is a check valve in the booster.

You do have bigger injectors with that Lex meter?

Are u asking me or him? I am on the stock fuel pump, FPR, and injectors. I am using one of the AEM widebands and SAFC-II

[isnms]

You got your Lex screw all the way in?
Since you're trying to do it on stock injectors/fuel, you will probably need, at least, the longer Reg screw.

[GrimJack]

The Lexus AFM is supposed to be balanced by larger injectors.

You won't find many people running the Lexus AFM on a stock fuel system... at least not that still have an intact engine.

[shaeff]

To follow tradition, I always post this link in these threads when they pop up:

http://rob.carlile.home.mchsi.com/lexus/lexus1.htm

[ians13]

that's very odd that you had to add fuel under WOT seeing as how I had to pull fuel out and lots of it, starting at 22% ending at 12% to get a afr of 11.5 I do have a walbro and afpr, but even without that my car was very rich under WOT same as stock. And I made 301hp on 14psi with this setup and the car is running great. I want to start a thread to see just how many people blew there motor with the lex afm and stock injectors "tuned" because a lot of people say you will blow your motor, I wonder if there just saying that because they seen it in person done it or just because every one else is saying it I want proof , I have searched I seen one car that blew a motor running 17psi, now that’s just stupid on stock fuel setup.

[bountykilla0118]

I find it funny that you find me funny since I said I am on the stock fuel system and you are posting that you have AFPR and a Walbro apples and oranges. You are pulling to much fuel at 22%. Read below.... That walbro move so much fuel than the stock unit. What do you have your fuel pressure set at? Is your J-tube by passed?

http://www.supramania.com/forums/showthread.php?t=27784

[sethron71]

Hey for your wide band issues do you have it grounded through an isolator? Any change in voltage to the wideband or feed back through a ground will make it change, I.E. braking tail lights come on...ect Try turning the headlights on and see if the same thing happens.

But none the less good information even though I would recommend it to anyone not running a wideband and having tuning capabilities.... Lex, 550's, AFPR, Wideband, and S-AFC II FTW!

HTH,
Seth

[Nick M]

Are u asking me or him? I am on the stock fuel pump, FPR, and injectors. I am using one of the AEM widebands and SAFC-II

You are the one who said you are lean running an AFM designed around a certain CFM and corresponding injectors, but you don't have the injectors. So yeah, that would be you.

[bountykilla0118]

Nick the point i was making was that i dont see how other who have posted that their were able to run the lex afm without any changes with the tune.... I agree with the other members who say dont run the lex afm without a good tune. Was the point I was getting at.

[isnms]

...were able to run the lex afm and 550s without any changes with the tune....

Fixed it for you.
I don't think you have seen anyone post that they could run the lex on stock injectors without tune. You will have to cite it if you have.

[WhtMa71]

Thats cool. I never really thought about being able to tune a lex setup not using 550s. I was under the impression that it was a big nono and was pretty dangerous but you have proved that wrong..Although a walbo would be good insurance.Good info.

[Quin]

I am currently running stock injectors with a Lex

[bountykilla0118]

Quin ..... we had some PM's a while back about it but i was trying not to be too specific :) but are you guys running on the stock settings like fuel pressure and stock ECU fuel maps w/o any piggy back scaling?

[Quin]

I remember talking, do not remember what about lol

[bountykilla0118]

I was asking about your current mods and fuel cut ...... your response was that you started to lean out at 18psi or so i am going to dig it up. I am sure I saved that convo

[bountykilla0118]

ha and i quote!

01-13-2008, 02:31 PM

Yeah, stock 440s.

Full 3" turbo back
Intake
AFPR
J-tube bypass
SAFC (original, not I or II)
3" IC piping
Spearco replica IC
HKS BPV (don't get it, it's shit. I have issues with comp surge)
62-1 CT26 (Supposed to be an HKS wheel, not sure)
Spec Stage 3+ Clutch
Lexus AFM

01-13-2008, 06:35 PM


I don't remember exactly, but I'm at the end of them. The previous owner tried to dyno tune it for 18PSI but it ran too lean. I'm bouncing off 12:1 in full boost. It's been tuned damn well, I'm getting 20-25 MPG with light boosting. If you're thinking of attempting this setup, I'd recommend a Holset HY35 or HX40 instead of the 62-1, as it's supposed to be unreliable, and 550s, as running a Lexus AFM without 550s raises fuel cut past where your fuel system will actually go.

[isnms]

...were able to run the lex afm without any changes with the tune....

AFPR
J-tube bypass
SAFC (original, not I or II)
Equals changes with the tune

Obviously Quin and Suprafanatic are the ones you need help from. I'll bow out.

[Quin]

Turns out my 62-1 is a 60-1 btw

I never said or implied I was running untuned with a Lex and stock injectors. My car runs like shit for about 500 miles after you reset the ECU, and seeing as Nate's acted exactly like mine when we put my Lex on his car I'm fairly certain the TCCS adjusts to it

EDIT: Edited previous post, Nate is still on stock AFM, I'm an idiot

[bountykilla0118]

Equals changes with the tune

Obviously Quin and Suprafanatic are the ones you need help from. I'll bow out.


isnms but i am not asking for help i am just stating my results I understand lol but man there was a thread a while back where the guy was stating that he pulled the efi fuse and the ECU relearned its self back to a good tune ....... I said i was going to make a thread about it and post my results and I agree/co sign/affirm that the lex afm and the stock 440's dont work on without tunning!!!!!!!!!!!!

I dont see the ecu relearning its self with the lex afm and this is after i tested it myself.

[Nick M]

Your TCCS will adjust, in closed loop. Not open loop which is start up, WOT, or heavy load.

[HommerSimpson]

Everything I have read on here .. putting just the LS400 maf on and keeping the 440 injectors = engine blown up.......no place on the INTERNET is anyone running a the lexus maf and stock fuel and having it work right.. Id put your old maf on till you can do the upgrade the way its supose to be done.. maf injectors and fuel pump....
Id hate to see what the tops of your pistons are starting to look like..

Now understand this is just my 2 cent and just my opinun....

[bountykilla0118]

Barts daddy go have seat or play with some more pipes lol j/k man keep doing what you are doing ......No harm meant but seriously many people have it working right with a car that has been tuned.... again my point of this thread is that the lex afm and stock 440's need to be tuned!!! My a/f are perfect and i am sure the top of the pistons are just fine. A friend of mine has been on the stock 440's and lex afm for a long time but he has a walbro and AFPR and I dont

"Now understand this is just my 2 cent and just my opinun"

Thanks