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Discussion Starter · #1 ·
I was reading some info. on this in the faqs and threads. I'm hoping that you folks can give me some clear ideas on how to get to this problem fast.

First my modds:
Lex 400 maf, TurboX-s BOV, HKS AFR, A/F gage in pod, Boost gage in pod, HKS DP 3 inch all the way back with a high flow res.
The injectors are stock and so is the rest of the fuel system.

Problem:
*When I stand on the throttle hard I get a slight pinging. My A/F gage reads that I'm still running medium to rich.
* When I hit 4200-4400 rpm I hit fuel OR boost cut. My boost gage is reading about 11 psi.

Question:
Pinging, should be timing and can be adjusted. I advance the timing right?
On a LEX 400 Maf,can you adjust the srcew out to raise the fuel cut?

Any help here would be of a great used to me thanks...Kurt Sr
 

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Pinging - you need bigger injectors. You are running too lean because of the effect of the larger air flow meter, EGT's are going through the roof, therefore detonationis occurring. You will need a new bottom end before long if this continues! Put it on a dyno with a good wideband O2 setup and get your air/fuel ratio checked, you want to see ~11.5:1 under boost. IGNORE your narrowband a/f gauge, it is NO use for tuning! Don't mess with the timing, DEFINITELY don't advance it!

You can adjust the screw out to raise fuel cut a bit, FC at that low boost level suggest a boost leak or some other problem though.
 

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Acting my age
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Hey Kurt... I'll get flamed for this, but you have seen it work on my car... Until you get injectors, run the HKS AFR at +20% throughout the RPM range.. This will essentially raise your fuel cut 5-10% and force the ECU to provide the additional fuel. At 11psi you are pretty safe with this.. Before I had the injectors I ran 14PSI with +19% throughout and had perfect A/F's and NO fuelcut ever.. But like everyone always says.. get the injectors too... They make for some realy fun.
 
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Discussion Starter · #5 ·
Adam, thanks for the input..it dose help.

Matt,
I have the afr set at 25% few out the fuel / rpm range.

If you could give me a call, that would be helpfull.

Phone # 916-995-0038 Or home 987-1784

You are the teach! and I could us your help!

Kurt Sr
 

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Moderator, l337 M0d3r4t0r
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12,328 Posts
Sounds lean and sounds like you have a boost leak for FCO at 11 psi but then again you are adding 25% which is defeating the point of having the lexus AFM..

GO to the DYNO right now find out what the car is doing for a/f ratios...

Then you know where to go from there.
 

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Go All Electric
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1,183 Posts
I hope your HG has been torqed down well/replaced.

1)Get a good EGT guage! Autometer supposedly makes a great EGT guage and sensor set-up ... but a lot of companies make these so just go with whoever you like.
*EGT and A/F guage are DECENT indicators for you to potentialy be warned of problems in your engine. An EGT guage will not tell you when one of your cylinders is running lean/hot. The narrowband A/F guages aren't exactly "relaible". Check out the FJO A/F guages. You may also want to look into getting a wideband 02 ... <---- this is your best bet/best tool for tuning and basically the only tool for tuning to really rely on.

You asked if you can adjust the screw on the LEX AFM to rasie "fuel cut" <--- really spark cut. YES, you drill the aluminum that covers the head of the screw so that you can get to it with a screw driver ... "tune" with it as you wish. BUT ... you are already running too lean/or atleast your TCCS thinks that you air due to the air signal coming through the AFM. Adjusting should work, just monitor your EGTs and A/F closely with the tools I mentioned.

You may want to get an AFPR, FUEL PUMP etc upgrades to your fuel but it shouldn't be completely necessary with your set-up if you are tuned and ot trying to run too much boost/power.




People already replied with what I would have, but I will reiterate a few things.

1) It will work with better tuning.

2) Do NOT adjust your timing.

3) It is lean right now.

4) Possible boost leak for such low "FC".
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See the following thread about increasing fuel cut with the stock fuel system, just ignore the fact that it is about using the stock AFM to do it because the main idea is raising fuel cut with the stock fuel system whether or not you are using the stock AFM or LEX AFM or any other mothod to do it. It also has pictures of different angles of the LEX AFM and the adjustable screw.
Raising "Fuel Cut" with stock AFM.

I suppose you checked out the LEX+440 sticky, but just in case:
LEX AFM with stock fuel STICKY.

Most importantly, get on the phone with Adam.

Good luck! Let us know how everything works out. Best regards.
 
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Discussion Starter · #8 ·
Well thanks for the replys.

I'm going to go back to the stock MAF until I get the 550s.

The car ran good with the stock and never hit fuel cut. It did ping a bit even on the stock MAF. I have retimed the car and it was about 3-4 degres advanced. There is no pinging on the LEX Maf now or the stock. But I'm going to leave the stock in for now.
I know that if your going to do modds it needs to be done right.

Thanks for your input.....

Kurt Sr
 

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Go All Electric
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GONE14S said:
Well thanks for the replys.

I'm going to go back to the stock MAF until I get the 550s.

The car ran good with the stock and never hit fuel cut. It did ping a bit even on the stock MAF. I have retimed the car and it was about 3-4 degres advanced. There is no pinging on the LEX Maf now or the stock. But I'm going to leave the stock in for now.
I know that if your going to do modds it needs to be done right.

Thanks for your input.....

Kurt Sr

Ok. BUT ... you do realize that this will work "RIGHT" if it is tuned "RIGHT" correct?

I am always "gung-ho" about "If you are going to do something then do it right", BUT, that doesn't always mean that you have to do a lot of something (add a lot of mods) to get it "RIGHT".

If you want to boost the stock ct26 to about 15psi (reach the full potential of the stock turbo, which it sounds like you are doing):

Read the "Raising 'Fuel Cut' with stock AFM" thread that I linked to above.

Do the PVC intercooler pipe mod for help with flow and your EGTs.

What you are trying to do is easily achievable. It just hasn't been the norm because not everyone thinks that it is "safe".

Stcok intercooler (not really the IC pipes though) and stock fuel can be used fine for full potential of the stock CT26.

Whatever you decide, good luck. Best regards.

EDIT: Due to speeling/grammar/punctuation so that you could better understand what I was saying:D ;) .
 

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Acting my age
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Hey Kurt...

If you are free swing by my place tonight.. T and I will be working on that red car I brought down.. I'll call ya before I leave work..

M
 
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Discussion Starter · #11 ·
Awidesupie,
Opions and thought are what I am after. It helps decide which way to go. I do have respect for what you are saying. At this point I'm flying blind on my own on something that I have not delt with.
I can swing wrenchs with the best of them, but when it comes to the turbo's I'm still learning. Again thanks for your help.

Matt,
Cool dud! Yeah give me a call on my cell # It would fun to hook up again. See what kind of touble you have gotin yourself into!..lol

Kurt Sr
 

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Go All Electric
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GONE14S said:
Awidesupie,
Opions and thought are what I am after. It helps decide which way to go. I do have respect for what you are saying. At this point I'm flying blind on my own on something that I have not delt with.
I can swing wrenchs with the best of them, but when it comes to the turbo's I'm still learning. Again thanks for your help.

Matt,
Cool dud! Yeah give me a call on my cell # It would fun to hook up again. See what kind of touble you have gotin yourself into!..lol

Kurt Sr
Well, I 'm glad that you appreciate it. Make sure to read the links that I posted. Talking to Matt is going to help you out a lot. BUT ... don't think that you HAVE to wait for injectors/other fuel pressure mods to run 15psi of boost on the stock turbo ... because you don't have to. The set-up can be tuned to run perfectly.

Off-topic: My family owns real-estate in Sacremento. One of the properties is in my name. Maybe we will meet up someday when I come over there. I will be busy on the east coast for a while, but keep in touch.

Best of luck to your set-up. If it s opinions/facts and thought you want, you can ask me, and if I know anything and am able to get some time to respond then I will do so.

Best regards.
 
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