Fuel cut still

[mcammarn]

Story: so I'm still for some reason hitting fuel cut. I had installed a ddp, and figured I would still hit fuel cut w/o a bigger fuel pump. I was running stock. And yes I did hit fuel cut.
I never turned up the boost, it turned itself up I noticed, 16psi is where it's at now. It was at 9 when I had the stock elbow and 3 in dp.
So I go and buy a 320 lph aem fuel pump. I still hit fuel cut.
Why is this? I figured it would've gone away.

My mods:
57 ct26
560 inj
Lexus Afm
Afpr set to 40
320 lph fuel pump
J tube delete
3in turbo back, cooleze dp to cat to tanabe medallaion
2.5in ic upper cooleze piping
Spearco ic
Hallman bc
Hks ssqv
Turbo timer hks

So I can at idle rev the motor without anything happening, and also, there is no codes.
When I had hit fuel cut while driving, a cel would light up, but then turn off 2 seconds later.

What can I do to get rid of this!
I do have a safc2, but not installed yet. Is this the problem? Then it would need to get dynod tuned.
Also, I have a aem wideband, just not hooked up really. What I mean by that is, I need to re wire it. I have turned it on at idle, and its reading ok.

I checked for boost leaks, and none found as well.

Any help would be great!

 

[jake8790]

Neither the fuel pump or the lack of safc2 are causing fuel cut. It shouldn't be boosting to 16 psi without any boost controller, I would check to make sure the wastegate is working properly. I run a very similar setup to yours and it seems to hit fuel cut around 19-20 psi.

 

[mcammarn]

I forgot then to mention, waste gate is shimmed. I put a couple washers on both sides. And with going from stock elbow to integrated elbow, it would go up a little, wouldn't it?

 

[Nick M]

What can I do to get rid of this!

Remove the shims and install an electronic boost controller of some sort, and set it to 14 psi until you find the boost leak you don't have.

 

[IndigoMKII]

Remove the shims and install an electronic boost controller of some sort, and set it to 14 psi until you find the boost leak you don't have.

I'd have to agree with Nick here.

 

[mcammarn]

Well I've got a hks evc 6, but I was tryin to sell it. I just figure the hallman is top of line Mbc.and wouldn't need the evc. But I guess I could try that.

 

[mcammarn]

And do you think the shims is really causing myself to hit fuel cut? Shimming just gives you more boost.

 

[Nick M]

It is hard not to do it....

 

[mcammarn]

The shims are easy to do, I put them there.lol but I was asking in general would that cause the problem.

 

[7M4EVR]

Lol yes in general...that IS the problem. Why not install the safc and wideband correctly and street tune it safely until you can get to a dyno?

 

[Suprapowaz!(2)]

!WARNING! I'm not a professional and please take my advice with a grain of salt.


Rewire WB, set Lex AFM adjustable screw all the way out, tap into E1 & Vf1 in diagnosis block with voltmeter, start adjusting fuel pressure to satisfy AFR's while within a good range with your Vf readings (2.5-3.5). You want more "unmetered air" coming in so the afm electronics won't detect and compensate for it. Afm sends signals to the ECU by way of Hz, and when you reach a certain predetermined Hz ECU activate FC as a fail safe. In my car when I reach 2000Hz I hit fuel cut. I know this by tuning with my MAPECU. When more of that "unmetered" air passes through you have to compensate by bumping up your fuel pressure a little.

Afm screw all the way out. At idle set fuel pressure and monitor afr's to around 14.7. Go out for a cruise and monitor afr's & Vf. When you have it cruising (no boost) around 14.7 and somewhere between 2.5-3.5v on the voltmeter then you should be ok. That's street tuning in closed loop operation.
Go full throttle and watch your AFR's! Chances are you're going to be running rich. Make sure you don't run lean though. If you're running a little too rich you can try to lean it out a little, but you will affect your closed loop tune. If you tune it to run 3.5v Vf then you've pulled enough fuel to still be ok and you might have leaned it out a little under heavy load. You just have to play with it a little. Don't do any more than 11.5afr under full boost. Try to keep you afr's in the low 11's.

Good luck.

BTW, pulling that screw all the way out might help raise your FC up a little but not by much. You will still get FC eventually.

 

[mcammarn]

Lol yes in general...that IS the problem. Why not install the safc and wideband correctly and street tune it safely until you can get to a dyno?

Don't know how to street tune.i know how to hook it up though

 

[IndigoMKII]

Lol yes in general...that IS the problem. Why not install the safc and wideband correctly and street tune it safely until you can get to a dyno?

Doesn't need to be tuned for the lex/550 mod. Both are 25% bigger than the stock parts, thus running like normal.

 

[jake8790]

Don't know how to street tune.i know how to hook it up though

Suprapowaz just gave you a very helpful and detailed explanation!

 

[Poodles]

Unshim the wastegate....

The extra flow through the DP is allowing more boost and you're boosting way too high, it's really that simple...

 

[Another MkIII]

Why is your wastegate shimmed if you have an MBC?
-AM3

 

[supraguy@aol]

Most people with stock ecu and stock injectors hit fc around 11-12psi.
You added 25% more air and fuel. Guess what a 25% increase over 12psi is?
You've gotten where you should be. Back off the wastegate shim by a washer. See how it goes.

 

[Nick M]

You added 25% more air and fuel. Guess what a 25% increase over 12psi is?

On top of that, the T04E compressor is much bigger than the CT26. Backing the screw out of the Lex Meter is an ok idea to defeat fuel cut. If you have the screw slightly under flush from the housing, it will hit fuel cut around 18 psi with that compressor.

 

[Suprapowaz!(2)]

Backing the screw out of the Lex Meter is an ok idea to defeat fuel cut.

Yes, as long as you add fuel. If you back out the screw without adding fuel you're run leaner. Monitor your wideband.

 

[Poodles]

As the original 550cc/lex mod already runs rich (like the factory setup) and he's running 560cc injectors instead, he's probably fine.

Not that you should be messing with the screw anyway as it's set for idle IIRC.