FC with Lex and 550 combo on 2JZGTE??

[ihiryu]

Hey guys, I've got lex afm, rc550's, AFPR, and SAFC, I'm still hitting fuel cut! I'm running an DaveH kit and it's going to 15 psi, and I'm hitting fuel cut!

Also, it seems like I'm having break up around 3k-5k ish. I don't know if it's the safc, or ignition break up. If I go part throttle, I still get the same symptoms.

Sorry, i've been dicking with her all night after work, and I'm home after 5 hours of highway pulls, and I can't figure anything out!

Safc settings are all over the place. My zt-2 shows 10:1 AFR's around 3k around 4k it goes to 11-12:1 range, and it breaks up the entire time.

Spark plugs are stock 2jzgtte gapped to .28.

Dang I almost forgot to mention, 2jzgeT w/ 7m electronics, 2mm HG w/ arp studs. And HKS 272 intake side cam. I didn't know BC made a set until I had the engine in the car running.....

 

[suprastanger507mgte]

set your tps correctly?
do you have some kind of boos cut controller installed?

 

[Fletch124]

Not really terribly surprising your hitting fuel cut with a lex afm and 550s. I hit fuel cut on my 7m with a lex afm, 550s, safc, and a upgraded CT at 17-18psi.

 

[ihiryu]

Crap and I just realized that this went in the wrong area, i meant to put it in the 7mgte area...sorry plz move mods

No boost cut controller, I'm kinda worried about those things, I'm afraid of things on how I don't know how they work. Remember I'm still a toyota noob!

Anyway Fletch what's my next step now? I thought the lex afm and 550's would cover me until 20+ psi....

 

[grimreaper]

add more fuel pressure and pull more with the safc to get higher fuel cut, there are limits though.

fuel cut all day at 16psi on my setup with the cooler weather now.

 

[tissimo]

Crap and I just realized that this went in the wrong area, i meant to put it in the 7mgte area...sorry plz move mods

No boost cut controller, I'm kinda worried about those things, I'm afraid of things on how I don't know how they work. Remember I'm still a toyota noob!

Anyway Fletch what's my next step now? I thought the lex afm and 550's would cover me until 20+ psi....

The AFM measures flow, so 20 psi on a ct and 20 psi on a 60-1 or bigger turbo is very different.

 

[dok33]

Not sure on the fuel cut, I couldn't get past 15psi on mine without tons of breakup. I'm going to try .022 plug gap and see if it clears up. Might be worth a shot if you're up for takin' the damn y-pipe off...

 

[dok33]

Bringing this back from the dead, you figure out the fuel cut issues?

I got my breakup issues solved a while ago and recently cranked the boost some more. I'm hitting fuel cut at 15-16psi in 4th gear with the Lex/SAFC setup (680s, 45psi base pressure, E85 for fuel) with a MP T70.

Looks like we both may be at the limit of the Lex setup as far as FC goes. I have read that adding fuel pressure and/or larger injectors and pulling more fuel with the SAFC can raise the ceiling a little. Hoping the experts can chime in...

 

[hottscennessey]

You're correct. Fuel cut is mainly just a value (in hz) that the AFM reaches, once it hit's that value it cuts fuel.

SAFC's work by modifying that value by, given by the AFM, and feeding it directly to the ECU, so the ECU see's the value the SAFC want's it to. By upping the fuel pressure and/or going to larger injectors, you're adding more fuel to the mixture.. by subtracting fuel with the AFC you're then evening out the mixture, and putting yourself further away from the value which triggers FC.

BTW I know this is basic stuff Josh and you already know this.. but it's always good to have this information available for others. In your case I would go with larger injectors, because I'm not positive how much fuel pressure you can safely run. Hopefully some of the experts will chime in on that.

 

[dok33]

Thanks for the reply Scott! Def good to get all the info out there, guess it's time to start shoppin for some bigger injectors...

ihiryu-how bout you buy some 880s and I'll trade you for my 680s and then we'll both be all set

Edit-anyone know if MKIV top-feed (used with aftermarket MKIV rails) injectors will fit in the lower intake? Found a deal on some Delphi 880s but wasn't sure if they'd fit...

 

[hottscennessey]

no problem, if they're top feed they'll work for the 2JZGE

 

[dok33]

Sweet, read somewhere that domestic injectors were 14mm and the 7M/GE needed 11mm but I can't find the thread.

Here's what they look like:

Guess I can just run 2 7M grommets on the lower end like on my RX7 injectors, just wanted to make sure they'd fit in the rail

 

[frontierguy25]

I have a Lex AFM and a SAFR with 660's with a bolt on 60-1 turbo and I don't hit fuel cut until 28psi. Only did it once. But none the less I have my AFPR set at 34psi with the vac line on and I run 20psi all day with no fuel cut.

 

[hottscennessey]

I ran domestic injector on my 2JZGE, they were the only injectors I ever put on that did not have any leaks the first time. I had a horrible time trying to get the Lucas/pte injectors not to leak. I think all I did for the domestic injectors was double up on the fuel rail spacers? I had some laying around from a 7m. It's hard to remember.

 

[hottscennessey]

I have a Lex AFM and a SAFR with 660's with a bolt on 60-1 turbo and I don't hit fuel cut until 28psi. Only did it once. But none the less I have my AFPR set at 34psi with the vac line on and I run 20psi all day with no fuel cut.

He's running E85, and a larger turbo so I think he's spot on.

 

[dok33]

Sweet, there goes some more money into the Supra I've already got doubled-up spacers and lower grommets on my RX7 680s so I should be good to go.

Checked my FP this morning, it's actually at ~60psi with the vac line off. Otherwise it's a bitch to start cold. And yup on the E85, 680s are actually on the small side since I need 30% more fuel. Basically what I'm running right now is the equivalent of running 480s on gas with the Lex/AFC setup, no wonder I'm hitting fuel cut lol...

 

[dok33]

Bringing this back from the dead...

After mucking with o-rings for a couple weeks I finally found some on McMaster Carr that would work and got 'er up and running again. I'm now limited by my WG spring, with the boost controller all the way up I can hit 18psi in 4th (which is hella-fun btw), AFRs are a solid 11.8-12:1.

Unfortunately I hit FC this morning when it was cooler out laying into it in 4th, so I'm not sure how much headroom I'm going to have. Need to find some threads on the Lex AFM adjustment screw, I remember something about adjusting that pushing FC up if you bypass more air or something...

 

[ihiryu]

On the AFM if you look at it from the side, you'll notice there's a small cap there, once you open it up there's a screw in there. Turn it out all the way out so it can bypass the most air.

 

[ihiryu]

Oh the car is down, I spun a bearing. I think i'm either going AEM now or 1.5j. The damn 7m ecu is just a pita ha ha.

I'll keep you updated

 

[dok33]

Damn that sucks. Good luck with it, I've thought about AEM more than a few times but I've already spent too damn much on the car.

I'll mess with the screw tonight, also need to find a bolt to go in the top of my WG so I can add some preload for more boost!