Still hitting fuel cut??!!

[Supra_32]

So to start my car has the following:
-57 trim
-550cc injectors, Walbro with 12v, and Lexus afm
-Intake and exhaust and intercooler all 3 inch
-Apexi muffler
-Profec B push in dial boost controller

Before I did my 550/Lexus upgrade I purchased a fcon with a Fcd and gcc. My car when I bought it was running 12psi no problem. Once I installed the f con thinking I could up my boost to 15psi, as soon as I get past 12psi my car slams me hard and drops the revs and check engine light comes on. No power.

Trying to sell my f con right now as I am saving up for standalone, after spending 1000 bucks doing the Lexus/Walbro/550 mod my car does the same thing.

My boost controller doesn't make a difference on high and low mode.
I set low to 12psi and the sharp and mild dial in the middle.
As soon as my car gets past 12psi a big slam and check engine light comes on for a few seconds.

What gives? Is it my boost controller or waste gate? Hell I thought a stock ct26 can even run 15psi?

Please help. Thanks

 

[hvyman]

What code?

check for boost leaks.

 

[suprarx7nut]

A stock CT26 will hit fuel cut somewhere around 12-13 psi. My 50 trim (close to a stock CT26) hits fuel cut right at 12.5-13. The turbo can push a little more air, but not much. Even a 57 trim will be pushing a lot of hot air much past 13.

The Lexus/550 mod should give you about a 25% increase in fuel cut room. If you're hitting FC at the same point then a boost leak makes sense.

Can you monitor AFRs? a wideband can help show if something's going weird all of a sudden when you hit 12 psi.

 

[Supra_32]

Ok I'll check that out.

 

[Supra_32]

So I am not running a afpr.
Finally got my wideband hooked up. Idle at cold start is rich around 11. But once I get going it settles down to 14. At normal non boosting highway cruising my afr is good, around 14.5

At boost around 10psi my afr is up around 13-14.
Shouldn't it be like 10-11 aka super rich?

I have a fair amount of back fire and popping when downshifting and it seems to run rich on de acceleration.

Normal driving and shifting without boost seems high/rich around 11-13. Once I get a comfortable gear, usually 3rd and back off the throttle it settles down to 14.5

 

[Supra_32]

Bump

 

[suprarx7nut]

My 7MGTE with a 50 trim CT26 and all stock electronics, NA fuel pump, fresh, clean Turbo injectors, 10-12 psi is consistently 8-11 AFR on boost. If you're at 13-14 under load (boost) that's pretty lean.

With an AFR that lean i would not expect a boost leak. A boost leak should make you run real rich. You might just be at the fuel cut limit on a 57 trim. Remember, fuel cut is just based on the amount of air your meter sees. A 57 trim pulls in a lot more air than a stock CT-26 at any given pressure level. Fuel cut is around 13 psi for a stock CT-26. For a 57 trim, it may be about where you are (10-11 psi).

With the 550s and Lex AFM you should probably have a piggyback to control fuel better. Naturally the 550 and Lex AFM are pretty well matched, but not perfect. Combine that with a unique engine with an odd quirk here and there and you really need to monitor and control that stuff which you can't do with a stock system.

Good luck.