Lexus AFM questions

[SkyHawk Ecks]

Just for shits and giggles, I put in my Lex AFM I got the other day to see how it would affect my fuel cut.

Started it up and no idle problems at all. I am definitely able to exceed the stock limitations of the fuel cut. I'm playing it safe, I have my AVCR set to .90 bar. One thing I noticed though, is that when I do about 30% throttle and higher, to boost, it'll lurch/bog and then goes through all of the RPMs fine. The bogging feels like fuel cut, but no check engine light comes on or anything. Later on I took out my EFI fuse and reset the ECU. Now at cold it has really crappy idle, 500 and below. Warmed up, it idles perfectly, 600-700.

Is this what's to be expected? I'm taking it off tomorrow, but is this what will happen if I get 550s? Or will I still need correction from an SAFC?

 

[oscolivar1]

so for shit and giiggles... you put a lexus afm which is 25% bigger than stock on stock 440 injectors and what you expect to boost like crazy to exceed stock fuel cut.:nono:

You need bigger injectors (550injecors) and a good tune (SAFC).
and other things as well, but im sure you can search.

 

[starscream5000]

Bigger injectors aren't needed if the car is tuned right, but this one isn't .

 

[oscolivar1]

Bigger injectors aren't needed if the car is tuned right, but this one isn't .

True, you can, but if you decide to go with the stcok injectors they better be cleaned and flow tested.

 

[starscream5000]

True, true!

 

[SkyHawk Ecks]

I didn't expect to boost like crazy. I drove the car for a few hours, it's not going to blow up, nor would it.

And I don't necessarily need 550s, but yeah, I would need clean and flow-tested stock injectors. What sort of correction would I be making with an SAFC? 25%, right?

 

[mkIIIman089]

If you add ~25% on the SAFC you're negating any benefit (besides maybe less restriction?) that the AFM gave you.

 

[isnms]

You don't want to take out more that ~20% on the safc, messes with timing.
So much searching/reading to do.


subscribes to thread to watch :naughty:

 

[Nick M]

While it is true that the ECU will try to correct the lean condition that you created, why do it the hard way? Put the correct injectors in before you lean burn the engine.

 

[SkyHawk Ecks]

Well duh.

Driving it for a few hours isn't going to burn my engine. My engine's a freak. It was only for experimental purposes.

 

[Nick M]

You don't need a few hours. Just one run into boost when the 440's are past their safe point. I don't know that you were there, just pointing out what should be known.

Since the comments prior said that the ECU will correct it.

 

[SkyHawk Ecks]

You're right, but going .05 bar past the fuel cut limit isn't going to blow my engine.

 

[rumptis]

Putting a LEX on a stock engine will cause it to run lean, doesn't take much to melt a piston or blow a HG if you are running very lean and boosting on it.

 

[starscream5000]

:werd: You can't say that you didn't hurt anything unless you can prove it with something like A/F ratios.

 

[isnms]

But he only did it for a "few hours"

edit: that was facetious

 

[mkiiSupraMan18]

^ exactly... Who hasn't done it?

*edit*
/\ What he said...

 

[rumptis]

I have a LEX laying around, maybe I will try this proven method.

 

[mkiiSupraMan18]

^ I'll bring the bleach. :boink:

 

[isnms]

^ exactly... Who hasn't done it?

I haven't.