starting off with Lex AFM and AFPR

grimreaper

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Jul 2, 2008
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ive searched and read and searched more along with read some more. when using the lex afm and a afpr with 550 injectors, is the ideal setting goin to be to max out the adjustment screw (out) then add fuel pressure (or take it away) to get the idle down? then add pressure to keep wot in check?
isnt the whole point to get more air through with out the pcm seeing it (raising fuel cut) and add fuel to keep the added air that isnt metered in check? hence the idea that you max out the afm and raise fp accordingly?

also at this point with out a piggy back to add more fuel through injector pulse width, you either tune for idle, or wot (car has sp61gt on a 7mgte with all fuel upgrades minus walboro hitting fuel cut at 14psi) correct?
 
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grimreaper

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Jul 2, 2008
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shaeff;1087032 said:
Read this:

http://rob.carlile.home.mchsi.com/lexus/lexus1.htm

Then, if something is unclear, ask away! :)


the tweaking of the afm screw and afpr is different for each car- got it
max setting on the afm screw (all the way out) wont work with all cars though even with added fp to make up for the added air?


i understand the volume of air at 14 psi from the 61gt to the ct26 is alot more, so if im maxed out on the afm screw will more fuel (add walboro) raise the fuel cut level with the 61gt?

If fuel cut is the tccs seeing to much air and saving it self from a possible lean condition, how does more fuel raise it unless the tccs can recognize that there is infact more fuel avaliable?

im a think out loud kinda guy sometimes (mostly with new to me concepts).
thanks for the help, i enjoy learning this stuff :icon_bigg
 

thevork

ShoarmaTeam Member
Get a wideband sensor. Then you can finetune the lexus afm and fuel pressure to an optimum.

It's better to get a good idle @ 14.7 with a Vf from around 2.25 using the AFPR.
If done, then use a piggyback sysem like an S-AFC to tune the car in open loop (WOT)

hth
 

grimreaper

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wideband is on the way, and im not a fan of piggy backs. standalone in the future, just wanted more info on the ability of the tccs to realize there is in fact more fuel, thus raising fuel cut, or is it simply a matter of getting air around the tccs and nothing to do with fuel?