Running the Lexus AFM questions?

suprafanatic

New Member
May 25, 2007
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Greenwood, IN
ok.. i have a 60-1 turbo on the car, 3in DP which is running open. im running the stock afm right now geting ready to get the lex afm and injectors after i get the money. right now my car is running very rich running 9-10 psi.. but im geting some kind of cut off at 10 psi.. so when i get the lex afm would i be able to put it on the car and run it ok if i only boost like 10-12 psi? till i got the injectors? since it is seeming to run very rich right now.
 

sneakypete

Regular Member
Jul 18, 2007
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Central NJ
hahaha.... i was in that same boat. i would get the injectors and lex afm at the same time. wideband is a great idea... gives you piece of mind. actually if you are interested, i am selling my rc 550 injectors and have 2 lex afms. pm me if you are interested.
 

MA70Snowman

New Member
Oct 17, 2006
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San Diego
mkIIIman089 said:
Fix that 1st.

improper tuning/timing, and/or bad o2, check ur CPS timing and your TPS. but first see where your base timing is at w/ a GOOD timing light (not some cheap 20$ autozone special) also there's a post here somewhere that you can actuall see +/- if your running VERY rich/rich/ideal/lean/very lean by checking the o2 signal. i believe it was JJ that had the post somewhere. check those then look at going up.

and please don't run just the lex afm. YES you can, NO you won't kill your engine. but there's to many ifs/ands/thens/buts around that. 25% more air needs 25% more fuel. bottom line IMHO. if you want cheap, source some rx-7 turbo II 550 injectors from a rx-7 site, and send them out cleaned/repaired i got 6 of them and cleaned for under 200$ and i'm boosting 14.5 psi no problems with them and a lex afm. and my AFRs are at 11.8 under boost.
 

mkIIIman089

Supramania Contributor
Mar 30, 2005
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Ohio
MA70Snowman said:
i'm boosting 14.5 psi no problems with them and a lex afm. and my AFRs are at 11.8 under boost.
LOL. 16 psi, lex AFM, stock fuel except walbro. 11.0 after fuel pulled under WOT ~6k RPM.

How many "if"s was that you said?
 

SUPERIUM

Low Postage Member
Nov 29, 2005
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Buffalo, NY
Im going to run just the lex afm on my 87 and hook up a wideband to get some a/f ratios in a week or so and post with the results. My car already runs rich as it is with stock injectors even at 12-13psi so I dont think its going to run lean enough to cause any issues but we'll see.
I know a few MKII guys with 7mgte swaps that just run the afm with stock injectors at 12-15psi and/or in the 300-400rwhp and never had any issues.
 

Poodles

I play with fire
Jul 22, 2006
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Fort Worth, TX
seen the dyno sheet first hand...

sure, it's rich at first, gets under boost still rick, but gets dangerously lean the higher you go.

It's NOT worth melting your engine for. There is NO reason to run a lexus AFM with stock injector unless you have a way to tune in more fuel (this means at either a walbro with an AFPR and an SAFC, or alcohol injection)

Keep in mind loads on the street can be far worse than a dyno, and that's when you destroy your engine.

Go ahead and do it, it's not my engine, but don't be pissed when people say "I told you so."