Unfortunatly I don't know what could exactly be causing that but all I can say is WOW THAT IS LEAN!!!
 
But yes do check for vac leaks.
Is there an adjuster screw on the lexus afm?
 
Hunt
 
----- Original Message -----
From: trembath@world-net.co.nz
To: Supra Club of NZ Mailing List
Sent: 24 December, 2003 2:59 PM
Subject: [sconz] Lexus Mod Problem

Hey Guys,

I have recently fitted 550cc injectors plus a Lexus air flow meter to my
7MGTE. Before fitting them I checked my standard mixture with an air/fuel
ratio meter and it was fairly constant at 14.7:1

Since doing the Lexus mod the upper mixture stays pretty much the same, the
idle mixture on startup is about 16.5 then goes back to 14.7 after a while.
When throttling off during deceleration the mixture leans out severely and
goes off the scale (>20:1).

I have checked heaps of things, changed my AFM sensor, throttle body (had
bored mine out to 65mm, have reverted to a standard 60mm one now), adjusted
the TPS position as per TSRM but this has not fixed the problem.

Thought it may be either:

1. Faulty TPS (when I had it off it seems to spring back very slowly and as it
appears to be pushed up by the throttle body and returns by it's own spring I
wondered if it can't close as quickly as the throttle body)
2. The modified Lexus AFM screw is not long enough (It's roughly the same
length now as on Reg Riemers article, and it's wound all the way in)
3. The computer needs more time to learn the new setup.
4. There's a leak somewhere after the throttle body which draws in un-metered
air after the throttle body is closed and the plenum vacuum increases.

I don't want to cause any damage to the engine by this 'leaning out', is this
possible on deceleration?

Anyone got any ideas?

Cheers
Rob
New Plymouth



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