[Supras] Fwd: Re: need help with maftpro

[Jim Jobe]

Too low of fuel pressure will result in spray pattern issues.  You should
increase the fuel pressure higher and rely on the maft-pro to adjust the
pulsewidth back down.  IMO 30psi with vacuum is about as low as you want
to go but ultimately I prefer to set the base pressure to what the injectors
are rated at.

I would suggest you remove the Mines ecu and put your stock one back in.
There's no telling what Mines has done - they may have richened it up
even and probably have advanced the ignition timing map which would really
kill things if you don't have the maft-pro controlling the ignition timing.
You should understand why this is an issue.  The MAFT-Pro and all of the
other piggybacks lie to the ECU by tweaking the AFM signal.  The ECU uses
the AFM signal to determine ignition timing too.  If you tweak this signal
down to compensate for larger injectors you ALSO affect ignition timing
which is more advanced at lower air flow rates.  Add in an already tweaked
ignition timing table optimized for a stock car and you're asking for
problems.

Now, your problem - sounds like it's way too rich so you need to adjust
the maft-pro to remove fuel.  I would suggest you get a wideband O2 sensor
before proceeding any further.  680's are just over 50% larger than 440's
so I would start with the afm scaling feature to reduce it by the equivalent
amount, then tune carefully with a wideband O2 sensor one small step at a
time until you're seeing 11-12:1 at just a few pounds of boost (try
it a few hundred rpm and a few psi at a time).

On Sat, Jul 29, 2006 at 03:52:10PM -0700, Clark E. Wireman wrote:
> well i backed the static fuel pressure down to 26 psi and noticed that on the afr tracking my min tps was set to 4 my tps only reads from .4 to 3.4 so i adj that down to 2.9 and adj my mainscale to from 0 to 9 it finally builds boost not much before it cuts out again its like a fast stutter not like a fuel cut..... but at least i got some boost and the blowoff is popping lol any other ideas? i really need to get that lc1 installed most importantly huh?
>