J N's MiniRam backfire

[JN]

Don't take this as a "flame" but as just how I see where your at, and they
have pointed you

What?

I really beginning to sound like you generating a Alpha-N system, with the
MAF for trimming.
That is a huge huge amount.
Them "knowing" what the problem is so far isn't working.

What?

50 engine running, vac off,
then 50 running vac on, and blip the gas should see definitely more then 50
ie 53ish possibly more depending on cam.

I am talking with the vacuum line on and you juice the gas the pressure goes
to 50 or slightly higher as the vacuum is reduced.  In other words the WOT
pressure is set to 50 psi.

How good are you at moving the MAF scalers and stuff?.

I'm learning.  Ed Wright has seemed to nail it pretty good though.  I have
compared his scales to stock scales and normal cruise I do not have a
problem.

maybe writing Mark
Romans, and ask him about how much time he has in his calibration, for a
hotrod the MAFs are just so much work, and unless you can correct the
inherit
weaknesses in that MAF, I just wish you luck.

Mark has helped me tremendously with understanding MAF cars.  I even have a
copy of his chip (#49) which he graciously donated to me.  Please don't take
this a flame, but you do seem kinda anti MAF.  I want to learn all I can
about MAF cars and then maybe I'll make the move to MAP.  As far as which
code I'm using i don't any attention to that.  Is $32B not the 89 code?  Is
this the 88 code?

As far as giving out Ed's MAF tables, I bought that chip from him before
starting off on my own.  I don't think he would appreciate his work on the
internet.  I can tell you they are very different.  Also what I don't
understand with hot rodding MAF cars such as hotter cams intakes etc. is
that the MAF see's a certain amount of air passing through it right?  Lets
assume the MAF and intake tract are stock.   Lets say we go from a 350 to a
396 cid.  The 396 motor at say 3000 rpm will be sucking more air in than a
350 right?  Ok.  More air = more fuel and O2 trims the values.  Am I
thinking about this too simple?  Anything above say 4500 RPM is PE vs RPM as
a trim.  Correct?  My thought is how much time do you spend over 4500 RPM in
normal cruise?  What am I missing?

Jason
----- Original Message -----
From: "Bruce Plecan" <nacelp at bright.net>
To: <gmecm at diy-efi.org>
Sent: Thursday, November 09, 2000 11:54 AM
Subject: Re: J N's MiniRam backfire


>
> Don't take this as a "flame" but as just how I see where your at, and they
> have pointed you
>
> >     Some answers to your questions.  Car is an 89, 165 ecm $32B.  I have
a
> > chip from fastchip that I have been playing with that has modified MAF
> > tables for a ported MAF.
>
> You happen to know what the base BBC is?, and a copy of the MAF
corrections.
> I'd be interested in seeing what they did.
> Why not start with the 6E code?.
> So your not running screens?...
>
> > I also tried my stock timing map and other
> > various things.  I have been concentrating on my pump shot.  I called
TPIS
> > and they knew right away what my problem was.  They said I bet your
> getting
> > a big backfire through the intake.  They told me to modify the pump shot
> > tables and that should do it. I increased the pump shot by 45% and that
> did
> > nothing.  I plan on increasing the pump shot more and experimenting.
>
> I really beginning to sound like you generating a Alpha-N system, with the
> MAF for trimming.
> That is a huge huge amount.
> Them "knowing" what the problem is so far isn't working.
>
> >  Fuel
> > pressure is set to 50 psi line off.  If you blip the gas, the pressure
> > spikes to 50 like it should.
>
> ?
> 50 engine running, vac off,
> then 50 running vac on, and blip the gas should see definetly more then 50
> ie 53ish possibly more depending on cam.
>
> TPIS suggested raising the pressure to 60 psi
> > and I explained to them that for whatever reason, my multecs seem to
start
> > locking up at pressures over 50.  With that in mind, they suggested
going
> to
> > a 24 pound injector.  I have a set of 30 pounders that I have been
saving
> > for the 396.  I figured that they were too large for a 350 with ported
> heads
> > and a slightly hot cam.
>
> 50-60 to get rid of a sneeze?.
>
> Raising fuel pressure is a universal enrichment.
> Just like changing Injector sizing......
>
> There is a basic malfunction here.
> One of which is that, I don't see the reasons in carving up a MAF an
> expecting it to read right.
> Running around, vs running correctly has always been an issue with me.
> Ya, it's easy to take a we got it running a quit attitude, but I just get
> tangled up in the correct / best possible end of things.
> bruce
> >
> > Thanks,
> > Jason Norris
> > ----- Original Message -----
> > From: <timsiford at hushmail.com>
> > To: <gmecm at diy-efi.org>
> > Sent: Thursday, November 09, 2000 9:14 AM
> > Subject: J N's MiniRam backfire
> >
> >
> > > Jason sent me an XLS spreadsheet with data from a scantool that shows
a
> > > backfire happening when he blips the throttle.  Car = 1987 Vette w/
> > MiniRam.
> > >  Its pretty interesting.  (Jason, I am posting here because I can't
find
> > > your e-mail, thirdgen appears to be down, and I also want to share
this
> > > info with others here).
> > >
> > > The data clearly shows Jason 'blipping' the throttle from off idle.
> There
> > > are 4 data points on the throttle blip and you can clearly see the O2
> > volts
> > > going from the switching behavior at idle (TPS=0.53V) to 0mV on a
> Throttle
> > > blip.  The data is below.  This appears to be a fueling issue
> (expecially
> > > when viewing the SA in relation to the throttle blip and LV8).  Its
> > undetermined
> > > as to whether or not it is a PROM fueling issue or a mechanical
fueling
> > > issue.  What do you guys think?
> > >
> > > RPMs,TPS, O2, AFR, Knock, SA, LV8
> > > 875, 0.530, 836, 14.7, 0, 25.4, 57
> > > 875, 1.630, 712, 11.7, 0,13.8, 189
> > > 875, 3.310, 292, 11.7, 0,15.9, 177
> > > 1300, 2.94, 0, 11.8, 0, 28.2, 175
> > > 1725, 0.90, 13 ,14.7, 0, 45.5, 124
> > >
> > > Jason - quick question for you.  The MiniRam has ZERO provisions for
> EGR.
> > >  What PROM are you running?  Are you running $6E code, $32B code?  Is
> your
> > > PROM image based off an original TPIS image or did you start with the
> > stock
> > > image as a base?
> > >
> > > A separate issue is that IMHO, knock -should- be detected and isn't.
> > >
> > > Tim
> >
>
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