Tuning help needed

christer.medin at lennoxintl.com christer.medin at lennoxintl.com
Tue Jun 15 19:14:46 GMT 1999


Last night it was rather late and we couldn't really read the FP gauge we had taped to the windshield.  We set it at around 48# at idle, that should be within reason, shouldn't it?  By the way, the car's using 30# injectors.
Richening it up bigtime sounds like the best way to start... hopefully I can report tomorrow morning that the car's running like a champ. :^)
Thanks, guys!

Christer

----------
From: 	MIME :realsquash at yahoo.com
Sent: 	Tuesday, June 15, 1999 3:08 PM
To: 	gmecm at efi332.eng.ohio-state.edu
Subject: 	RE: Tuning help needed

This could be the result of so many things...  What is
your fuel pressure?  Can you monitor it while driving?
 Does it only do it while driving?  What if you rev it
up in the driveway?  Fuel pressure problem or a fuel
map problem.  Just for grins, add some fuel to that
whole area of the fuel table.  Go way overboard and
make it rich just to make sure you are getting enough
fuel to the injectors.  IF you can't get it to run any
different with the added fuel in the table, fuel
pressure/volume is most likely the prob.

SqUaSh

--- christer.medin at lennoxintl.com wrote:
> Thanks.  At the time, we had it set to stay in
> closed loop until 60% throttle, which we didn't get
> to at any point during the test drive.  We were
> going to try leaving it in open loop next to see if
> that makes a difference at all... trying to narrow
> down exactly _where_ it's having a fit.  Does the
> 4mv O2 reading make any sense? It seems odd that
> it'd drop like that within a second...
> > Christer
> > ----------
> From: 	MIME :realsquash at yahoo.com
> Sent: 	Tuesday, June 15, 1999 11:01 AM
> To: 	gmecm at efi332.eng.ohio-state.edu
> Subject: 	Re: Tuning help needed
> > Check to see if it switches to open loop when you
> push
> the gas.  Try just pushing the gas slowly, but all
> the
> way to the floor.  Don't just mash the gas!.  If it
> runs crummy this way, then add/remove fuel from the
> main fuel table.
> > Squash
> > --- christer.medin at lennoxintl.com wrote:
> > Hi, just subbed to this list -- I have a friend
> who
> > just got his car together again, with a 379
> > (de-stroked 400) SBC, TPI intake, and Haltech
> > computer.  We finally took it for a spin
> yesterday,
> > and it runs great until you push the gas a little
> > extra; at 25%+ throttle and around 2000-2500 RPM,
> it
> > stumbles _badly_.  The O2 readings are in the high
> > 700s right before then, and vacuum is at around
> 24",
> > but as soon as you step on it, the O2 reading
> drops
> > to 4mv, and vacuum to 5-7".  If I were to wager a
> > guess, I'd say it appears more related to a sudden
> > stab at the throttle than the RPMs.  Right now
> > timing is setup for 10 degrees initial, and 36
> > degrees coming in full at 3K RPM.  Since you guys
> > live and breathe ECMs, I was hoping you'd have
> some
> > input here.. thanks!
> > > Christer
> > > > >
>
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