[Gmecm] Help with unusual BLM's

[ahuxtable at sola.com.au]

Thanks for that Gene (and Steve - See further down)

As for your problem Gene, that was some of the first things I checked on
this engine because oddly enough, it has a misfire problem.

I changed all plugs, leads, Cap, Button ignition module and ECM and it
still does it.  It's not all the time, generally when hot and I rev over
4k RPM.  It sorta sounds as if I'm hitting rev limit but I'm not.

Still trying to find the cause of that one (which is also partly why I
hooked up the lappy)

Steve, I get it now.  The BLM's being low is not that it's physically
rich at that point, moreso that it is removing fuel because it 'was'.
Makes so much more sense now that fuel is getting in somewhere else (As
Dave mentioned). Will have to play some more.

Thanks for your help guys!

Andrew

-----Original Message-----
From: gmecm-bounces at diy-efi.org [mailto:gmecm-bounces at diy-efi.org] On
Behalf Of Randy & Gene
Sent: Tuesday, 28 March 2006 11:10 AM
To: gmecm at diy-efi.org
Subject: Re: [Gmecm] Help with unusual BLM's

     Hi Andrew, today I solved a 3 year mystery as to why my 1993
Pontiac
Sunbird with a 3.1 V6 did exactly what your engine is doing. I had taken
it
to a dealer and Mr. Goodwrench charged me close to $1300 Cdn and
couldn't
fix the problem in 13 hours. I took it to another fellow who had worked
for
GM and he changed the upper and lower manifold gaskets citing there was
a
vacuum leak..$500...and another emissions shop charged me close to $200
for
telling me it had a vacuum leak near the back of the engine because when
he
sprayed a liquid in that area the engine sped up a bit......this car has
a
full body kit installed otherwise I would have towed it to the wrecking
yard...anyway...I bought a 1992 Sunbird with the same engine for
$350....bought a manual and laptop from E Bay and proceeded to swap
parts
out...O2,EGR,TPS,MAP,ECU and even checked every mile of cable harness
for
resistance...everything including injectors were swapped, throttle
body.........nothing helped...then I decided to start over with
basics....a
simple compression test was first.....pulled all of the spark plug boots
first then took out the 3 front plugs and number one from the
back....number
3 was missing....or at least half of it was...part stuck in the boot and
the
other in the head......compression was good on all and when I supplied a
plug from my parts car the 3.1 lit up like it was new..........you can't
imagine my joy........the only code I ever got was a 45....rich O2...it
had
been replaced...a broken plug........make sure your basic stuff is in
order
first and good luck.....Gene

----- Original Message ----- 
From: <ahuxtable at sola.com.au>
To: <gmecm at diy-efi.org>
Sent: Sunday, March 26, 2006 8:04 PM
Subject: [Gmecm] Help with unusual BLM's


Hi all.  I've been trying to work out why for some reason my car has
been running rich.  I just always assumed that it was the O2 sensor
playing up - Until yesterday that is...

I logged some data and the highest BLM I saw was 120.  Most being around
115 so my engine is running fairly rich. So, the computer thinks that
it's running rich and it actually is = not O2 sensor.  Next I thought it
might be the CTS or MAT sensors but logging them, it's all normal.  CTS
reports running temp of ~85DegC (184DegF) and MAT is reading as expected
too.

What else could be forcing the engine to run rich?

Thanks
Andrew
_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
http://lists.diy-efi.org/mailman/listinfo/gmecm

_______________________________________________
Gmecm mailing list
Gmecm at diy-efi.org
http://lists.diy-efi.org/mailman/listinfo/gmecm