[Syty] Broke & Stumped!

[Jim Sloan]

Happy New Year Dennis!
 
I've had hardware problems with several of the 10-1 adapters.  You could
swap back to the stock memcal (and map sensor) to rule that out, if your
build isn't too radical.
 
I usually keep at least one spare ecm for a substitution test, and have seen
quite a few fail in weird ways.  Let me know if you need one.
 
Sometimes it helps to go back to the basics, and follow the diagnostics in
the service manual http://syty.org/old/d
<http://syty.org/old/d&e-code44.html> &e-code44.html .
 
Just a few ideas, if you haven't already tried them.
 
Jim  


  _____  

From: syty-bounces at syty.org [mailto:syty-bounces at syty.org] On Behalf Of
DOlivares
Sent: Sunday, January 01, 2006 7:36 PM
To: syty at syty.org
Subject: [Syty] Broke & Stumped!
Importance: High


Who watches The Watcher?  
 
Who advises The Guru?
 
Who assists The Good Samaritan?
 
I think we're about to find out pretty soon-- at least until I can get my
Lapdog running again (and one of the diagnostic programs to troubleshoot my
li'l pony):
 
Meanwhile, I NEED HELP!  With my laptop in pieces all over the bench, I
can't run DIACOM or DATALINK to give me clues about the usual suspects:
 
Clean-livin' doesn't always pay off if my holidaze so far are any
indication.  I spent Christmas Eve on a carlift taking apart my right-front
axle-- again!-- after being assured by our local "Gear-Guru" (who fully
rebuilt that differential less than 6 months before I started hearing that
same CLUNKING on left turns again) that all I needed was a new cir-clip (GM
#14041989) to keep the axle from popping-out of the side-gear in the
differential.  HAH!  More bad advice and I ended up taking a cab home....
More about that Horror Show in a later mailing.
 
Meanwhile, we got our first technical freeze down here in what was becoming
tropical San Antone on Nov. 17th and our first hard-freeze, appropriately,
on Dec. 7th, and somewhere in between those times ol' Syclone #773 began
throwing fits during start-up and for the first 5 or 6 minutes until the
water jacket hits and stays at 180° or so.  I'm stumped for the first time
in a decade or more!  Here's what happens:
 
Since the new Walbro fuel-pump went in a few months ago, cranking times are
way down... engine catches pretty quick, but now it won't stay lit and
"choke" with the new IAC, which went in along with a new TPS and
remote-adjustable FPR about a month before the new Walbro.  Now, I have to
feather the pedal once the ignition gets going and hold the throttle open a
bit while the IAC hunts for about a dozen cycles making the tach swing about
1200 rpm back and forth until we hit the "sweet spot" and the engine takes
off smoothly and the IAC-hunting stops, at least for a while.  Now, it's
safe to put her in gear and drive away as long as I keep a little positive
bias in the pedal for the next few minutes every time I have to slow down to
an idle or coast speed.  
 
THIS PROBLEM IS WICKEDLY WORSE ON COLD DAYS, where ambient air is in the 40s
or below, which thankfully is rare.  (Ain't this global-warming great!)
However, on a couple of occasions when I did have to drive in the 30s-- and
even after reaching full-warm-up temperature-- the engine starts cutting out
seriously as the SES light comes on!  Now, we're talking some MAJOR pumping
of the pedal to keep things lit and if I can get on a clear piece of road
and cruise a spell at 35 mph or better the problem goes away completely,
until I shutdown and the engine gets cold again.  I barely even recognize
that SES light... hardly ever see it.  Driving on warmer days never sees a
recurrence of that mid-period cutting-out, and idle is smooth as is the rest
of drivability.  Warm start-ups see a few moments of that IAC-hunting, but
the rpm-sweeps are only on the order of 500rpm and the whole anomaly goes
away in about 30 seconds.  I've NEVER encountered anything like this in my
many years of wrenching!  Now, it's time for some wretching!!  All that ever
gets logged in the way of a trouble-code is 44... not too helpful!
 
Naturally, I replaced the O2 sensor-- no improvement at all!  Everything
described above instinctually told me this was a weird thermal transient in
the injector-drive circuits or else the MAT, CTS or MAP I replaced (for the
hell of it) 3 years ago needed to be switched again.  So I did... one at a
time to see if I could fault-locate the culprit that way.  No dice!  I'm
running out of hardware to replace!  I've even tried setting that 10-to-1
Chip to different settings, but the same nasty behavior persists-- the
engine's as well as my own!
 
WHO CAN TELL ME WHAT MY PROBLEM(S) IS?  Be nice, now....
 
Dennis O.
 

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