[Syty] Broke & Stumped!

Wed Jan 4 09:03:04 CST 2006

Yep, had all those bases covered before admitting to being STUMPED!

FPR is brand-new; Conrad Cap and Rotor are brand-new, although only one bolt can be secured to the Distributor-- bizarre manufacturing flaw... anyone else ever see this?  I just bought another one yesterday, but that won't fix this problem....

I've taken enough engines through hot pressure-washes to recognize and know how to defeat water in the Distributor as well:  a screwdriver and a spray-can of ether!

Keep trying,

D.O.
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----- Original Message ----- 
From: Ted Metzing 
To: DOlivares 
Sent: Monday, January 02, 2006 9:54 PM
Subject: Re: [Syty] Broke & Stumped!

Hey Dennis, I'm not all that great at diagnosing problems but when you said that you replaced the fuel pump to the Walbro, did you re-adjust the FPR? Maybe too much gas for a cold engine to burn off until warm? Or what about a crack in the distributor cap, letting moisture build up inside it from the previously warm motor (when off) then when cold the moisture is preventing the spark from arcing? Had a problem like that on my Harley with the coil-pack, wouldn't start until all moisture evaporated (warm day or a hot motor). These are just guesses, again not qualified as a problem solver. Good luck.

Ted Metzing
93 TY #0190
06 Trailblazer SS

DOlivares wrote: 
  Thanks... so far, and happy New Year... et pax hominibus boni voluntatis!
  [You know who you are.]

  Unfortunately, I have tried all those diagnostic trees-- even a couple of bushes for good measure!  This episode has been going on for nearly a month.  As I said, I'm running out of hardware to swap-out.  The only things I haven't diddled with is the EST Module in the Distributor and of course the ECM/chip.  

  The reason I haven't fooled with those things is that the misbehavior complained of is SO PREDICTABLE and only afflicts COLD-START-UP conditions, except when it's really cold outside in which case I will get precisely ONE chug-a-lug spasm about 5 minutes into the run-up to full operating temperature... just after everything had been going just fine.  That's the worst of it... as far as I can tell without a scantool... seat-of-the-pants power and smoothness is better than ever, otherwise.  This is no "intermittent."  This is pure predictability!  And my experience with bad chips and modules is that they either fail outright or exhibit sporadic, random upsets... before failing outright.  That's not what's occurring.  Even so, I might drop in my spare EST (Holley Annihilator) just for laughs....

  Keep thinking... what else could it be???  What's the connection to cold/cool ambient temperature?

  D.O. 
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  ----- Original Message ----- 
  From: Jim Sloan 
  To: 'DOlivares' ; syty at syty.org 
  Sent: Monday, January 02, 2006 8:11 AM
  Subject: RE: [Syty] Broke & Stumped!

  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&e-code44.html .

  Just a few ideas, if you haven't already tried them.

  Jim  

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    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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