[AT] Any Chevy TBI experts

Steve W. falcon at telenet.net
Sun Nov 6 07:33:48 PST 2005


Cecil,
 The 4.3 has a BIG problem with the EGR system. GM even issued a new
program to control them because of the problem. What generally happens
is that a piece of carbon will break loose inside the exhaust crossover
that feeds the EGR and it gets stuck between the pintle and the seat and
holds it open just enough to cause problems. Been through it enough
times that I finally got fed up and bought a new gasket that has a
screen in it to stop the crud from causing problems. I also used to GM
Top Cylinder Cleaner and knocked most of the carbon out with that. It is
a great way to clean out the crud in the engine. You just trickle it
into the intake with the engine running until the you have used about
2/3 of the can, then dump in the rest to cause it to shut down. Then let
it soak for a while and then start back up and drive it around a bit.
Clears out the carbon from the valves and head. BUT DO NOT USE IT
INDOORS or near any neighbors you like. It will generate enough smoke
that you will think the engine is on fire and burning all the oil. It
also throws a LOT of carbon and soot out the tailpipe so aim it away
from anything you don't want turned black.

Here is the gasket I use on all 4.3s now
http://www.tomco-inc.com/

 top engine cleaner part #1050002 from a GM dealer 1 can will do a 4.3

Steve Williams
Near Cooperstown, New York


----- Original Message ----- 
From: "Cecil Bearden" <crbearden at copper.net>
To: "Antique tractor email discussion group"
<at at lists.antique-tractor.com>
Sent: Sunday, November 06, 2005 7:10 AM
Subject: Re: [AT] Any Chevy TBI experts


> It was the EGR valve....
> I checked it with the OTC 2000, and did not have any codes, and
everything
> looked fine on the data stream.  So, used the old fashioned way.  Pull
off a
> line and see if it made any difference.  Sere enough it was the EGR.
Put
> the line back on and it worked fine.  Must have been stuck or
something...
>
> Had to cahnge the transmission fluid, and found a "string" wound
around the
> left CV joint boot.  Could not cut this string with my knife except
one
> strand at a time.  It looked like horse hair!!!!!!
> Parts house guy said it was a deep sea fishing line that had a fine
cable in
> it.  IN OKLAHOMA???!!!!
>
> Never fails, spent 4 hours putting these on about a year ago...
Can't get
> the new one until noon today.  NAPA is closed, O'Reilleys has it in
their
> warehouse, and Autozone carries the same line of boots, but does not
carry
> that number!!!!!!!!!!!
>
> Crazy
>
> Cecil in Okla
> ----- Original Message ----- 
> From: "ken knierim" <wild1 at cpe-66-1-196-61.az.sprintbbd.net>
> To: "Antique tractor email discussion group"
<at at lists.antique-tractor.com>
> Sent: Saturday, November 05, 2005 2:26 PM
> Subject: Re: [AT] Any Chevy TBI experts
>
>
> > On Sat, 2005-11-05 at 00:06, Cecil Bearden wrote:
> >> This is for my tractor hunting vehicle.....
> >>
> >> I have an 89 chevy 4wd 3/4 auto w/ TBI..    at light load, either
> >> starting
> >> out, or running at 30-40 mph the engine surges.  It drives me nuts.
Has
> >> anyone had this problem or knows how to solve it.  I have looked at
> >> several
> >> statements about this on the internet, and according to what I
read, it
> >> could be a 2 week chore testing everything that it could be.  I do
have a
> >> on-board tester for it, but I have never had any codes show up....
> >>
> >> Cecil in OKla
> >>
> >
> > Try the simple stuff first... cap, rotor, plugs, plug wires... that
> > seems to fix a lot of things. After that, the next most likely
culprit
> > would be the throttle position sensor... those seem to fix all kinds
of
> > troubles on my '88 Camaro 305 TBI.
> >    I also had a really freaky one with the electronic spark control
on
> > my '86 Blazer. There was some noise in the driveline that would show
up
> > coming off a light and it would get picked up by the knock sensor,
> > causing a huge stall and surge as it retarded and advanced the
timing.
> > Replaced the knock sensor, went through about everything, finally
ripped
> > out the knock sensor and went to an old-style distributor (thinking
the
> > noise was rod noise). When I finally tore everything down and
separated
> > the engine from the transmission, I found that the factory hadn't
gotten
> > the flex plate bolts tight. It had come loose and was slotting the
holes
> > in the flex plate. The mechanical noise was getting picked up by the
> > knock sensor and wreaking havoc on driveability, similar to your
> > description. It was carbureted but they may be running similar knock
> > sensors...
> >
> > Oh, 1986 305 V8, Rochester 4 BBL, TH700R4, K-5 Blazer (4X4).
> >
> > Ken in AZ
> >
> > _______________________________________________
> > AT mailing list
> > Remembering Our Friend Cecil Monson 11-4-2005
> > http://www.antique-tractor.com/mailman/listinfo/at
>
> _______________________________________________
> AT mailing list
> Remembering Our Friend Cecil Monson 11-4-2005
> http://www.antique-tractor.com/mailman/listinfo/at
>




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