Our Truck 4-2012 4/24/2012, P.J.C. ~ REV.

1998 4.3L, "W" (190 HP) S-10, Blazer , 4x4 (Four Door LS)
18 Gallon fuel Tank
166000 Miles

Parts Installed at 166K;

Spark Plugs
Air Filter
Fuel Filter
PCV Valve
Vacume hoses as posb..
O2 Sensors (Heated 4 wire) Both Up-Stream( Bosh brand)

MAF (un-nessary part, I got talked into)

Intake Manafold Gasket (Lower done only)


Codes Found at 166K; (first PO is Gm, 2nd is what test guy told me)

PO404 EGR Valve Pintle Position / 2nd ~~ EGR out of range

PO420 TWC System Low Efficiency-Bank 1 / 2nd Cat Effecitnty below threshold

PO101 MAF System Performance

PO-xxx HO2S ~~ Bank 1, Sensor 1 (Code removed by test guy)


Work Done at 166K;

Pressure Wash off Motor top and bottom, as needed.

Cleaned sludge from Intake ports in manafold and Cylinder Head ports,
Used o2 safe carb cleaner & Sea-Foam can added to 1/2 tank of fuel,
Found and removed plastic tubeing type assamble plug left in at OE manufacture
(truck ran 166K with this in head from Factory)


when i pulled and marked distribtor for base timming
the drive gear was worn bad, i hear thats sorta normal for a high millage 4.3L
But Can this retard timing so much as to make timing probs?

all above parts had been installed and the driveabilaty probs are still there..
It needed lots of maint. and I do feel only part not needed so far is the MAF i got talked into,,

I also have checked and replaced vacume hoses as a mesure to head off issues

Seems to have low vacume like 15hg
and as i give it throttle it dont look like a converter
but on my vac guadge it at the retarded timing band on gadge fpor what its worth..

I have rechecked all the work i have done and dont want to start to shovle money at this pig, most i had done was maint so far.


Complant;

Truck runs and starts okay. (Other then what i feel is lack of power)
after a drive of about 50-100 miles ( far from home )
At Full operating temp
it starts to Bog bad and slow down to a stop
loud ping and have to play with pettle to floor and let up as anything to keep it running to get home,, (Labors bad, ping, bucks and surges,)
we saw Serious red hot pipes of manafoulds and it still did not re-set a CEL??
shut it off before it killed more then it has and posb fire.

sorta feels like its running out of fuel and restarting at times
has no funny smoke out of ext?

where to go next? and what I hope to try to do;;

Check and clean EGR

install and leave fuel pressure gadge on it and wait for it to do its thing
its got 60-55PSI KOEO & about 50-55 KOER?
(Pumps less then a year old and is a delphi brand)

Try to beg, browr an Cat presure tester for back pressure,,
or pull o2 sensor/s to see if it gets better
or just try to drop cat and drive it..
(but would seem like that would be hapin all the time, but would be the dog part of this prob)


all this works being done on my stone driveway so sorta
a real bear, with weather here.
Please if you might have some other Ideas for me
post here so i might try to end this nightmare. LOL

Thank-you all in advance

Patrick
AKA; Sparkz

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Up-Date; 4/25/2012


I Pulled the o2 Sensor on Bank #2
and drove truck about 1/4 - 1/2 mile
Brake-Tourqued (Loaded converter and relesed)
it's seemed to have not a ton of diff from when o2 was installed

(think it might could use less restriction but sure not all in cat?
I will try to look deeper into that for sure,,
just cant spend 300 bux for un-nessary parts)

Other tests I could do so far;

Used can of o2 safe Carb. cleaner to look for posb
vacume leaks that might lean out motor
checked ign wires yet again for burns and or damage/s
and any white flashed leaks wire to wire and to just about everything around them,
wires are on my "Wish list" but they are like most things 166K old,
but do not have bad spots i can see (Both dry and wet in the dark)
so
Hooked up the Vacume gaudge and Fuel Pressure

Idle,,
53 - 54 PSI (sm bounce in nettle)
18-1/2 Inches vacume

At a Punch (Snaped throttle and return to Idle),,
62 - 51 PSI smooth rise and return
0 - 24" Inches Vacume

2500 RPM (Sliped a Quarter in TB Stop to hold) lol
52 PSI Solid reading
Vacume solid at 22 Inches Vacume


Motor OFF,,
Fuel Pressure held 60 PSI for over 10 minuits
and was still 50 PSI 30 minuits later

>>>>>>>>>>>>>>>>>

I am waiting for it to cool down right now
so i might reinstall o2 sensor
and have a 2nd look at vacume,, in an atempt to
confirm or rule out converter issues..

also found a alum dist on web RockAuto Auto Parts for 100 bux with brass cap & Rotor
as my dist now has a broken ear from a shop i had to pay on the road with no tools, too bad i didnt know that back then,,
but to complete the full tune-up its gettin the cap & Rotor and il replace the ign cables as there 166K old too..
Just eattin me alive over here lol


Please if you might had seen this or know of other things i might or should be looking at, Please advise (as trucks making me nuckin futz)

Thank-you in advance
for any help / ideas commonts you may give or have

Patrick
AKA; Sparkz

 

Sounds to me like your catalytic converter is plugged. Let it get up to temperature at night and look at the cat and see if it is glowing red. if so then it is clogged and you need a new one. Because your other pipes are red hot then that makes me think even more that its the cat. Clogged cat will also cause the lack of power and stalling (if its bad enough)

 

yeha my thinking is a cat, but I hoped to be sure and to find whatever killed it,, I am going to try to punch it out and then try to locate whatever at issue hope to fix that and install a new cat,, er thATS the plan for now, if i can get a break in weather,, Rain like a bear here.. Thanks for the input

Sparkz

 

Hard to believe it's not throwing code of any kind. If the pipes ahead of cat are glowing that is serious spark timing retard.
I was trying to reconcile that with ping {too far advance} and all I can figure is the PCM trying to get timing right and the ign module flaky.. sometimes no advance {limp-in mode} and sometimes works, too far advanced.