This is my second string of posts about my 93' Blazer 4x4 that I had had for 24 hours when it ubruptly broke down.... now it's been less than a month and it's broken down again.

I was driving down the freeway idling about 70 mph and my tranny seemed to be chugging a little... I'd try and give it gas and it would jerk a little before finally deciding to accelerate. Then I went to give it gas and the truck would not accelerate at all. I believe the engine was idling when I tried to hit the gas and it didn't do anything when I hit the pedal. It just slowed down to a complete stop and I drove it to the side of the road with full power. Then I turned the vehicle off, put into park and tried to start it again and it turned but wouldn't fire up. Had AAA tow it home and left it overnight. I went out today to check on it and tried to start it twice to no avail, the third time I sat on the key for a few and it fired up. I let it idle for about 20 seconds and pushed the pedal to give it gas and it stalled.

Any ideas? If any of you remember I have so far replaced the gas tank, sending unit, fuel filter, plugs, wires, distributor rotor, and taken off the EGR and cleaned and replaced the gasket on it (the actual fix for my last issue, thanks again for the help on that!)... and now this comes up... I'm at my wits end... any ideas would be welcomed.

 

gimme a little time, im asking a friend of mine to look at this post.

 

Ok heres what he has for ya... :

INTERMITTENT HESITATIONS, LOW POWER, & ROUGH RUNNING ENGINE #67-65-37
- (Jun 3, 1997)
SUBJECT: INTERMITTENT HESITATIONS, LOW POWER, AND ROUGH RUNNING ENGINE
IN COLD TEMPERATURES (REPLACE PCM)

MODELS: 1993-95 CHEVROLET AND GMC, M/L, S/T TRUCKS 1993-94 OLDSMOBILE
BRAVADA WITH 4.3L ENGINE (VIN W - RPO L35) AND HYDRA-MATIC M30
AUTOMATIC TRANSMISSION ONLY

CONDITION:

SOME OWNERS MAY COMMENT ABOUT INTERMITTENT HESITATIONS AT AMBIENT
TEMPERATURES BELOW -10 DEGREES C (14 DEGREES F). THE HESITATIONS MAY
ALSO BE ASSOCIATED WITH LOW POWER OR A ROUGH RUNNING ENGINE. THIS
CONDITION MAY LEAD TO A CLOSED THROTTLE STALL WHEN STOPPED. THIS
CONDITION, IF ENCOUNTERED, WOULD MOST LIKELY OCCUR WITHIN THE FIRST
FEW MINUTES OF ENGINE OPERATION AFTER A COLD OVERNIGHT SOAK. IF THE
LOW POWER CONDITION WERE ENCOUNTERED, THE ENGINE WOULD RUN NORMALLY
AFTER ONE VEHICLE IGNITION CYCLE (OFF/START/RUN).

CAUSE:

UNDER CERTAIN CONDITIONS A HIGH FREQUENCY TRANSIENT VOLTAGE SPIKE BACK
FEEDS INTO THE ENGINE CONTROLLER (PCM) AND CAUSES IT TO RESET. PCM
RESETS WOULD MANIFEST THEMSELVES AS A BUMP OR HESITATION. INFREQUENTLY
THESE RESETS LEAD TO AN INCORRECT FUEL/SPARK RUN MODE WHICH IS
ASSOCIATED WITH THE LOW POWER CONDITION.

CORRECTION:

REPLACE THE PCM WITH A NEW PCM. CHOOSE THE APPROPRIATE PCM FROM THE LIST BELOW.

YEAR MODEL PCM PART NUMBER 1993 M/L AND S/T 16245357 1994-95 M/L AND
S/T 16245358

IN ADDITION TO REPLACING THE PCM, THE ASSOCIATED MEMCAL MUST ALSO BE
REPLACED. CHOOSE THE APPROPRIATE MEMCAL FROM THE LISTED TABLES.

IMPORTANT: THE SERVICE MEMCAL IS COMMON WITH AN EGR SERVICE MEMCAL,
AND SOME VEHICLES MAY ALREADY HAVE THE CORRECT SERVICE MEMCAL.

1993 4.3L (L35) MEMCAL LISTING NEW NEW PROM ID EMISSION NEW MEMCAL
BROADCAST CODE (SCAN BODY STYLE TYPE AXLE PART NUMBER (PROM LABEL)
TOOL)

M-VAN NA5/NA6 GU6(3.42) 16239362 BUZJ 9331 GT4(3.73)

M-VAN NB2 GU6(3.42) 16239338 BUZF 9311 GT4(3.73)

L-VAN NA5/NA6 GU6(3.42) 16239347 BUZH 9321 GT4(3.73)

L-VAN NB2 GU6(3.42) 16239323 BUZD 9301 GT4(3.73)

S/T PICKUP, NA5/NA6 GU4(3.08) 16239400 BUZM 9361 S/T UTILITY GU6(3.42) GT4(3.73)

T PICKUP, NB2 GU4(3.08) 16239376 BUZK 9341 S/T UTILITY GU6(3.42) GT4(3.73)

S PICKUP NB2 GU4(3.08) 16239397 BUZL 9351 GU6(3.42)

1994 4.3L (L35) MEMCAL LISTING

NEW BROADCAST NEW EMISSION NEW MEMCAL CODE PROM ID BODY STYLE TYPE
AXLE PART NUMBER (PROM LABEL) (SCAN TOOL)

M-VAN NA5/NA6 GU6(3.42) 16239423 BUZY 9355 GU4(3.73)

M-VAN NB6 GU6(3.42) 16239408 BUZT 9315 GU4(3.73)

L-VAN NA5/NA6 GU6(3.42) 16239410 BUZU 9325 GT4(3.73)

L-VAN NB6 GU6(3.42) 16239412 BUZW 9335 GT4(3.73)

S/T PICKUP NA5/NA6 GU4(3.08) 16239406 BUZS 9305 NB2 GU6(3.42) GT4(3.73)

S/T UTILITY L35(NO GU4(3.08) 16239420 BUZX 9345 CTF) GU6(3.42)
NA5/NA6/NB6 GT4(3.73)

S/T UTILITY L35(WITH GU6(3.42) 16239403 BUZR 9295 CTF) GT4(3.73) NF2/NB6

1995 4.3L (L35) MEMCAL LISTING

NEW BROADCAST NEW EMISSION NEW MEMCAL CODE PROM ID BODY STYLE TYPE
AXLE PART NUMBER (PROM LABEL) (SCAN TOOL)

S/T UTILITY NF2/NB6 ALL 16239464 BWAK 9445

M-VAN NF2/NB6 GU5(3.23) 16239462 BWAJ 9435 GU6(3.42) GT4(3.73)

M-VAN VD1 GU6(3.42) 16239457 BWAF 9415 GT4(3.73)

L-VAN NF2/NB6 GU6(3.42) 16239459 BWAH 9425 GT4(3.73)

L-VAN VD1 GU6(3.42) 16239444 BWAD 9405 GT4(3.73)

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION: J-6360 LABOR TIME: 1993 M/L 0.6 HRS. S/T 0.8 HRS. ALL
1994 M/L 0.7 HRS. S/T 0.7 HRS. UTILITY 1994 S/T 1.2 HRS. PICKUP 1995
M/L 0.7 HRS. S/T 1.2 HRS. ALL

FIGURES: 0 ATTACHMENTS: 0

GENERAL MOTORS BULLETINS ARE INTENDED FOR USE BY PROFESSIONAL
TECHNICIANS, NOT A "DO-IT-YOURSELFER". THEY ARE WRITTEN TO INFORM
THOSE TECHNICIANS OF CONDITIONS THAT MAY OCCUR ON SOME VEHICLES, OR TO
PROVIDE INFORMATION THAT COULD ASSIS

 

AND.....
ENG. MISS, HESITATION & ROUGH PIERCED SECONDARY IGNITION #93-6D-102 -
(Dec 1, 1992)
SUBJECT: ENGINE MISS HESITATION OR ROUGHNESS DUE TO PIERCED SECONDARY
IGNITION COMPONENTS

VEHICLES AFFECTED: 1980-1993 ALL MODELS

THIS BULLETIN SUPERSEDES AND REPLACES CORPORATE BULLETIN REFERENCE
NUMBER 716404." THIS BULLETIN IS BEING REVISED TO INCLUDE 1989-1993
MODEL YEARS.

During the diagnosis procedure for an engine miss, hesitation or
roughness, a spark plug or spark plug wire condition may be suspected.
Several types of commercial or homemade diagnostic equipment required
the secondary ignition boots or wire to be pierced. This is normally
done to check for spark plug firing or to perform a cylinder balance
test. Similarly, the use of pliers or other such tools to disengage a
spark plug boot may pierce or damage the boot or wire. Secondary
ignition components should not be pierced for any reason.

o Piercing a spark plug wire and/or distributor boot may create a
condition that will not be immediately apparent. Over time, the hole
in the pierced boot may allow a ground path to develop creating a plug
misfire condition. Heavily moisture laden air in the vicinity of the
pierced boot may accelerate this effect.

o Piercing a secondary ignition wire creates a gap in the wire's
conductive core. This gap is a point of high resistance. The current
flow in the wire will increase to compensate for the higher wire
resistance. Over time, the wire may fail creating a plug misfire
condition. The time required for the condition to appear depends upon
the extent of damage to the conductive core.

o To help prevent future condition that are spark plug wire related,
do not pierce or otherwise damage any secondary ignition component.
Only use diagnostic equipment containing an inductive pick-up to check
for spark plug firing or to perform cylinder balance tests. When
disengaging a spark plug boot from the spark plug, twist the flanged
boot 1/2 turn then pull on the boot only to remove the wire.

** BULLETIN REFERENCES: ---------------------- Corporate Ref. 716404

General Motors of Canada 87-6-110 Chevrolet Division 87-121 Pontiac
Division 87-6G-34 Oldsmobile Division 37#10-03 Cadillac Division
T-87-102

General Motors bulletins are intended for use by professional
technicians, not a "do-it-yourselfer". They are written to inform
those technicians of conditions that may occur on some vehicles, or to
provide information that could assist in the proper service of a
vehicle. Properly trained technicians have the equipment, tools,
safety instructions and know-how to do a job properly and safely. If a
condition is described, do not assume that the bulletin applies to
your vehicle, or that your vehicle will have that condition. See a
General Motors dealer servicing your brand of General Motors vehicle
for information on whether your vehicle may benefit from the
information.



GM bulletins are intended for use by professional technicians, NOT a
"do-it-yourselfer". They are written to inform these technicians of
conditions that may occur on some vehicles, or to provide information
that could assist in the proper service of a vehicle. Properly
trained technicians have the equipment, tools, safety instructions,
and know-how to do a job properly and safely. If a condition is
described, DO NOT assume that the bulletin applies to your vehicle, or
that your vehicle will have that condition. See your GM dealer for
information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


(c) Copyright General Motors Corporation. All Rights Reserved.

 

when you replaced the gas tank did you replace the fuel pump?

 

No I did not, however I can hear it suck in the gas when I turn the key, could it still be malfunctioning? PLEASE tell me I don't have to take the friggin' tank off again!!!

 

can't hurt to check the fuel pressure.

you really should've replaced the fuel pump when you replaced the gas tank. yes, the pump could still be malfunctioning even if it primes when you turn the key. the pump might've been damaged when the gas tank was leaking. fuel cools the pump, and fuel pumps don't like pumping air.