Ok Gm Tech

[jimmy_chick93]

well to start im new here

name is katie

own a 1993 gmc jimmy

4.3 votec motor

love the truck until recently i have been runnning into some issues with it

 

started out running rough bogging kinda

then i would give it throttle and it would clear it out

changed the filter twice first time it was poopty

then went to the tank tank had poop in it cleaned the tank

checked for pressure had 60 psi at rail

great

but now it had been getting worse and once the engine warmed up it would die and not start until warm again

no codes no sensors maulfunctionin

cannot for the life of me figure this out

a friend of mine also a gm tech cannot figure it out either

sent him all the voltage readings from the scanner and everything seemed to be running fine

although was not able to check it when it died

as i did not have the tool with me at that time..

ANY HELP could be greatly appriciated

-katie

[Genuinefine409]

A friend of mine had a 93 4.3 vortec in a Jimmy and it had similar problems and shoed no codes. It had alomst no power at times. His turned out to be the Catalytic converter was clogged.

[GMTRUCKTECH]

poop in the tank! thats a first for me anyways these trucks are well know for there injector unit leaking fuel into the intake and major egr valve problems. since you had poop in the tank i would start off with flushing the tank replace the fuel pump and sending unit, flush the fuel lines, replace the fuel filter again, and replace the injector unit and egr valve. for the stall condition try a ignition module cuz you said it stalls when warm and restarts once cooled so that sounds like a ignition module. while you are there you may want to look at your ignition system you are proberly do for a major tune up. if you brought your vec into my dealer this is the estimate you would get. nobody wants to work on a 93 jimmy with a 4.3 cuz of all the issues they have. do it all or do nothing! if you try to cut back and rig stuff you will marry yourself to the vec. this is of course a tech side of view and without actually seeing the vec. good luck

[jimmy_chick93]

ok well

already replaced the module

didnt help fuel pump is giving out 60 psi at the rail

pump is good

regulator inside isnt the issue as i have no black smoke

fuel tank has been drained and cleaned crap was from another gas station because the tank is brand new and no other possible way for the crap to get in there.. just small poop but has been removed

as far as replacing the lines there is no point in doing so because it had been bled from the rail with a pressure tester..

so

the only thing i am left with is a clogged catalytic converter

my egr is running at correct volts nothing wrong

i may be a chick but i am a damning good diagnoser

and have run all the necessary tests

catalytic converter is about all i can think of left other than wiring

because of the whole open loop closed loop thing

but thanks for the input

-katie

[GMTRUCKTECH]

OK, NOT TO INSULT YOU BUT, YOU HAVE NO IDEA WHAT YOUR TALKING ABOUT. YOU ARE THE TYPE OF CUSTOMER THAT JUST WILL NOT LISTEN TO REASON. JUST BECAUSE YOU TESTED IT WITH YOUR HOW TO MANUAL OR DID SOME SORT OF REPAIR TO THE VEC IT MUST BE RIGHT, WELL GUESS WHAT, YOUR TRUCK WILL NEVER RUN RIGHT IF YOU CONTINUE TO WORK ON IT THAT WAY. IF YOU ARE THE GREAT DIAGNOISER YOU CLAIM TO BE HERE IS A REAL DOCUMENT FROM GM THAT IF YOUR FOLLOW IT WORD FOR WORD YOU MAY JUST FIX YOUR TRUCK. GOOD LUCK

 

SUPPLEMENTAL DIAGNOSTICS FOR CENTRAL MULTIPORT FUEL INJECT. #56-63-06 - (Oct 19, 1995)

SUBJECT: SUPPLEMENTAL DIAGNOSTICS FOR CENTRAL MULTIPORT FUEL INJECTION (CMFI) ENGINE HARD OR NO START, MISS OR ROUGH RUNNING (REPLACE FUEL PUMP OR FUEL INJECTOR)

 

MODELS: 1992-95 CHEVROLET AND GMC TRUCK S/T, M/L MODELS 1992-94 OLDSMOBILE BRAVADA WITH 4.3L CPI ENGINE (VIN W - RPO L35)

 

CONDITION:

 

SOME 4.3L CMFI ENGINES MAY BE HARD TO START, WILL NOT START, OR MAY MISS OR RUN ROUGH.

 

CAUSE:

 

THE FUEL PUMP/SYSTEM MAY NOT BE DELIVERING THE REQUIRED FUEL PRESSURE TO THE CMFI INJECTOR (IS THE FUEL FILTER PLUGGED OR DUE FOR REPLACEMENT?) OR, THE CMFI UNIT MAY HAVE A FAULT.

 

CORRECTION:

 

IF THE ENGINE CRANKS BUT DOES NOT START OR IS SLOW TO START, FIRST CHECK FOR SUFFICIENT FUEL IN THE GAS TANK. THEN USING KENT-MOORE TOOL J 34730-2C OR EQUIVALENT CHECK FOR FUEL INJECTOR PULSE. USE J 26792 (ST-125) SPARK TESTER OR EQUIVALENT TO CHECK FOR IGNITION SPARK. IF THE INJECTOR PULSE OR IGNITION SPARK IS NOT PRESENT, THIS BULLETIN MAY NOT APPLY. USE THE APPROPRIATE SERVICE MANUAL PROCEDURE TO DIAGNOSE AND CORRECT AS REQUIRED.

 

IF SUFFICIENT FUEL, SPARK AND INJECTOR PULSE SIGNAL ARE PRESENT, THE FUEL PUMP SHOULD BE CHECKED FOR CURRENT DRAW.

 

VERIFY THAT THE BATTERY CONNECTIONS ARE SOUND AND THAT IT HAS A MINIMUM OF 12 VOLTS. USING THE 10 AMP SCALE OF AN AMMETER, CONNECT ONE LEAD TO THE FUEL PUMP PRIME TERMINAL (SEE APPROPRIATE MANUAL FOR LOCATION) AND THE OTHER END TO THE BATTERY B+ TERMINAL. IF THE AMMETER SHOWS LESS THAN 7 AMPS DRAW, WITH THE FUEL LEVEL IN THE TANK CLEARLY ABOVE THE EMPTY MARK (LOW FUEL LEVEL CAN CAUSE LOW CURRENT DRAW READINGS), THE FUEL PUMP SHOULD BE REPLACED. IF 7 AMPS OR MORE IS INDICATED, DISCONNECT THE AMMETER LEADS AND INSTALL FUEL PRESSURE GAUGE J-34730-1A, FOLLOWING THE APPROPRIATE SERVICE MANUAL PROCEDURE. WHILE WATCHING THE FUEL PRESSURE GAUGE, TURN THE IGNITION SWITCH ON. THE FUEL PUMP WILL RUN FOR TWO SECONDS. THE GAUGE SHOULD INDICATE 380-440 KPA (55-64 PSI). WHEN THE PUMP STOPS AFTER TWO SECONDS, THE PRESSURE MAY DROP SLIGHTLY BUT THEN STABILIZE AND SHOULD NOT BLEED DOWN. IF THE PRESSURE DID NOT BLEED DOWN, SKIP THE NEXT STEP.

 

**IF THE SPECIFIED PRESSURE WAS MET BUT BLEEDS DOWN:**

 

INSTALL TECH 1, RAISE VEHICLE TO GAIN ACCESS TO FUEL FEED LINE FORWARD OF THE IN LINE FUEL FILTER. USING THE TECH 1, COMMAND THE FUEL PUMP ON. THE FUEL PUMP SHOULD RUN FOR TWO SECONDS AND STOP. AFTER THE FUEL PUMP STOPS, IMMEDIATELY PINCH THE FLEXIBLE FUEL LINE USING PINCH OFF PLIERS J 41413-50, PART OF KIT J 41413 (EVAP PRESSURE CART).

 

IF FUEL PRESSURE HOLDS STEADY AFTER PINCHING THE FUEL LINE, REMOVE THE FUEL TANK SENDER AND CHECK THE FUEL PUMP PULSE DAMPER (PULSATOR) FOR DAMAGE TO ITS SEALS. IF THE PULSATOR SEALS ARE INTACT, REPLACE THE FUEL PUMP.

 

IF THE PRESSURE BLEEDS DOWN AFTER PINCHING THE FUEL FEED LINE, INSPECT THE FUEL FEED LINE BETWEEN THE PINCH PLIERS AND THE CMFI UNIT FOR A FUEL LEAK. IF A LEAK IS FOUND, REPAIR OR REPLACE AS NECESSARY. IF NO LEAK IS FOUND, REPLACE THE CMFI UNIT.

 

**IF THE SPECIFIED PRESSURE DID NOT BLEED DOWN AFTER 2 SECONDS:**

 

USING INJECTOR TESTER J 39021 WITH ADAPTER J 34730- 225, ACTIVATE THE INJECTOR WHILE OBSERVING THE PRESSURE GAUGE. IT SHOULD DROP TO BETWEEN 275 AND 296 KPA (39-43 PSI).

 

IMPORTANT: DO NOT ACTIVATE THE INJECTOR MORE THAN TWICE WITHOUT STARTING THE ENGINE. THIS IS TO PREVENT FLOODING THE ENGINE WITH FUEL WHICH CAN CAUSE HARD STARTING.

 

IF A SINGLE ACTIVATION OF THE INJECTOR RESULTED IN THE INDICATED GAUGE PRESSURE FALLING BELOW 275 KPA (39 PSI), REPLACE THE INJECTOR. IF NO DROP IN PRESSURE WAS OBSERVED, REFER TO THE INJECTOR COIL TEST IN THE APPROPRIATE SERVICE MANUAL. THE CORRECT INJECTOR COIL VOLTAGE AND RESISTANCE RANGE HAVE BEEN REVISED (REFERENCE BULLETIN 51-63-02). IT IS 3.3 - 4.8 VOLTS AND 1.9 - 2.1 OHM'S RESISTANCE WHEN MEASURED AT TEMPERATURES BETWEEN 50 DEGREES F AND 95 DEGREES F.

 

IF THE SYSTEM PASSED THE ABOVE TESTS, START THE ENGINE AND OBSERVE THE PRESSURE GAUGE. THE PRESSURE SHOULD BE 5-10 PSI LOWER WITH THE ENGINE AT IDLE SPEED. WHILE OBSERVING THE PRESSURE GAUGE, QUICKLY OPEN AND CLOSE THE THROTTLE. THE PRESSURE SHOULD HAVE APPROACHED THE KEY ON TEST PRESSURE OF 380-440 KPA (55 - 64 PSI). IF IT DID NOT, REPLACE THE CMFI UNIT.

 

TO TEST THE INJECTOR POPPET NOZZLES, REMOVE THE UPPER INTAKE MANIFOLD AND INSTALL INJECTOR POPPET NOZZLE TESTERS J 34730-230 FOLLOWING THE SERVICE MANUAL PROCEDURE.

 

TURN THE IGNITION SWITCH ON. ENERGIZE THE INJECTOR. THIS WILL VERIFY IF EACH POPET NOZZLE OPENED BY CHECKING FOR THE PRESENCE OF FUEL IN EACH TESTER. IF ONE OR MORE OF THE NOZZLES DID NOT OPEN, A MISS WILL RESULT AND THE CMFI UNIT SHOULD BE REPLACED.

 

IF THE SYMPTOM PERSISTS, REPLACE THE FUEL PUMP ONLY IF THE AMP DRAW IS LESS THAN 8 AMPS.

 

WARRANTY INFORMATION

 

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

 

LABOR OPERATION: J5547 - FUEL INJECTOR J5590 - FUEL PUMP USE PUBLISHED LABOR OPERATION TIME.

 

IF ADDITIONAL TIME IS REQUIRED IN FOLLOWING THIS SUPPLEMENTAL PROCEDURE, OTHER HOURS SHOULD BE SUBMITTED FOR ON A NORMAL CLAIM. AUTHORIZATION WILL BE REQUIRED.

 

FIGURES: 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 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.

 

COPYRIGHT 1995 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.

[jimmy_chick93]

HAAA HAHA glad to see you thinking you are king crap

but a GM tech who has been for 25 years happens to be a good friend of mine

worked for tallirico GMC for a number of years has diagnosed my truck

Only thing left in my truck to replace is the cat or the spyder itself and possibly some wiring issues

everything else has been done

What are you talking about "if i diagnose it that way" I hooked up a 900$ snap on scan tool to my truck got all the information of my sensors and fuel pressure as well as spark..

so where is that poor diagnosing?

glad youre not working on my truck

so your suggestoin is to replace every fuel line in my truck new tank new this new that

hahah sounds like you are the typical dealership junkie

thanks for the piss poor help

[jimmy_chick93]

and my symptoms are not that it wont run

fuel pump runs perfect thats one thing about gm pumpss YOU CAN HEAR THEM WORK also had voltage checked on it

fuel pump is out..

my truck starts FINE when its cold

Heats up to temp and boggs and then eventually quits

UNTIL it is cold again....

maybe you need to go back to school for proper diagnosing

if it was the fuel pump it wouldnt start and i wouldnt hear it hummnig (working)

all my sensors are actually brand f**king new so i know they are out

only things left are like i said WIRING

CATALYTIC CONVERTER OR SPYDER

FYI..

[454ss]

i have known the spiders in these to crack when they get brittle and have the symtoms you mention, it probably needs to be replaced

[Wingnut]

OK, NOT TO INSULT YOU BUT, YOU HAVE NO IDEA WHAT YOUR TALKING ABOUT. YOU ARE THE TYPE OF CUSTOMER THAT JUST WILL NOT LISTEN TO REASON. JUST BECAUSE YOU TESTED IT WITH YOUR HOW TO MANUAL OR DID SOME SORT OF REPAIR TO THE VEC IT MUST BE RIGHT, WELL GUESS WHAT, YOUR TRUCK WILL NEVER RUN RIGHT IF YOU CONTINUE TO WORK ON IT THAT WAY. IF YOU ARE THE GREAT DIAGNOISER YOU CLAIM TO BE HERE IS A REAL DOCUMENT FROM GM THAT IF YOUR FOLLOW IT WORD FOR WORD YOU MAY JUST FIX YOUR TRUCK. GOOD LUCK

 

 

.............................

 

Don't come in here and talk to our members like that. EVER.

[Norseman]

i have known the spiders in these to crack when they get brittle and have the symtoms you mention, it probably needs to be replaced

 

 

I agree with 454, check out the the injector system.

[GMTRUCKTECH]

i have known the spiders in these to crack when they get brittle and have the symtoms you mention, it probably needs to be replaced

 

 

OK FIRST OFF I NEVER SAID REPLACE FUEL LINES OR TANK I SAID FLUSH THEM OUT AND YOU DID SAY THE VEC STALLS . SECOND IF I WAS WORKING ON YOUR TRUCK IT WOULD OF BEEN FIXED RIGHT THE FIRST TIME . THIRD YOU ARE ARE ALWAYS GOING TO BE RIGHT IN YOUR MIND BECAUSE YOU DON'T READ VERY WELL AND WON'T LISTEN TO ADVISE. (YOU CAME ON HERE ASKING FOR ADVISE) LIKE I SAID YOU ARE ONLY GOING TO BELIEVE WHAT YOU THINK IS RIGHT BECAUSE YOU KNOW IT ALL. I NEED NOT JUSTIFY MYSELF BECAUSE I KNOW WHO I AM AND I KNOW MY GM TRUCKS VERY WELL. SO GOOD LUCK WITH YOUR JIMMY. I HOPE NOBODY POOPS IN YOUR TANK AGAIN.

[Wingnut]

i have known the spiders in these to crack when they get brittle and have the symtoms you mention, it probably needs to be replaced

 

 

OK FIRST OFF I NEVER SAID REPLACE FUEL LINES OR TANK I SAID FLUSH THEM OUT AND YOU DID SAY THE VEC STALLS . SECOND IF I WAS WORKING ON YOUR TRUCK IT WOULD OF BEEN FIXED RIGHT THE FIRST TIME . THIRD YOU ARE ARE ALWAYS GOING TO BE RIGHT IN YOUR MIND BECAUSE YOU DON'T READ VERY WELL AND WON'T LISTEN TO ADVISE. (YOU CAME ON HERE ASKING FOR ADVISE) LIKE I SAID YOU ARE ONLY GOING TO BELIEVE WHAT YOU THINK IS RIGHT BECAUSE YOU KNOW IT ALL. I NEED NOT JUSTIFY MYSELF BECAUSE I KNOW WHO I AM AND I KNOW MY GM TRUCKS VERY WELL. SO GOOD LUCK WITH YOUR JIMMY. I HOPE NOBODY POOPS IN YOUR TANK AGAIN.

 

 

 

The next time you post...Please refrain from posting in all caps. It's considered yelling, not to mention it's just plain hard to read.

[jimmy_chick93]

spare injector to be installed saturday

we will see what happens

[C & A s Dad]

Welcome to the forum Katie. Nice to have another "Parts Person" here.

[jimmy_chick93]

thank you

its what i love!

im one of those who would rather be in the shop building things than just about anything..

i just wish i could figure this pooper out

i havnt changed out the injector because it had been brand new 3 years ago and i would hope a 300 dollar part would last longer than that,.

but it is the only choice pretty much for me right now

my truck had been in an accident and NEVER acted up prior.. so thats where i thought about the whole wiring thing.. but tracing wires is no fun

so the spare injector will have to be put in and if it STILL doesnt fix the problem i willl then start tracing wires..