Chevrolet Repair/1997 chevy dually 454 vortec
QUESTION: Hi Sir my name is frank. Well my problem is my dually has now started to kinda die on ,me when i put it in gearv n start driving. if i dont give it gas and brake at the same time it just turns off.It has been running pretty good. the last thing i did to my truck was replace the distributor about 6 months ago. changed cap wires n rotor also.I have checked the spark plugs wires n cap n rotor but they are good no fouling or arching wires cap n rotor are still in good shape. What i have noticed is that for some reason it does blow off the hose that goes from the evap canister to the purge selinoid. it has also blow off the hose that sits by the intake manifold that goes to a round plastic diaphram that then goes to each side of the exhaust manifolds that are metal tubes. one more thing that i noticed was that my fuel pump is also now huming kinda loud. it use to be alot quieter before. those are the only things i noticed before it started running like crap and dieing out on me when driving. if you need more in fo just tell me what to check n i will send it to you. you guys are the only people i truely trust for diagnosing any vehical i own. as always thank you n hope to hear from you soon
ANSWER: GOOD MORNING FRANK, WELL THE REASON WHY THE EVAP HOSE IS BLOWING OFF IS MORE THEN LIKELY THE VENT VALVE IN THE SYSTEM IS PARTIALLY PLUGGED OR PLUGGED.THIS VALVE IS USUALLY AROUND THE FUL TANK AREA...THIS WILL NOT CAUSE A STALLING ISSUE..SO THE WAY I HAVE READ THIS IS THAT THE ENGINE IS RUNNING VERY GOOD NO SKIPS OR ANYTHING LIKE THAT ???I AM GOING ON THIS ASSUMPTION...THE ENGINE WILL NOT IDLE OR IDLES VERY LOW CAUSING IT TO STALL IN GEAR , THIS FIRST THING I WOULD DO IS GET YOURSELF SOME CARBURETOR CLEANER TURN THE ENGINE OFF AND REMOVE THE AIR DUCT WORK TO THE THROTTLE BODY..NOW OPEN THE THROTTLE ALL THE WAY AND SPARY THE CLEANER ON THE BACK SIDE OF THE THROTTLE PLATE ALSO USE A SOFT CLOTH TO REMOVE ANY CARBON ON THE BACK SIDE OF THIS PLATE..ONCE IT IS CLEANED PUT THE DUCT WORK BACK TOGETHER AND SEE IF IT IDLES ANY BETTER [[[AFTER DRIVING IT FOR 2 OR 3 MILES.]]]IF NO CHANGE, THIS ENG MAY HAVE A BAD, IAC..SORRY [IDLE AIR CONTROLLER]IS THERE EVER A CHECK ENGINE LIGHT ON ?? IF SO GET THE CODE FOR ME THIS COULD TELL US ALOT..ALSO IF THE CK ENG LIGHT IS NOT ON YOU COULD STILL GET THE PCM SCANNED FOR CODES AND GET BACK TO ME ON THIS.. THE FUEL PUMP MAKING NOISE LIKE THIS IS NOT A VERY GOOD SIGN BUT THIS DOES NOT MEAN THE FUEL PUMP IS GOING TO GO BAD IN THE NEXT 3 DAYS OR SO..A BAD FUEL PUMP DOES ONE OF 2 THINGS..WILL NOT START OR WEAK FUEL PUMP CAUSES A LAG OF POWER ON THE OPEN ROAD AT HIGHER SPEEDS. THIS IS NOT YOUR PROBLEM EITHER..JUST KEEP A EYE ON IT AND THE PROBLEMS I SAID TO LOOK FOR..THIS SHOULD KEEP YOU BUSY FOR A LITTLE BIT.LET ME KNOW HOW THIS GOES AND GET BACK TO ME..GOOD LUCK TOM.....
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QUESTION: Hi ther again. Well my truck finally wont start. this time i checked the obd2 codes even tho my check engine light was not on. So it spit out these codes P0101 P0108 P0121 and P1345. The first three are all emissions codes. What im wondering is what could of set them all off? I know what to check but yiour great knowledge is needed for this. Im stuck here thinking should I replace all of these or What. please qany help would be greatly appriciated thank you once again..
ANSWER: HI FRANK, OK LETS START WITH CODES PO101 TO PO108. THESE CODES ARE ALL FOR MAS AIR FLOW FAULTS. REALLY NOT EMISSION FAULTS LIKE EVAP CODES AND SO ON..101 IS MASS AIR FLOW VOLTAGE INCORRECT,108 IS LOW VOLTAGE,121 TPS SENSOR OUT OF RANGE...I HAVE FOUND MANY OF THESES ENGINE TO HAVE BAD WIRING HARNESSES AROUND THE AREA OF THE THROTTLE BODY AREA..PEEL BACK THE PLASTIC COVER AROUND THE HARNESS AND LOOK VERY CAREFULLY AT THE WIRE GOING TO THE MASS AIR FLOW AND TPS..IF THEY ALL LOOK OK, REMOVE THE MASS AIR FLOW AND GET SOME CLEANER AND SPRAY THE INSIDE OF THE MASS AIR FLOW OUT, MAKE SURE IT IS GOOD AND CLEAN..REINSTALL. HOWEVER I DO NOT FEEL THAT THIS IS THE REASON THAT THE ENG IS NOT STARTING..KEEP READING,,.NOW FOR CODE# PO 1345, YOU SAID YOU PUT A NEW DIST IN THIS 6 MONTHS BACK ??THIS CODE IS FOR CAMSHAFT AND CRANKSHAFT CORRELATION PROBLEMS
THIS MEANS THAT ONE OR THE OTHER IS NOT SEEING THINKS IN THE CORRECT ALIGNMENT..COULD BE THE DISTRIBUTOR IS OFF ON TIMING,LOOSE DIST, JUMPED TIMING CHAIN, BAD TIMING GEARS. WHEN YOU PUT THE DISTRIBUTOR BACK IN THE ENGINE DID YOU USE A SCAN TOOL TO SET THE TIMING ??? IF NOT YOU WILL NEED TO DO SO. BECAUSE THE PCM SETS THE TIMING ON THIS ENGINE, AND YOU NEED TO SET THE TIMING UP THROUGH A SCAN TOOL THAT CAN DO THIS NOT JUST A SCAN TOOL THAT CAN READ CODES..THE SCAN TOOL WILL NEED GM SOFTWARE TO DO THIS..YOU MAY NEED TO TAKE THIS TO A SHOP THAT CAN DO THIS...YOU SAY THE ENG WILL NOT START..HAVE YOU CHECKED FOR SPARK AND FUEL ??? CK THIS OUT AND GET BACK TO ME AFTER YOU HAVE LOOKED INTO THE ABOVE.IF NO SPARK I WOULD BE LOOKING AT HE DIST AGAIN. YOU SAID THE FUEL PUMP WAS GETTING LOUD,MAYBE THE PUMP HAS FAILED. CK FOR FUEL PRESSURE, IF NONE,CK FOR POWER BACK AT THE TANK,IF POWER IS THERE WHEN CRANKING THE ENGINE OVER THE PUMP HAS FAILED.. GOOD LUCK TO YOU,,TOM..
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QUESTION: Hi ther Sir. Well I did check the wirin g harness taped up a few wires . Checked it 3 times till it was all repaired. The next day I go to start my truck and it fired rite up but then died. tryed it again fired rite up but the died once again.So what its doing now is it cranks over starts then dies It wont stay running at all. I rechecked the codes and now I have 2 new ones. They are P0102 and p0122. those are the only ones it is giving now.I hope to hear from you soon as you have been such a great Help to me.( so i turn the key the truck starts but dies instantly it wont stay running) before I couldnt even get it to startv atv all
Thank you once more FRANK
HI FRANK, I WILL ASSUME YOU HAVE RESET THE PCM AFTER REPAIRING THE WIRES..YES..THIS IS WHY YOU KNOW YOU HAVE NEW CODES ?? SO IF THIS IS THE CASE WHAT I WOULD LIKE YOU TO DO NEXT IS REMOVE THE WIRE HARNESS FROM TER MASS AIR FLOW AND SEE IF THE ENG WILL START UP LIKE THIS AND CONTIUNUE TO RUN. IT MAY NOT RUN GREAT,BUT SEE IF IT WILL NOT STALL OUT ANYMORE..IF STALLING IS GONE, THE MASS AIR FLOW IS BAD..REPLACE IT. THE PO102 IS THE MASS AIR FLOW CIRCUIT..THE PO122 IS FOR TPS CIRCUIT FAULT.. [SORRRY, THROTTLE POSITION SENSOR.]THIS LAST CODE MAY SET BECAUSE OF THE MASS AIR FLOW FAULT..ONE LAST THING,ARE YOU SURE THIS DOES NOT DIE OUT BECAUSE OF LACK OF FUEL PRESSURE ??? HAVE YOU EVER PUT A PRESSURE GAUGE ON IT ??? IF YOU DO NOT HAVE A GAUGE, YOU COULD REMOVE THE SHRADER VALVE ON THE FUEL PRESSURE TEST PORT ON THE FUEL RAIL. THIS WILL LOOK LIKE A TIRE VALVE STEM CAP,REMOVE THE CAP AND HAVE SOMEONE CRANK THE ENGINE OVER WHILE YOU PUSH DOWN ON THE VALVE INSIDE AND SEE IF YOU GET GAS THE ENTIRE TIME THE ENGINE IS CRANKING OVER NOT JUST THE FIRST 2 TO 3 SECONDS. TRY THIS 25 TO 30 SECONDS DO NOT RELEASE THE KEY..IF FUEL IS PRESENT THE ENTIRE TIME MORE THEN LIKELY THE FUEL PUMP IS GOOD. IF NOT FUEL PUMP IS NO GOOD. PRESSURE FOR THE FIRST 2 TO 3 SECONDS IS CALLED RESIDUAL PRESSURE. THIS IS NO GOOD AND WILL FOOL YOU ALL THE TIME. YOU ARE ALSO SURE THE THE WIRING HARNESS TO THE MASS AIR AND TPS ARE ALL OK. NO BROKEN WIRES HERE...LET ME KNOW HOW THIS GOES AND GET BACK TO ME..TOM....