MY ISSUE STARTED AT APPROX. 40K MILES. ENGINE WOULD BUCK AT HWY SPEEDS EVERY FEW DAYS. PROBLEM PROGRESSIVELY GOT WORSE WITH MILEAGE. ENGINE MISFIRES CAN BE FELT IN THE VEHICLE AND HEARD IN THE EXHAUST. RANDOM MISFIRES CAN BE CAPTURED WITH TECH 2 SCAN TOOL. NO CODES PRESENT.
WHILE DRIVING AT HWY SPEEDS ENGINE MISSES BADLY AND SHUTS OFF FOR ABOUT A SECOND THEN COMES BACK. THIS IS AN ACTIVE FUEL MANAGEMENT ENGINE. 5.3L (0) ENGINE. 4-SPEED AUTO 4X4. I HAVE DISCONNECTED THE OIL PRESSURE SWITCH SO THE ACTIVE FUEL MANAGEMENT WON'T WORK AS IT BACKFIRES IN THE INTAKE MANIFOLD WHEN IT COMES OUT OF 4-CYL MODE. IT FEELS LIKE IT IS DROPPING THE COILS.
GM HAS A TSB THAT DESCRIBES THIS CONDITION TO THE T. TSB IS FOR A HYBRID VEHICLE THAT'S STATES DON'T REPLACE THE TRANSMISSION FOR THIS CONDITION. IT STATES CHECK THE ENGINE GROUND COMING OFF THE ENGINE BLOCK FOR LOOSE OR POOR CONNECTION AS THIS IS THE MAIN GROUND FOR THE IGNITION COILS. HAVE CLEANED AND TIGHTENED THREE TIMES AS THIS DOESN'T APPEAR TO BE THE ISSUE WITH THIS VEHICLE. ANY HELP OR IDEAS WOULD BE GREATLY APPRECIATED. CHECK ENGINE LIGHT DOES NOT COME ON AT ALL...
MY ISSUE STARTED AT APPROX. 40K MILES. ENGINE WOULD BUCK AT HWY SPEEDS EVERY FEW DAYS. PROBLEM PROGRESSIVELY GOT WORSE WITH MILEAGE. ENGINE MISFIRES CAN BE FELT IN THE VEHICLE AND HEARD IN THE EXHAUST. RANDOM MISFIRES CAN BE CAPTURED WITH TECH 2 SCAN TOOL. NO CODES PRESENT.
WHILE DRIVING AT HWY SPEEDS ENGINE MISSES BADLY AND SHUTS OFF FOR ABOUT A SECOND THEN COMES BACK. THIS IS AN ACTIVE FUEL MANAGEMENT ENGINE. 5.3L (0) ENGINE. 4-SPEED AUTO 4X4. I HAVE DISCONNECTED THE OIL PRESSURE SWITCH SO THE ACTIVE FUEL MANAGEMENT WON'T WORK AS IT BACKFIRES IN THE INTAKE MANIFOLD WHEN IT COMES OUT OF 4-CYL MODE. IT FEELS LIKE IT IS DROPPING THE COILS.
GM HAS A TSB THAT DESCRIBES THIS CONDITION TO THE T. TSB IS FOR A HYBRID VEHICLE THAT'S STATES DON'T REPLACE THE TRANSMISSION FOR THIS CONDITION. IT STATES CHECK THE ENGINE GROUND COMING OFF THE ENGINE BLOCK FOR LOOSE OR POOR CONNECTION AS THIS IS THE MAIN GROUND FOR THE IGNITION COILS. HAVE CLEANED AND TIGHTENED THREE TIMES AS THIS DOESN'T APPEAR TO BE THE ISSUE WITH THIS VEHICLE. ANY HELP OR IDEAS WOULD BE GREATLY APPRECIATED. CHECK ENGINE LIGHT DOES NOT COME ON AT ALL...
- Randy W., Mount Juliet, TN, US