1986 S10 2.8 BACKFIREING
DOES ANY ONE NO WHY THIS TRUCK IS BACK FIREING OUT THE BACK. PUT EVERY SENSER IN IT NEW FUEL PUMP, COMP.NEW ROTOR CAP, NEW PLUGS,NEW MONDULE,NEW INJECTER,WE HAVE TIMED IT WITH TIMEING LIGHT IT WILL START AN IDLE FOR 2-3 MINUTES THEN IDLES UP AN DOWN UNTIL THREMASATE REACHES 21O THEN SMOOTHS OUT OK. THEN WHEN YOU GO DOWN THE ROAD AN SHLFT GEARS IT BACKFIRES OUT THE BACK REALLY LOUD.DOES ANYONE NO WHAT MAY BE WRONG WITH IT? THANKS DEB.