What brand spark plugs did you use ? And plug wireshave a 2000 Silverado with a 5.3 and have a p0300. cylinders 1 & 8 are dead misfires at idle but when you get the rpms up the misfire moves and starts jumping around to all cylinders. have new plug wires and plugs have also had the injectors test and cleaned. tested wires from ecm to each injectors wire and they are good. have swap coils from cylinders. 1&8 are still dead till you get high in rpms then it moves to multiple cylinders. did a crankshaft and camshaft sensors and timing gear and chain. and i still have the dead cylinders on 1&8 till i get high in rpms then it moves to other cylinders and did a compression test on the motor have 150psi across all cylinders. pretty stumped any info or recommendations would be extremely helpful tired of throwing parts at it and nothing working.
p0300 2000 chevy 5.3
have a 2000 Silverado with a 5.3 and have a p0300. cylinders 1 & 8 are dead misfires at idle but when you get the rpms up the misfire moves and starts jumping around to all cylinders. have new plug wires and plugs have also had the injectors test and cleaned. tested wires from ecm to each injectors wire and they are good. have swap coils from cylinders. 1&8 are still dead till you get high in rpms then it moves to multiple cylinders. did a crankshaft and camshaft sensors and timing gear and chain. and i still have the dead cylinders on 1&8 till i get high in rpms then it moves to other cylinders and did a compression test on the motor have 150psi across all cylinders. pretty stumped any info or recommendations would be extremely helpful tired of throwing parts at it and nothing working.
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What brand spark plugs did you use ? And plug wires
DO NOT use a test light to check injectors. Use what is called Noid light . And will tell you if the is firing an injector .Questions from me, I know very little about FI rails. Is there a regulator to open up to send excess fuel pressure back to the gas tank? During idle, can gas be squirted into the air intake past the MAF sensor? Can a test light or voltmeter be placed at the fuel injector to know that the injectors are working at idle Or with a finger, feel the injector that it is operating?
An Oscilloscope could tell you . Back in the day they were called tune up machine. It tell you how much voltage to each plug along with duration,also tell whether a cylinder is rich or lean.no vacuum leak and used ac Delco plugs
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