#4&6 cylinder not operating. Coils,plugs,injectors,& connectors test ok.
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Initially sounds like #4 & #6 cylinders fire on start up after that its like they aren't receiving fuel. The injectors tested ok and we visually checked them with the intake manifold off and they do receive an initial spray of fuel. The coils & plugs tested ok with a strong spark. When we disconnect cylinder #5 we notice an immediate drop in the engine and a backfire from the fuel. When we do this on 4 & 6 there is no change in the engine,no backfire and the plugs are not wet. We've reset the PCM with no change, the fuel filter is new, all plugs are new, all coils were checked, all injectors were checked, all connectors were checked. as far as I can tell the way the wiring harness is made you can't misconnect #4 & #6 connectors.
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Compression on 4,5 & 6 is identical 140 psi. Unplugged 4 & 6 turned over engine and checked plugs they were wet so initially they get fuel. We observed each injector spray in fuel when we had the intake manifold off which I take is essentially the same as a noid test as there would have to be a pulse for them to work. It seems however they do not receive any fuel after the initial dose because when the vehicle is running you can disconnect and there is no change,the plugs are dry and there is no backfire. Could it be the PCM is there a difference between start & run ?
Compression on 4,5 & 6 is identical 140 psi. Unplugged 4 & 6 turned over engine and checked plugs they were wet so initially they get fuel. We observed each injector spray in fuel when we had the intake manifold off which I take is essentially the same as a noid test as there would have to be a pulse for them to work. It seems however they do not receive any fuel after the initial dose because when the vehicle is running you can disconnect and there is no change,the plugs are dry and there is no backfire. Could it be the PCM is there a difference between start & run ?