AFM turning off cylinder 7 all the time.
04-27-2020, 08:51 PM
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AFM turning off cylinder 7 all the time. Hi,
I have a 5.3L LC9 with code p0307. I had a collapsed lifter on #7 and I pulled the heads and replaced all 8 AFM lifters. After reassembly I still have the #7 misfire. I have rolled the engine by hand with the valve cover off and watched the rockers move. I fired it up briefly with the valve cover off and the rockers for #7 don't move. I assume that the AFM system is incorrectly turning off cylinder 7. I then replaced the VLOM with a used one...no luck. Any thoughts on where I could start looking to fix this problem?
Thanks in advance
Ryan
I have a 5.3L LC9 with code p0307. I had a collapsed lifter on #7 and I pulled the heads and replaced all 8 AFM lifters. After reassembly I still have the #7 misfire. I have rolled the engine by hand with the valve cover off and watched the rockers move. I fired it up briefly with the valve cover off and the rockers for #7 don't move. I assume that the AFM system is incorrectly turning off cylinder 7. I then replaced the VLOM with a used one...no luck. Any thoughts on where I could start looking to fix this problem?
Thanks in advance
Ryan
04-27-2020, 09:56 PM
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Look for a blocked oil passage in the valley cover feeding the towers
04-28-2020, 07:42 AM
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By valley cover, you mean VLOM right? I replaced the VLOM with a used one. I feel like it would be unlikely that both VLOM's would have the same issue. I have the intake manifold off right now so I can have a look easily enough. I also have a brand new VLOM that I was planning to send back.
Another thing worth noting. I have the tested the wiring to the VLOM at the VLOM plug for continuity to ground. The Red wire has 6200ohms to ground. That seems odd to me. I would expect none of the wires to have any path to ground until the ECM grounds them.
Another thing worth noting. I have the tested the wiring to the VLOM at the VLOM plug for continuity to ground. The Red wire has 6200ohms to ground. That seems odd to me. I would expect none of the wires to have any path to ground until the ECM grounds them.
05-05-2020, 12:47 AM
#4
Sounds like you may have a short somewhere. 6200 is a lot of ohms to activate the solenoid in the vlom, but it's possible I suppose. If you can de-pin the red wire from the connector at the vlom that would at least identify an electrical vs mechanical problem.
05-05-2020, 08:04 AM
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Thanks for the input. I am suspecting a short in the wiring as well. I have looked for anything obvious but nothing stood out. I will investigate further.
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rpturbo (05-06-2020)
