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Discussion Starter · #1 ·
I have I super annoying problem with a surging Idle, randomly jumps between 600-750 rpm rocks car, no check engine light, replaced all electronics, (air temp sensor, throttle body, map sensor, cam sensor, crank sensor, O2 sensors, PCM,) Compression is 205 even across the cylinders, fuel pressure is in spec, cam lift was measured, cam timing was checked, valve springs checked, No vacuum leaks, was fog tested and smoke pressure tested, But manifold pressure is only at 14 inches for some reason, any help would be appreciated as I'm at a loss as the dealership has no Idea whats wrong or how to fix it and I have taken it to multiple dealerships
 

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The list of parts and diagnostic checks included in your post are the typical fixes for surging. Does the surging occur only when the A/C is On?
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Discussion Starter · #4 ·
the low manifold pressure is what has me, its obvious thats the cause but I have no reason for it to be low
 

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An intake manifold air leak will cause lower than normal manifold vacuum. One or more cylinders not functioning properly will also cause lower than normal manifold vacuum; but they did a compression test and all cylinders checked OK.
The intake manifold has a dual shaft Short Runner Valve (SRV) system. The SRV is bolted to the rear of the intake manifold and can be serviced separately from the manifold. Check the wiring/connector to the SRV to make it's a good connection. The SRV could be erroneously switching between short and long runners .
Check the PCV valve and O-ring. Check all the tubing that connects to the intake manifold for tight fit, cracks, air leaks, etc ...
With the engine running at idle, use a spray bottle with water to spray around the intake manifold and SRV gasket areas. Listen for a change in RPM to locate any area that is leaking.
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I could be wrong but I thought the SRV Intake system was introduced in 2012.

Something I read on the Challenger Talk, same symptoms and it turned out to be the manifold bolts had worked lose and needed tightened down. I know this happens on the 5.7L intake also. Every few months they had to be torqued back to spec.
 

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I could be wrong but I thought the SRV Intake system was introduced in 2012.
The Apache and Eagle engines released in 2009 but the SRV intake was released on different model years for the RAM trucks and Chargers. You're probably correct about 2012 for the Charger. A visual inspection of the rear of your intake manifold will verify whether the SRV control module is attached or not.
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