Archived Knocks and rough idle

[TDC]

I have a 2003 Dodge Dually 4x2 Auto with 347,000 miles. . It has a bad knock and rough idle, but when you drive and punch it the knock will go away. . Code is 0088... Fuel rail pressure to high... One guy tell me FCA and the other tells me pressure relief check valve. . I like the price of the FCA but would like to get this truck fixed. . Can I check anything.....

 

[Missouri Mule]

Could be injector(s)!

But with the code I would say the FCA if the pressure was to high the relief valve should of popped.

Should be a way to check out FCA maybe a continuity test with multi-meter. I would think with engine/key off the readings woud be zero.

 

[MMoroney]

It sounds like your FCA is bad.



I don't think your fuel pressure relief valve is bad. Even if the fuel pressure relief valve was blocked completely, it would not cause a knock at idle.



I have disconnected the FCA on my truck for a few seconds while troubleshooting, and the engine knocks like crazy due to all that fuel pressure.



My vote is for the FCA on this one.



Mike

 

[TDC]

I have both on order... We'll see which one it is... Thanks for the help