Fuel Knock

[Signature620]

I've got a truck with a fuel knock, just like the cold knock they get but only at low fueling. Coasting while just touching the accelerator and at high idle for example. It seems to be much more noticeable in the front bank so I put a spare timing actuator on the front and nothing changed. I'm going to try a spare metering actuator tomorrow but I'm just chasing some ideas and input in the meantime.

Cheers.

[Rawze]

what kind of enigne?

have you done a leak test?

[Signature620]

CM871 E, I'll see what I come up with.

[BenT404]

I have the same issue, done all the tests as per rawze recommendations with no luck. Did you manage to sort it out ? What was the fix.

[Rawze]

some guesses...

> Leaky injector?.

>A weak signal on a cam/crank position sensor?.

>slipped cam?.

>metering or timing actuator that is wearing out?.

> Custom program and it has too much injection timing at idle?.

> A vacuum at the intake manifold at idle/low fueling?.

> damaged cam?

> Tone wheel on the crankshaft has play in it?

> excessive clearances in the crankshaft bearing(s)?.

> Loosing compression due to worn out head/valves?.

> Valve train and/or injector rockers out of adjustment?.

== Take your pick.