Engine not idling right

[jondee86]

Jezza_hr Wrote:- Adjusted the fuel trims and timing in the MAP screen with little to no
noticeable changes apart from a raise in engine speed

By how much (%) did you trim the fuel ?

- There is no real change in the engine operation when removing any
singular HT lead

Would tend to indicate auto-ignition is taking place.

- There is also no noticeable change in the idle when removing the brake
booster line, but the engine drops out when removing the vacuum line to
the FPR

If you remove the hose between the check valve and the booster, it has
no effect on the engine. If you remove it between the check valve and
the manifold, it should jump your idle substantially.

Taking the hose off the FPR will cause the rail pressure to rise, and the
engine will run even richer.

- The engine still wants to keep running after switching it off, popping out
of the intake as it splutters to a stop

Tends to indicate that you have a lot of unburned fuel in the manifold and
in the combustion chambers, as both ignition and injection should stop
immediately you turn the key OFF.

- The spark plugs do have a fair amount of carbon deposits on them,
leading me to believe they are getting sufficient amounts of fuel. Plus the
distinct smell of fuel coming out of the exhaust.

Tends to indicate a rich condition.

I'd be inclined to experiment with taking more fuel out with the master
trim control. Try 20% or 30%... see if it cleans up.

Cheers... jondee86