I have a non-US 740 with a k-jet FI (B230E). I'm posting here as from my search it's evident this is the best forum to seek advice.

I've posted before regarding my base idle problem. To summarize my base idle won't stay put at 900 rpm as per spec. It would gradually over a few months drop to around 700. At that lowish idle the car would shake.
A poster (Colin) suggested that I readjust the base idle again by checking the throttle stop plate and TPS. Strangely enough it was off considering I cleaned the throttle body and adjusted everything good a few months back. Idle went back to 900.

That was 4 months ago and now the same problem has returned. Idle now is 700 with nearly 500 in drive. I've rechecked the base idle adjustement and everything is ok. All hoses from air box to intake are new except for 2 hoses which I did check again to confirm they had no tear/hole. For an unrelated problem the air mixture was checked 5 months ago which revealed a very lean mixture (almost 0 CO IIRC). That was adjusted. IF it's relevant, I've cleaned the oil breather box.

From my search I gather the injectors can cause funny idle problems. I suspect it's either that or leaky intake manifold gasket as the source of my problem. I've checked for both by spraying STP fuel intake cleaner and I didn't get any change in the idle.

Has anyone else had the same problem before on their k-jet? I'm at a dead end now. Should I just go ahead and change the injectors and their seal? And the intake manifold gasket too? Car mileage is a relatively low 240k km.

Thanks! And sorry for the long post!

Aslan
Malaysia