hpdi---no idle
 

200 hpdi won;t idle. revs up good in neutral and if i jam it in gear and run it over 900 rpm it runs great. just won't idle, dies as soon as in bring it down under 900 rpm. changed the water seperator and the paper filter in the bowl. just went through the screens and injectors a couple months ago. thinking the tps or bad plugs, will try that in a couple days. any ideas?

Could also be carbon build up on the oxygen sensor. Buy a new gasket for it,take the cover off and clean any carbon off.

x2

You can also check to see if you're getting 50psi on your VST. Grab a fuel pressure gauge from your local automotive shop and tap into the inspection outlet on top of the tank. The gauge should read a constant 50psi at all RPMs. If it's reads low, you could have a clog in the VST filter. If you've ran ethanol fuel through that engine, it builds up a white grime that clogs the little screen at the bottom of the tank.

Try this if the O2 sensor isn't your culprit.

vst tank is good. i'm looking for the oxy sensor now. where is it? thanks for the help.

Look for this black box on the driver's side.

oxy sensor done(not very dirty) no difference, pulled and insp all plugs--all good. still haven't checked the TPS or injectors. prepping for a colonoscopy tomorrow, won't fool with boat again till sunday or monday. thanks for the help.