2001 hpdi plugs fouling

[wildcater]

replace powerhead and fuel injectors, engine starts and runs for 1 minute, than stalls, pulled plugs and they were wet. cleaned them and engine started and ran 1 min. pulled them again and they were wet, spun engine over and it had a real good mist. have rebuilt 6 hpdi and have never had this problem.

[Tucker]

What motor you talking about wild?

[wildcater]

plug fouling 200 2001 hpdi

the motor is a 200, 2001 hpdi, ched vst tank for flooding and also mech fuel pumps for leaking in to block

[99yam40]

Model #s are always the best way to let everyone know what motor you are speaking about.

What took out the last power head and have you fixed the cause ?

Post all the trouble shooting with the results you have done so far like fuel pressures and any other stuff you have tested with the proper test equipment as the service manual states.

[rodbolt17]

if the VST needle leaks it floods #6.
if a lift pump leaks it floods that cylinder.
nothing the medium or high pressure pump can do to flood it.
NOTHING.
unless your a machinist that simply needs an alternator.
I would look for a leaking VST needle,a blown lift pump or a leaking injector.

[wildcater]

fouling plug lz200 hpdi

motor is lz200 hpdi,2001, checked vst it is not leaking, checked mech lift pumps not leakinf, all cylinders are fouling and heavy mist coming from all cyl., fuel pressure between 40 and 60 psi at cranking speed. itried to hook up my laptop with new soft ware and cable but cant get com with engine, i think i know why, my lap top is new windows 7 and every one been telling me it wont work. going to load soft ware in my wife xp lap top and try that.

[rodbolt17]

are you quite sure what HPDI stands for?
are you sure how it works ?

[wildcater]

motor has a belt driven high pressure pump

[rodbolt17]

so you really dont understand how it works?
motor has 2 lift pumps,one medium pressure electric pump and one belt driven high pressure pump.
once past the VST fuel can only enter the cylinders via the injectors, period.
if the lift pump diaphrams leak it floods one bank,if the VST needle leaks it can flood the lower two cylinders if the HP pump leaks its an external leak.
you need to monitor high pressure fuel rail but I suspect you have an ign issue.

[wildcater]

what took out powerhead

stbd side thermostat was frozen that side overheated and piston let go engine has 3000. hr on it this is the second powerhead and it has 2500 hrs on it. replaced it with new powerhead and new injectors. this boat is used by a charter capt. puts lots of hr on his engines.

[wildcater]

thanks rebolt, i do know how this system works, like i said im going try to hook up my other laptop and also i will ck high pressure pump, any ideas on ignition, i am working off site so i have to keep coming back to shop to ck forum. it still bothering me why such a heavy mist coming out all cylinders, i did check spark with a spark checker and all cylinders had good spark. thank again, im at end of ideas, but i will keep trying

[Tucker]

Woh, 3000 hrs! I always thought the 200 HPDI was a killer motor based on everything I read. About as high-maintenance as a big-titted blond, but definately a good motor. Wonder how far it would have went if you didn't have the stat problem.

[wildcater]

update on todays work

put another set of plugs in the motor, started up and ran with a little throttle opening, took boat to water and wouldnt stay running with doing any thing, so i disconnected the injectors and just fed the motor starting fluid and got to run in water on trailer. this the longest i have been able get it running till i ran out of starting fluid. i have the newest software 1.33 and the newest cable took 7 months to get got it just before big one in japan. ihave tried the set up on 3 200 hpdi motors and it will not link up with engines, i tried 2 different laptops 1 with win 7 and one with xp, im out of ideas any direction would help, the guy need his boat for charters, anain any help out there i would be thankfull. i have wealth of info on merc, mariner, johnson/ evinrude, yamaha, m/c, volve about 40 years worth so if i can help some one on something else i would be gald to. thanks

[rodbolt17]

what error code is displayed?
you can check the high pressure rail with a multimeter.
if you suspect over pressure then try running it with the HP pump belt off.
it will run,just not at high speed.

[wildcater]

update on fouling hpdi

i did disconnect belt it has no effect on getting it run. cant get codes, thats one of my problems i cant get com with the ecu, my software is not working the boat has standard gagues, no working warning buzzer system and i have said except for the long block and new enjectors the rest of the engine has over 5000 hr on it only way i have been able to keep it running is disconnect the injectors and run it on starting fluid. im grabing at staws here 2 things are bothering me could i be getting to much oil or not enough air there seems to be very little suction pressure on intake and the mist coming out of the sparkplug holes oily, could the electric oil pump that feeds the vst tank be pushing to much oil into fuelalong with the mech oil pump thru the oil lines, do the 2 check valves in the electric oil pump to vst. are they used as restrictors or for keeping fuel from pushing back to oil tank. the manuel i have is very vauge when it comes to the electric oil pump. like i said im ckecking everything here. to day im going try to get one of local frind to bring his lap top and software over see if his will work, also calling yamaha tec support and see if they can help.