YDS AND TPS VOLTAGE

[SKfishing]

Do you know if all the fuel goes thru the vst pump before getting to the hi pressure pump I ask because I changed all the filters on the boat and the ones in the injectors and every filter was spotless not a speck of trash but I didn't know about the four in the hp pump so wouldn't there have to be trash in the vst screen to be in the four mystery filters

Yes it does but there is a reason they have filtration at each stage. It is possible for part of a fuel line, or the canister filter, or possibly part of the pump to get caught in the mystery filters. I really don't think this is your problem, but it is worth looking. The mystery filters restrict fuel flow to all cylinders equally, so it will idle ok, but it won't reach normal WOT. When they are severely restricted, the engine will almost completely shut down when you punch the throttle. When slightly restricted, coupled with a slight restriction at the injectors, you can have individual cylinders drop out causing all kinds of stumbling issues.

[skeeter21i]

I agree with you being my wot is fine

[SKfishing]

Strange thing is after you get past 800 rpm it runs great will turn 5700 rpm at 75 mph like it always has just won't idle

I have followed the HPDI threads for years and don't recall seeing this situation. First thought is timing advanced too much. It doesn't sound like typical fuel restriction/injector issues.

[skeeter21i]

here is two scans one at 500 rpm one at 1000 rpm not sure if that will help

4.Engine Monitor
Monitor Item (DATA)		Result	Unit	Monitor Item ON/OFF			Result
Engine speed		500	r/min	Firing of cylinder #1			Yes
Fuel pressure (7.0±1.5)		6.66	MPa	Firing of cylinder #2			Yes
Fuel pressure (1015±217)		965.72	psi	Firing of cylinder #3			Yes
Atmospheric pressure		1001.9	HPa	Firing of cylinder #4			Yes
Atmospheric pressure		29.7	inHg	Firing of cylinder #5			Yes
Ignition timing		ATDC 3	deg	Firing of cylinder #6			Yes
Battery voltage (12-16)		13.55	V	Starter switch			OFF
TPS voltage (0.5-4.5)		0.63	V	Engine stop lanyard switch			OFF
Throttle valve opening (0-90)		2.8	deg	Main switch			ON
Fuel injection duration		1.3	ms	Shift position switch			OFF
Water temperature (below 90)		47.5	°C	Water detection switch			OFF
Water temperature (below 194)		117.5	°F	Oil level switch (remote tank)			ON
Intake temperature (below 70)		15	°C	Oil level switch1(engine tank)			OFF
Intake temperature (below 158)		59	°F	Oil level switch2(engine tank)			OFF
Electric oil pump		Low		Oil level switch3(engine tank)			OFF
				Water temp switch (overheat)			OFF
				Dual engine system switch			OFF
				Shift cut-off switch			OFF
4.Engine Monitor Monitor Item (DATA) Result Unit Monitor Item ON/OFF Result Engine speed 1000 r/min Firing of cylinder #1 Yes Fuel pressure (7.0±1.5) 6.71 MPa Firing of cylinder #2 Yes Fuel pressure (1015±217) 965.72 psi Firing of cylinder #3 Yes Atmospheric pressure 1001.9 HPa Firing of cylinder #4 Yes Atmospheric pressure 29.7 inHg Firing of cylinder #5 Yes Ignition timing BTDC 3 deg Firing of cylinder #6 Yes Battery voltage (12-16) 14.36 V Starter switch OFF TPS voltage (0.5-4.5) 0.64 V Engine stop lanyard switch OFF Throttle valve opening (0-90) 2.9 deg Main switch ON Fuel injection duration 1.09 ms Shift position switch OFF Water temperature (below 90) 36.5 °C Water detection switch OFF Water temperature (below 194) 97.7 °F Oil level switch (remote tank) ON Intake temperature (below 70) 19.7 °C Oil level switch1(engine tank) OFF Intake temperature (below 158) 67.4 °F Oil level switch2(engine tank) OFF Electric oil pump Low Oil level switch3(engine tank) OFF Water temp switch (overheat) OFF Dual engine system switch OFF Shift cut-off switch OFF

[SKfishing]

https://www.injectorrx.com/fuel-inje...uel-injectors/

I still feel like you need to eliminate a leaking fuel injector(s). You can hook a fuel pressure gage up to the schrader valve at the VST. It should go to 50.8 psi at key on for 5 secs and then fall back to 43.5 psi and hold.

[skeeter21i]

Ok will check it out

[skeeter21i]

If I have leaking injectors would I be able to tell on the vst test would it keep falling below the 43.5 psi

[skeeter21i]

https://www.injectorrx.com/fuel-inje...uel-injectors/

I still feel like you need to eliminate a leaking fuel injector(s). You can hook a fuel pressure gage up to the schrader valve at the VST. It should go to 50.8 psi at key on for 5 secs and then fall back to 43.5 psi and hold.

I think you are right on the leaking injector when I trim the motor up at idle the rpms go up and when I trim down the rpms go down I'm thinking when it's up the extra gas is going to the piston and when it's down the gas is covering the plug and fouling it so who do you use to clean yours I'm going to send them off after Christmas here is the video

[skeeter21i]

And at high rpms the motor can handle all the fuel so the leaking injector doesn't effect it like at a idle

[SKfishing]

Fuel injector man, injector rx, Brucato all come to mind. Fuel injector man is probably the cheapest at $20 each. You may want to visually inspect the butterfly and reed valves. I would also suggest getting a service manual. There is a lot of good info and troubleshooting guides in it.

[skeeter21i]

Ok thanks

[Ranger519VS]

I think you are right on the leaking injector when I trim the motor up at idle the rpms go up and when I trim down the rpms go down I'm thinking when it's up the extra gas is going to the piston and when it's down the gas is covering the plug and fouling it so who do you use to clean yours I'm going to send them off after Christmas here is the video

the rpm varies when running the tilt because of the reduced back pressure when tilting up

[skeeter21i]

Got the injectors back ran great for about three minutes then lost power blown number 4 ☹