2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

[Cow Addict]

Ok folks-

Looking for some good ideas to solve my powerloss issue.

TYPE- 2002 HPDI 150

SYMPTOM:
I have a brief powerloss at engine speed over 3500rpm. Just enough to lurch you forward. RPM drop for a split seccond then kick back up. I can make this happen if i aggressivly power-up or if i am running over 3500rpm and get into some wake or chop and the boat starts to bounce arround. Here is the tricky part... If i slowly power-up on flat water i get on plane and i can max throttle without a problem and run fine, but If I start to bounce it get the powerloss.

THINGS CHECKED:

fuel is clear

Water separator filter clear (replaced anyway)

Fule line checked for kink

Fuel pump is good

VST drained - (clear)

In-line fuel filter changed

VST filter changed

VST pump is good @ 50psi (tested while symptoms were happening)

Batt terms are clean and tight

Ignition seems tight (yanked on harness to see if anything loose not a problem)

Visual check for loose ground (looked good. verry little corrosion cleaned what was found).


I am fresh out of ideas with the exception of replacing the fuel pressure sensor on the VST.

I am open to suggestions....


Thanks in advance!

 

[rodbolt]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

do I have some ideas?
yes.
but first ya gotta explain this sensor on the VST.

 

[Cow Addict]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

Pressure sensor... Meant to say fuel pressure regulator.

 

[JUSTINTIME]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

im going fuel pump

 

[Cow Addict]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

I assume you mean the high pressure pump? Given what I have already done.

 

[JUSTINTIME]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

nope LP pumps

 

[Cow Addict]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

med pressure is fine 50 lbs constent. Main bladder pump is fine. besides, the vst tank holds enough fuel to run for several minutes. these were the first othings i checked.

thx

 

[JUSTINTIME]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

put a vacuum pressure gauge before fuel filter in plastic container, then after it, then after first pump,, then after second pump

 

[rodbolt]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

ok, if your medium pressure is holding at 50 PSI while its cutting out I dont suspect anything between the liquid level in the tank and the inlet side of the medium pressure filter.
use either the laptop or a DVM to monitor high pressure fuel.
on the High pressure pump there is a sensor, P-B you should see about 2.8-3.2V at all times especially above 1800 RPM.
if your holding 50 PSI that means most likly the pressure regulator is doing its job,holding pressure at 50 PSI.

 

[Cow Addict]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

That sounds like the right direction... Now i just need to get my hands on a three-pin harness tester. Or McGyver something from parts.

Anyone got a picture of a tester? I assume it's just a three pin Male & Fem with a couple of leads to attach a DVM?

 

[rodbolt]

Re: 2002 HPDI 150 - Powerloss at Higher RPM- Out of ideas!!!

for a one shot use I would use paper clips and black tape to back probe the connector.
striaghten a pair of small paper clips,insert the parralel with the wires you need to test from the back side of the connector,attach meter leads with alligator clips and use tape to insulate and hold them in place.
that engine also uses the single driver for the injectors, you can use a DVA adapter with your DVM and monitor injector driver voltage by back probing each injector.book says about 65V but I normally look for all are within 5 V of each other.
also monitor pulser coil output voltages, if it overvolts the ECU wont catch it but it can make an injector drop out.
you may also wish to monitor TPS output when it fails.
if you have the laptop on it when it fails it will highlight any monitored failure in red but once it goes away the laptop will go back to normal.
it will log the last 13 min or so of run time if you hit the save key when it hiccups.