See full version: Service functioning HPDI high-pressure fuel pumps
I typically run the engines at wide open throttle for a couple of minutes headed back into the ramp to check to make sure that they are turning the usual number of RPMs. The engines have been very consistent and both of them have been turning 5300 – 5400 rpms in smooth water, with the tabs up and the motors trimmed out. The last trip, the starboard engine was only turning 5200 RPMs, but that's only about a 2% decrease. [links]
I have a pair of 2005 200 HPDIs with about 700 hours on each engine. I am the original owner. I have been diligent about scheduled maintenance and replacing the fuel filters in the bilge. I have had very few mechanical problems with these engines – the voltage regulator on the starboard engine had to be replaced a couple of years ago and the medium pressure pump on my port engine failed last year. I am way overdue for service on the high-pressure fuel pump and associated filters. The fuel injectors have never been serviced. I have the software program to analyze engine function. I've only tested the engines at idle in neutral and in gear up to about 800 RPMs. The normal fuel high pressure range provided by the software is 725+/-116. Over three scans done in the last nine months, my starboard motor has been running 696± 2 and the port pressure has been 712±3.
My question is, since I am overdue on a time basis for the high-pressure pumps to be serviced, should I go ahead and have them serviced even though they do not seem to be malfunctioning? Do the high-pressure pump usually fail suddenly or do they gradually lose the ability to generate that very high pressure? I am also inclined to have the fuel injectors serviced at the same time.
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The HPDI does not utilize a knock sensor. Could this be a reason (one of many) for detonation that is seen somewhat often in a big block HPDI? Throw in a partially clogged injector and it will only get worse. [links]
The nominal pressure for the HPDI HP pump is 1015 psi. Plus or minus 217 psi. Yes friends and neighbors, 217 psi.
Detonate a block, install a new block with the old pump and kablowey. There goes the new block. [links]
If my math is correct 217 psi on the low side is over 20%. In theory that should also be 20% less fuel being delivered if and when the pump output is 798 psi. That would result is a much leaner air/fuel mixture.
A lean air/fuel mixture is more prone to detonation than is a normal or rich air/fuel mixture.
Just wondering why Yamaha does not call for a check of the HP pump when a big block HPDI shows signs of detonation? I stopped wondering years ago why there is no knock sensor. But there is a water is fuel warning.
Any questions, please do not hesitate to call 1.800.381.2065 for more information. We can help clean your Yamaha HPDI pump and injectors, and save you money too!
Contaminants and dirt settle on the sensitive reed valve like metal plates and check valves inside the fuel injection pump. Resulting in a pump that will not longer hold pressure. Dirt and contaminants also accumulate on other sensitive and precision internal components and eventually will cause premature failure. The smallest amount of debris can cause the piston to become stuck.
By disassembling the entire HPDI fuel injection pump, we have the opportunity to inspect and service all components. more
We recommend this inexpensive service on a regular basis, especially when the GDI injectors that are supplied with fuel from these Yamaha HPDI fuel injection pumps, become clogged and require cleaning or replacement. For dirt to get into the GDI injectors it had to travel through the HPDI pump. here
We might be able to help with other make and models of high pressure direct fuel injection pumps.
Water accumulation due to its presence in the atmosphere and ethanol in the fuel causes the Yamaha HPDI pump’s internals to become rusted. Internal valves now no longer seal properly and the HPDI pump loose pressure.
I have twin 200hp HPDI motors and the port motor will not rev beyond about 2400 rpm and is rough running. Replaced all filters including the small basket filters in the injectors and pump. Mechanic with YDS checked out and first replaced the TPI which made no difference then says the high pressure pump is not putting out correct pressure at higher rpms. This is an expensive part new so I sourced a used one claimed to be taken off a good running motor. Mechanic installs this pump and says that it is no good also. Losing confidence in this mechanic. What are the odds of two pumps being bad? Is it possible to rebuild these pumps like diesel injector pumps? I should mention that I'm in a small town in Baja and this mechanic is pretty much the only **** in town. Any help.
I suppose I should mention a few of the things I have done to try to diagnose. I think I have ruled out bad fuel as the tank has fresh fuel and the Stb motor runs perfectly. I also tired swapping the ECUs and Injector Drivers from the good engine to the bad and made no difference. The plugs on the bad engine are very black and sooty looking, not wet at all.