Yamaha HPDI Question

[Flat_Out]

First off, I bleed black!! I am posting this for a friend. He has a 200 HPDI that is missing at acceleration and no top end. What happens is you can put the throttle to the dash from idle and it will just miss and will not plane off. If you accelerate slowly, it will plane off. Also, when running at 4400 RPM's, 3/4 throttle, if you go to WFO it will drop RPM's down to 4200 while the throttle is at WOT. As you back off on the throttle from WOT, the RPMS will go back to 4400 once the throttle is at 3/4.

The plugs have been changed along with all of the filters. Any suggestions where to look would be appreciated. He has a mechanic buddy that told him to take the VST tank off and apart and make sure that the filter in there is't clogged. Any thoughts on that??

Thanks

[mn808gade]

have had a couple of screens on bottom of vst pump covered w/one eighth inch of "stuff".(impurities in gas-plugged the screen). next problem spot is metal filter located above vst, in hp line. way to much money for yam to charge for this filter. motor has a lot of fuel thru it? then of these your problem. guys w/lots of hrs all have one or other. th
next metal filter i'm tryin a soak in seafoam and then a airhose backflush

[VectorPat]

Change ALL the filters and clean the VST and change its filter dont just clean it. Its also possible the belt driven HP pump can be plugged up as it has small filters in it 2 but its technically not serviceable. It can be cleaned but first you have to find the filters as Yamaha doesnt sell them and then the pump can be tricky to disassemble and reassemble.
I wouldnt try cleaning that metal filter, it is still a paper type filter and you may damage it trying to clean it then that material will get into your HP pump.

[CSD23]

My friend had the same problem. Change every filter and had the injectors serviced, to no avail. Found out that it was the HP pump, problem solved. I would start with changing every filter, somewhere around 11 total, and have the injectors serviced. If that doesn't solve it, look into finding a new HP pump.

[lance]

Yes, change all the filters before the HP pump, there are 3. One inside the VST, an obvious inline one, and one in the water separator filter. When changing the water separator filter, make sure the plastic screw on cover with the o-ring seals. I’ve had a lot of problems with that. If it doesn’t seal, you will lose the fuel supply to the VST. The HP pumps rarely go bad. As mentioned, there are 2 small basket filters in each pump. Check on BBC for detailed instructions on how to change all the filters including the HP pump basket filters. It is really pretty easy. All filters can be changed in about 2 hours. Standard automotive fuel injector filters fit the HP pump. I used NAPA #CRB 215001 which are about $1.50 each. I bet many HP pumps have been replaced due to these filters since Yamaha states the pump is not serviceable. Each pump retails for about $1300!

Suggest also checking the resistance of each sparkplug connector cap. The caps screw off the ignition wires. The spec is 4K-6K ohms. Sometime they go bad.
Good luck

[VectorPat]

About the only thing that can go bad in the HP pump other than the filters is the cam drive and the only time I have seen those go bad is when someone doesnt put enough oil back in it. There can be more than 2 basket filters in the HP pump depending on which motor you have, there is one that is not easy to find.
Thanks for the NAPA number, havnt seen that before. I have a private source I get them from but I have to buy 50 or 100 at a time.

[lance]

I haven't heard of a 3rd basket filter in the HP pumps. Can you provide a little more info on where it is located?
Thanks

[Superbender]

Lance great find on that part #,and yes sometimes there are 3 filters depending on which yr pump it is

[VectorPat]

I'll try to explain this but its hard, If you have a 2.6ltr motor, I dont remember if all of them were like this but if you look at the picture, the long square tube on the bottom, take it off and there is a passage with another filter in it. A 3.3 ltr has 2 pumps built into it.
http://www.dirtyinjectors.com/images/IMG_3895.JPG

[Flat_Out]

Guys,

Thanks for all the advise. We changed the VST filter and the filter on the external of the VST. Also changed the water sperator filter on the engine. Ran the boat and all power and RPM's have been restored. It runs like a champ. 5500 rpms and a clean acceleration out of the hole. The filter in the VST had a coating of crap on it, but the tank was spotless. Thanks.

[VectorPat]

That coating is from the ethanol, sometimes its from an aluminum gas tank being etched from the ethanol. It goes thru any water sep filter and accumulates in the VST. You may have also noticed the VST filter is deformed, ethanol also.

[Greg G]

I'm dragging this to the top as it has a lot of good info and I'm having a problem with my Yamaha. I have a 2007 Yamaha 250 VMAX 3.3L HPDI. Very good motor for me overall. I did a full filter service in June of 2012 and have used this particular motor very little since. This year, only 3 times so far this season. Last time out I am getting a very rough idle. The motor is spinning a 23" Rev 4 to 5800 rpm and 68mph on my deep V (ran that yesterday) with zero issues and has no problem getting up out of the hole and onto plane. Only issue is the low rpm idle, say below 2000 RPM. I run Yamalube, and the occasional ring free and sea foam through it.

Any feedback on what could be causing the idle problems would be great guys. Thanks in advance.

[Greg G]

Anyone? Please don't make me use the search function :nonod:

[ChrisCarsonMarine]

Call My shop ask for Chris Or Josh.

[lance]

Greg, check the low pressure (lift) pumps. The 3.3's have 2. The diaphrams seem to go bad quite often. They leak into the engine crankcase and can cause a rough idle and hard starting. Check this link:
http://www.bbcboards.net/yamaha-motors/239801-replaced-low-pressure-pumps-2004-225-hpdi.html

I got tired of my lift pumps failing so I removed mine and went with an electric pump in the bilge. At the same time, I removed the engine water separator filter since I always had problems with the top cap o-ring leaking and now rely on a canister water separator filter in the bilge area. This really simplified and cleaned up the under hood fuel system. I've had this setup for 2 years now. All my other factory filters are in place.

Check over on BBC. There are some great tips on keeping the HPDIs running great.