2000 HPDI Z200TLRY RPM Issues?????

[bjsetera]

Was wondering if anyone can help shed some light on a subject I am having problems with. I recently rebuilt my 2000 200HP HPDI due to a hole in the #1 head. It required a new crank, pistons, etc. During the rebuild, I took my injectors to Chris at Injector RX and had them checked. He brought me to the room that he tests the injectors and we discovered that 3 of the 6 were not working as they should be. He was not able to get them working, so I replaced them with new. He mentioned to me that I may also want to change the filters in the fuel pump and clean up the high pressure pump. I didn't do that as money was running out and now am wondering if that could be what is causing some of my issues.

I have about 15 hours on the engine since then which include the 10 hours needed for break-in. I am only able to get in the 4400 RPM range at WOT. I took the prop in to have it checked out and he said I would have to change it 4 degrees to get what I needed and that was not what the problem is. So I ruled that out, him knowing my boat brand, engine, etc. and comparing it to others.

During this past weekend, we had it out and were running and my RPM's started dropping from about 3900 which is where I typically run down to about 2500. I was able to trim my motor up and get about 3900 RPM, which would normally plane my boat out, and it seemed real sluggish. I then shut it off in the middle of the bay and started looking to see if I could see anything that may have come loose, holes, etc. When I checked the plugs, the bottom 2 plugs on the starboard side of the motor were fouled. I changed them out with 2 new ones that I had on the boat and it started and ran back at the 4400 RPM's that it was before and had plenty of power. We finished the day out fishing and on the way back in, it started the lower power thing again. Checked the plugs again, same 2 were fouled.

My question is, I am reading the repair manuals and am getting a little confused as to what the next item would be to check. Does anyone have an idea that you could throw my way as to what may be causing this. I plan on taking the fuel pump assembly in (vapor seperator and high pressure pump) and having Chris at Injector RX clean it as well as check the injectors again. I just thought while I had everything torn down, now would be a good time to check anything else that may be causing this issue.

As you can tell, I am more of a wrench turner than a mechanic. That is why I like this site so much and appreciate all you guy's help with this project. Anything anyone would suggest sure would be appreciated.

Thanks again,
Brad

[rumlefish]

Your vst filter screen is plugged,remove it and clean it or replace.Iam at the point now that i drain my tank and fill it with cleens and let it soak over night.Saves me from taking it off

[bjsetera]

Cleens???

If you don't mind explaining, what is the cleens product you are talking about. Is that something you do after each use or just sporadicly? I am guessing that you put it in the Vapor Seperator Tank and let it sit overnight and drain. I do appreciate the help.

Brad

[rumlefish]

Cleens is a GM product,i use it cause it works for me and is safe for the combustion chamber but there is other types of cleaners out there. I drain the vst tank and then spray a few onces in the vst tank by removing the small hose from the tank and use a plastic nozzle extension with the can to inject it.After it soaks i drain it and fill it again with cleens and run it.I only do it when i start to get a power problem. After that your hpdi should set you back in seat when you throttle up like they should do when working properly Hope this helps

[bjsetera]

Thanks...

Rumlefish,
Thanks for the information. I will work on that sometime this week when it slows down at work. I was also told that I needed to clean the high pressure pump (what ever that means). I thought I would go ahead and have my injectors cleaned again to make sure nothing is blocking them if the system is dirty. It makes sense that I should clean the fuel system as a whole, just not sure how to go about doing that.

Has anyone ever had to clean the whole system out that could give me a few pointers, I would appreciate it. I am hoping that this will be the fix.

Thanks again,
Brad

[bjsetera]

Filter looks good???? Now what????

Finally got around to pulling the fuel system off of the engine this weekend. I opened up the vapor seperator to look at the filter at the bottom of the medium pressure fuel pump and it looks clean to me. Kind of bummed as I was hoping it would be fouled up and that would be my problem. Overall, the inside of the vapor seperator looked really clean inside and while in there, I checked the needle valve as well as the float and all looked like new.

Can anyone else give me some direction as I have the fuel pump and vapor seperator on the workbench and would like to check anything else out while it's off.

I can't figure out how to attach pictures of the filter, so I'll try to figure that out later.

Thanks for any help anyone can send my direction.

Brad

[rumlefish]

Brad i know with my hpdi when the filter plugs you cant tell by looking at it you have to remove and try blowing through it.Thats the only way you will know for sure if its restricted

[Finisher]

vst filter will limit you to the 4400 range you can take it off and as long as it is not distorted clean it with soap and water, dry and reinstall. the other filter is a canister filter right above your vst that filters fuel before your high pressure pump. that should be changed. you can try blowing thru it, if you can't or its difficult then it is blocked. when that clogs it has the same signs your having. as for the high pressure pump it can be sent out and rebuilt/ cleaned it has filters but if it isn't broken don't mess with it. the only maintenance for the high pressure pump is a gear lube change that your dealer should do. if your high pressure pump was clogged you would have trouble starting idling.

p.s you will need a flat head screwdriver and a small hose clamp to change the canister filter. the connector on the filter is tricky but not hard. push the hose into the canister coming from spark plug side (stainless steel elongated cone shape) then push the black insert toward the spark plugs then remove the hose. the vst side you will have to remove the crimp on connector and replace with a hose clamp.

[bjsetera]

Will do...

Rumlefish,
Thanks for the reply. I took off the filter and was able to look thru as well as blow thru. It looks clean as can be.

Finisher,
I have the seperator on order now and plan on replacing it when I get it.

Thanks for the replies guys. One thing about all this work, I don't think there will be anything on the engine that has not been rebuild, bought new or cleaned and checked at this point. I guess all that will be left is the sync and link check and hopefully all will be good.

I did try and check the o2 sensor since I had it at the house, but I do not understand how to check it with a multimeter. I tried what the link for "Servicing Yamaha's Super Sniffer" said to do and could not get a reading, but I think that may be because of my stupidity. If anyone has a good "step by step" for multimeter dummies, that would be a great help.

I love this site...

Thanks all,
Brad

[Tucker]

I hate to be the old woman here. Is your tank clean? I boggles my mind that guys with these HPDI's do all this engine work and then pump sh!t gas right back into the motors. Guys on THT with the HPDI's all seem to be going for the 2-micron fuel filters. Can't remember reading any thread about HPDI problems that wasn't related to a fuel issue. Seem to be bitchin' motors when they're running right. Wish I had a pair...

[bjsetera]

Thanks Tucker...

Tucker,
I will look at the tank and see if it has any crud in it. When I rebuilt the powerhead, I drained the tank but never looked in it. The gas that came out of it was clean from what I could tell as we were adding it to containers.

The tank is one of the "supposed to be translucent" tanks that sits under the console. What am I looking for in the tank, just particales floating in the remaining gas in the bottom of the tank? Like I said, trying to chase down a gremlin and wanting to know what to check for.

By the way, your don't sound like a woman. But you do sound like a grumpy old man

Brad

[Tucker]

Good grief Brad, you pegged it, grumpy old man is what my children call me. Cheez it's that obvious in my print word!

If you drained the tank that should be good. It's not fiberglass is it??

Running out of ideas. Quite frankly, since you split the case and rebuild an HPDI from scratch you have a lot more skills than most people on this forum including me. Is the ignition advancing? I believe the shop manual gives a pretty good procedure and values for testing the O2 sensor. There are several test harness' availbe for testing; some guys have luck using a paperclip. Not buying anything about the prop being bad. It ran fine before it blew up right? And, how did it blow up? Bad injectors would create a lean condition and I always thought that blew holes in pistons.

[bjsetera]

Thanks Tucker...

Tucker,
The tank is a white / translucent poly tank. It has gotten less translucent over the years, but still holds gas and you only have to squint and look at the tank in the right direction when filling to make sure you don't over flow it... When funds become more available, I may have to splurge on the fuel / speed gauge.

I do have the manual that speaks about how to test the o2 sensor, but it's the multi-meter part I am having problems with. I did fashion my own test harness that shows continuity through the wires, I just don't know how to figure the resistor part out on the multi-meter. I am not afraid to admit that I am electrically challanged...

I think the prop is ok for now, I'll deal with that later as I just thought the issue was related to the RPM's. That's why I took it in originally to the prop shop hoping they could shed some light. That's when he mentioned the problems with the HPDI's and the gas.

I had to rebuild the powerhead due to a pin hole in the #1 head that allowed water to drain into the piston bore. I didn't figure that out until I pulled the head and realized the problem and by that time it was too late. I went ahead and did a complete rebuild as I had to replace the crankshaft anyway due to the pitting problem the water caused. Luckily I didn't have any block damage that couldn't be repaired with a honing. While all was apart, I took the injectors to a local guy to me. His name is Chris and he owns Injector RX. I found him on the internet by chance and he happened to be local, so I went in to see him. He has been a huge help with the injectors and gas problems. We were able to get 3 injectors working, but the other 3 were toast. Replaced those 3 and now we're where we are today. I went ahead and had him clean the pump and flow the injectors. All are flowing decently, the new injectors are not flowing quite as much as the old, but they are close enough that we don't think anything will suffer. I should pick all up later today or in the morning. If you can't tell, this guy has really been great to deal with and communicated with me constantly. I highly reccommend that anyone needing injectors cleaned, contact him. I hope that the mod's don't mind me praising him as I don't see any sponsors that do injector cleaning, just supplying on the site.

I should have it started up this weekend after I get my parts from Boats.net and we'll see where I'm at with this gremlin.

Have a great day and thanks for the help guys,
Brad

[Tucker]

Keep us current with develpments BJ. Hopefully the Rodbolt will be back from vacation soon and chim in.

[bjsetera]

Update on progress....

Well, the grimlin is still at it. Up to this point, I have changed all the fuel filters, taken the high pressure pump to be cleaned, cleaned all the fuel hoses, ran gas through the hoses to check for trash (all clean), recleaned the fuel injectors, changed the plugs. I am at a loss right now and need to take a break before I start cussing and acting like a 2 year old that doesn't get their way. When running on the hose, it sounds "boggy" is the only way I can describe it. You can definitely tell it isn't right. It does sound good idling though.

I think I need to take it somewhere and have the fuel pressure checked. Does anyone know how much that typically costs or know of a cheap fuel pressure gauge?

I also need to get the o2 sensor checked. I still haven't been able to get that figured out...

Does anyone else have an idea of what to check. I guess I can just go down the manual and check all the sensors, but with my multimeter abilities, that is going to take forever...

Thanks for listening to the rant, needed to vent a little.

Brad