Any Yamaha HPDI experts out there? still bogging down

[flounderpounder225]

Have the basket filters in the hp pump been changed, something else I noted, you mentioned o2 sensors, hpdi's don't have 02 sensors?  The OX66 motors do, like JD's motor.  I think this is still a fuel issue just my opinion, check this long thread out on THT, it is what prompted me to learn and dive into replacing my basket filters on my HP pump.. Just more knowledge for you on these DI motors
http://www.thehulltruth.com/boating-for ... rt-ii.html

[BTF112989]

I have replaced the basket filters in my engine.  Your post about them here made me look into them & with some more help from threads on THT, I got them changed out.

My engine does have an O2 sensor.  The earlier year hpdi's had O2 sensors, then they got rid of them in later models.  I don't think the 250 hpdi ever had one.  In the 2001 2.6L blocks they still had the O2 sensors, although they only take reading up to 1500 rpms.

Well, I've lost a lot of confidence in my dealer due to the tech saying that he couldn't do anything else.  After some advice on THT, I am going to bring out the voltmeter & take some readings to make sure I have enough spark under load.  I figure I can do that & save myself a few hundred dollars.  If that doesn't produce any results, then I will pull the injectors.

Thanks,
Ben

[flounderpounder225]

Thanks for the history on the HPDI and the 02 sensors, I didn't know some had and some didn't, I'm always learning a little more on these motors.  You will really have an education when you figure this one out, and you will.  All my hesitation and sputtering at higher rpm has consistently been fuel related, so that is where I think your issue is, the scan by the mechanic can tell a lot of things but can't determine what is happening at the fuel nozzle of the injector, they can measure voltage signals, and fuel pressures, butnifnyour spray pattern is jacked up, it won't run right.  Good luck, and I'm waiting to see the outcome of this, I know it's driving you nuts, but keep poking around, you'll find it.

[BTF112989]

Well everybody, its been awhile since I have updated/responded. I drove back to Nashville from knoxville during finals week to do a few last minute things to the hpdi as a last ditch effort. My spark plug boots were all ready between 5.66k & 5.82k for resistance values which falls in the 4k-6k range that they are supposed to be in. I also checked, cleaned, and tighten all grounds, as well as the battery. I found my tps sensor was a little bit out of tolerance, so I readjusted that. Since I made all of those adjustments, I ran the boat for 4 hours. It only did two small hesitations like you would run over a tiny stick in the water. It seems to do it less & less the more frequently I run the boat.

So the final decision was made to pull her down to Bonita Springs! We pulled out yesterday & drove through the storm from Hell all the way down. It was pouring the rain when we left Nashville & as we headed south on 75, the storm moved east slowly right over where we were on 75. We finally drove out of the storm in Sarasota. 15 hours later, we pulled into our drive way!

This morning I had to dry everything in the boat out & get ready to take it to the storage place.

I just wanted to let yall know that I pulled the trigger & made it down here!

Leaving Nashville:


Unhooked in Bonita Springs:


We'll see how she runs down here & maybe take her to a better mechanic that's more knowledgeable on these engines. Anyone have any suggestions for yamaha mechanics down here?

Fishing suggestions around Wiggins Pass, Estero Bay, Ft. Myers Beach, Sanibel area?


Thanks for the help everybody,
Ben

[BTF112989]

Hello friends!
I am about to go crazy right now, take a chainsaw to the transom, and wave goodbye to the HPDI as it falls to the bottom of the lake. I just had the engine sit at the dealer for 6 weeks during the middle of the summer because it became undrivable. I had the boat in Knoxville as I finished up my last few classes this summer. One day I took it out on the lake, but everytime I tried to get up on plane it would bog down & wouldn't get up on plane. It would run rough at 700rpms, but would not go above 700rpms without this awful gurgle sound. I could push the throttle to the floor, but it would only hit a very rough 1800rpms & it would sound like it was missing/gurgling. So after that episode, I pulled the boat back to Nashville to go to the mechanic. He is the 5 star certified or whatever mechanic that is the best in the state or whatever. Goes to Japan to learn more, blah, blah, blah. So I leave it there for 6 weeks. He calls me this past Monday & says that he gives up. The engine has messed up when he has lake tested it, but he cannot pin anything down. I have replaced the external racor fuel filter, the medium pressure fuel filter, the VST filter screen, the mystery fuel filters in the high pressure fuel pump, and gotten all of the fuel injectors cleaned as well. The fuel system is clean. The gas tank was new in 2008. The mechanic said the fuel pressure never dropped according to the yamaha diagnostic system(YDS) during its bogging spells. He also said that the engine would have blow during all of his testing if it was mechanical/fuel related. He firmly believes it is electrical. He thinks either the ECU or the wiring harness. The coils have been tested & they are okay.

So anyway, we get it back from him & we put the engine in. I run it around for an hour & it runs greats! I am leaving a cove on the lake, the engine goes from 3800rpms to 1800rpm in a quick but steady fashion. If I push the throttle forward more the engine seems to "gurgle" more, but won't go any faster. It keeps doing this & will only max out at 2100rpms at WOT. So I back off the throttle & drive at 800rpms. However, the engine should be at 2000rs at the throttle position I am at. I cruise for 15 minutes, then all of a sudden the engine jumps to 1900rpms. I push the throttle further & it planes off perfectly. Like nothing happened! It's running great! I run for about 7 or 8 minutes at 4200rpms, then the engine suddenly slows down 200rpms at a time until we hit 2100rpms. I back off the throttle & it keeps gurgling/ running rough. It will run at 700rpms, but anything over that will cause it to gurgle & bog. If I press in the button on the side of the throttle to rev it in neutral, it runs very rough & will sometimes die. If I throw the throttle all the way forward, it struggles to hit 3000rpms. But after a few minutes, something suddenly kicks off & it runs great for a few minutes before it will bring me back down off plane again, it's a repetitive cycle.

Apparently the dealer has been unable to experience this because he hasn't run it for the hour or 1.5 hours it takes to cause this. Either way, he has given up on it. He ran many tests, called yamaha, tried to get a tester ECU for this engine but was unable to, etc. he believes its electrical, which I believe too.

The mechanic just keeps telling me to run it until a catastrophic failure of the ECU or something, but I refuse to accept that as an answer. An engine that can't make it across the lake to a beach that is 10 minutes away is useless to me. I can't be handicapped or afraid of an engine. I want to know I can make it to my destination. I have lost my confidence in this engine.

I took many videos of this engine to show people, because a video can show the problem much better than I can explain it. I'm not exactly sure if I can post a video, but my phone number is (615)804-6952 if anyone wants to see a video.

I just graduated from the University of Tennessee with a mechanical engineering degree, but I am still interviewing/applying for jobs currently, so my income isn't ideal for a new engine. However, throwing $2500 into an engine that's only worth $4000-4500 isn't smart either.

I saved up $5000 & bought this engine as a scratch & dent deal back in 2005 brand new, so I did get an engine for half price back then.

I could dive into my savings account, buy a new engine, then use my first year of savings from my future job to replenish the savings account. However I hate to touch savings for something like that. I do have the discipline to replenish it though.

I guess I'm asking if anyone has any last minute ideas?

I'm just to the point where I've lost confidence in the engine. I wish outboards had never left the days of coils, points, condensers, carburetors, etc.

My 1956 35hp Johnson & 1957 10hp Johnson will run forever on my Jon boat!

HELP ME PLEASE!!!!!

-Ben

[fitz73222]

My gut tells me this a basic sensor issue and the ECU is getting a bad signal from one of the sensors. You're getting such a huge variation in running quality at various RPMS I would be looking at a throttle position sensor or whatever variant of mass air flow sensor(s) this engine uses. I would also 100% eliminate a high temp issue by measuring the cylinder heads and exhaust temperature by using a laser temperature probe out on the water, under a load and measure the temperature at the thermostat housings, then the entire cylinder head (s) followed by the exhaust plate temperature and see if one cylinder bank is running hotter than the other or the exhaust temp is high because the ECU is also getting a signal from engine temp. Typically there is going to be some sort of module that's going convert a heat signature into a voltage signal for the ECU to read unless the sensor itself does it. The best of all worlds is to find a dealer or engine builder that has a test tank with a suitable test wheel or propshaft mounted dyno that can run this engine throughout the throttle range at the shop to best replicate the situation you are experiencing out on the water. I have seen enough times where engines pass numerous tests at the shop only to start running bad an hour into a trip on the water.

[Blue Agave]

Ben, if you do decide to throw in the towel I would recommend you go American.

http://www.boattest.com/engine-review/M ... FourStroke

[gran398]

Ben, you've requested advice, here's mine:

Don't marry for money.

But don't let it stop you.

[seabob4]

I am totally with Farley on this one. You have most likely one sensor that is malfunctioning, sending either an erroneous voltage or resistence output to the ECU, which is reading that as a fault and causing the engine to go into limp mode.

I would think your 5-star mechanic can put his computer on the motor using YDS and read the fault codes that SHOULD be stored in the ECU.  There is no reason to have to run the motor for an extended period of time with the diagnostics running, wait for a failure mode, then see what's up...all your issues you've had should be stored and readable...

[BTF112989]

Thanks for the replies guys! Both serious & funny. I am with you guys on the sensor issue telling the engine or ECU what to do. I tried the boat out again yesterday. Ran great for the 20 minutes it took to make it from the house to an island on the lake. I hung out there for 3 hours or so, and it ram great again when I drove back to the house at the end of the day. I set the boat back down to idle speed put it in neutral for a second, then decided to take it for another quick spin. As I tried to accelerate the engine began to stumble again & seemed to only top out at 2500rpms. I eventually got it to plane off & run at 3000rpms although it seemed a little rough & the throttle was pushed all the way forward for me to hit 3000. At that throttle position I should have been at 5500.

Anyway, on the lake I was thinking it was either a throttle position sensor or a problem with the actual throttle. Right in line with what you guys said. After researching a little bit, I found some similar stories to mine when I searched "hpdi shift selection switch". Right behind the slide mechanism that the throttle & shift cables sit in, there is a neutral safety switch/shift selection switch/shift position indicator. It is one switch that people call a lot of different names. This engine has the 2 cylinder cutout at idle speed & in neutral. This switch is what tells the ECU that the motor is in neutral & only let's it run on 4 cylinders. When it goes bad, the engine will only run on 4 cylinders even in gear & will top out between 2500-3000rpms. The whole time the ECU is thinking you are just revving the engine up in neutral instead of being in gear. Sometimes the plastic tips that can be adjusted on the end of the throttle & shift cables aren't adjusted exactly right & cause it act weird. I may try & adjust the tips to see if that does anything. But I will probably just order the $40 sensor so I will have it on hand & I will be able to salvage some of my summer.

Here was one guy's account of his shift selection switch going bad:
"Check the little mocro switch for the shift position. They will drop two cylinder (spark) while in neutral and then fire them back up in gear, and the motor is strong and can run even when the switch is bad and you will again notice it when passing 3000-3500 because if it still isnt switched to the "gear" position, the ECU will drop another two cylinders and then you will feel and see the engine shaking. Been there done that. Its tricky because for the longest I could swear it was happening to me, but never completly failed, then one day it was all the time. Pulled the switch and it had finally broken off the last remaining piece under the metal strip."

Seems similar to my issue. What do y'all think about that?

I'm not sure it will fix my little 200-300rpm drop problems I have mentioned in the past, but I think it should fix this big problem I have had recently. And maybe the two problems are all related to this switch!

Thanks for all of the advice guys!

The link to that mercury four stroke makes me want to go out & buy one right now, but I would need to win the lottery first.

-Ben

[gran398]

Good sleuthing, sounds like you're onto something there Ben.

[BTF112989]

Hello everyone!
I put in a new neutral safety switch/shift position switch/shift position sensor in the hpdi & it ran great for about an hour like it always does. Then it brought me down off plane & down to 2800rpms. So that idea didn't work. I'm now thinking its the ECU. It just flips on & off like you are flipping a switch. It's happening more & more often now as I drive it.

Anymore ideas?

I'm about to put the hpdi back on my old 1992 sailfish 190 sport dual console with a questionable transom then sell the whole pile. Maybe my savings & the funds from that will be able to get a new mercury 150 four stroke!

[Capt Matt]

5yrs of warranty and hassle free boating sounds like a plan if you can swing it. You will love that merc 150 motor. I'm the test subject on the motor for my local marina as its the first one they sold I have 200hrs already and no regrets switching to a 4 stroke. Each time I take it in for a oil change the mechanics are more and more impressed with the simplicity of the design, and how few moving parts it has compared to other fourstrokes
Think of  stress free boating again, I,m sure you can eventually solve the hpdi problem but how much more money do you want to put in a motor that you will have no confidence in?
Good luck
Capt Matt

[BTF112989]

Hey guys!  Sorry about the lack of response.  I kind of fell off the grid for about a month between job searching, interviewing, and getting my first real job after college.

I actually ended up pulling it in to the dealer again a little over a month ago.  I finally used the boat enough to the point where the engine would run great for 25 minutes and screw up continuously for the rest of the day.  So I pull it in there and asked if the Yamaha Tech could ride around with me until it messed up because he had still never experienced the real bad rpm drop.  He couldn't because he was lake testing another boat at the time, so I just pulled the boat down to the ramp he was testing the other boat at.  I asked him if I could run it on my own until it messed up, pull the boat out and back to the dealer, then plug in the computer as soon as I got back to see what the deal was.

I drove around for 30 minutes or so, the engine messed up, I pull it out & back to the dealer, we hook it up, and of course...IT RUNS GREAT out of the water.  Of course that would be my luck.  

So I leave the boat there for a month, call several times and they say "they're working on it", then I call and they tell me once again that there is nothing they can do to it and that I should pick the boat up & there will be no charge.  So I go to pick it up because its better off being in my driveway, covered up, dry and clean while broken then sitting uncovered in their lot.  I get there & they want me to pay $78 for gas that they had put in it.  I brought it in with 15 gallons in my 28 gallon tank.  If the boat gets close to 3 mpg, I see no way that the Yamaha tech drove it 45 miles around on the lake and could not get it to screw up.  If you need more gas, why fill it all the way up to the tune of $78?

So I left the boat at the dealership with the promise that the owner of the dealership would call me and make everything right.  Well, he finally called me today and I went over everything that I have changed out and the entire course of events.  He finally said that he has a lot more experience than his technician, and he had some ideas to figure my problems out!!! He even said that he would acquire an ECU, wiring harness, and fuel injector driver (all of which the technician said he was unable to acquire) that fits my engine to narrow down and possibly solve my problem once and for all!

So things may take a turn for the better in the next couple of weeks!

I have been lusting over that new Mercury 150 4 stroke that Capt Matt has.  Right now I want to just be done with my current engine and get the new Mercury, but I don't think I can swing it financially.  Maybe one day in the future!


-Ben

[seabob4]

Wonder if that "technician" will have a job come next week?  If the owner was aware (or unaware) in regards to everything that has transpired over the past MANY months...well, I just have to wonder as to his "faith" in his staff...