Yamaha 150 hpdi

[Jonny2490]

Hi is my first time here. I just bought a 2001 yamaha hpdi to put on my wellcraft 20ft. Am having some
Issues when accelerating. The engines idles pretty but when i accelerate it it doesnt go pass 3400 rpm the engine sounds like is lacking fuel. As soon as i stop it for a while and i turn back on it rare occasions it runs at 4500 rpm which gives me a top speed of 42mph but rpm
Diminish after a minute if running. So far i have change all pumps including VST, the mystery filters on the main fuel pump and the other smaller pumps. All engine filters are brand new , new water seperator. I had a mechanic do a diagnostic and is giving that the engine has 6653 hours and it really only has 500hrs. Pls am going crazy i dont know what else i can do to enjoy my
Boat i would really appreciate any help thanks Jonny.

 

[Capt Ken]

Re: Yamaha 150 hpdi

If the diagnostic computer says its 6653, then I would believe it unless someone has changed out the ECM. I didn't see where you changed the filters on the injectors.

 

[Capt Ken]

Re: Yamaha 150 hpdi

You also need to have the diagnostics running when this happens to see if you are losing high pressure. The regulator in the HP pump might not be holding.

 

[Jonny2490]

Re: Yamaha 150 hpdi

I did have the engine
Running when i tested the hp pump and the pressure was good besides that i have not
Done anything with the injectors since they seem to be fine. The mechanic that diagnosed my engine said the computer was bad. What i dont understand if the computer is bad wont the engine not even turn on ???

 

[99yam40]

Re: Yamaha 150 hpdi

need to monitor the HP fuel and low pressure fuel while problem shows up to see what is happening at the problem RPM.
Computer controls timing and how long the injectors fire to control fuel mix while looking at some sensors of the motor.

If injector screens are plugging and you have in spec fuel pressures it still will not flow the amount of fuel it needs

Make sure you have a Yamaha Trained tech looking at this motor

 

[Capt Ken]

Re: Yamaha 150 hpdi

I that mechanic is telling you the ECM is bad, you need to run far and fast and find someone experienced in the HPDI engines

 

[Jonny2490]

Re: Yamaha 150 hpdi

Ok i will try that thank you for your help

 

[Jonny2490]

Re: Yamaha 150 hpdi

Sorry one more thing when the mechanic when to do the diagnostic he wasnt able to turn on the engine from the computr and also it telling him that there was something wrong with the shift sensor switch. Which we checked after and was ok. And also last time i took out the boat the oil gauge started beeping that it was low and as soon as i would turn of the engine and wait a while and turn back on it would work fine until it started beeping again for oil then the engine would reduced rpm as soon as the oil gauge came on. I put refilled the oil tank and it still shows the oil is low. What i dont understand why
The engine slows down when the low oil gauge turns on.

 

[Capt Ken]

Re: Yamaha 150 hpdi

You just told me all I needed to know. The technician has no idea what he is doing with the diagnostic system. Find someone with experience. Every engine will show a shift fault. It due to someone trying to start the engine while not in neutral. So that tells me he is inexperienced.
Only the main tank being low will trigger the reduction in rpms, not the tank in the boat. When you cycle the key, you are just resetting the system.

 

[Jonny2490]

Re: Yamaha 150 hpdi

Ok thank very much am having the engine
Checked out by another mechanic tomorrow and i will know now if his trying to ripped me off thanks guys for the help i will keep you posted to se if i solved the issue.

 

[Charlie in TX]

Re: Yamaha 150 hpdi

I recall one of the hpdi experts posting about the early units (pre 'o2 iir) not reporting the proper hours. Not a big deal. Glad you are taking it to a new mechanic.

 

[Bigrbass2]

Re: Yamaha 150 hpdi

Sometimes the sensor in the main oil tank will break a wire and cause the low oil horn which will put the motor in limp mode less than 1800 rpm and missing when you try to accelerate

 

[Jonny2490]

Re: Yamaha 150 hpdi

Ok so i finally finished the boat i took it to a mechanic and the issue was the sensor that goes next to the shift switch. This sensor lets the engine know that its no longer in neutral which takes the engine from working on 4cylinders to 6cylinders, this is why i would not go over 3200 rpms and had no power the sensor was bad and i was running in 4 cylinders all the time. In case anyone is gonna buy amd hpdi the engine runs great i have a 20ft wellcraft and is running at 5500 and getting 45mph. Just remember to check sensor, fueline and specially the mystery filters in the top fuel pump. Thank you all for your great help.

 

[echapa13]

Re: Yamaha 150 hpdi

Ok so i finally finished the boat i took it to a mechanic and the issue was the sensor that goes next to the shift switch. This sensor lets the engine know that its no longer in neutral which takes the engine from working on 4cylinders to 6cylinders, this is why i would not go over 3200 rpms and had no power the sensor was bad and i was running in 4 cylinders all the time. In case anyone is gonna buy amd hpdi the engine runs great i have a 20ft wellcraft and is running at 5500 and getting 45mph. Just remember to check sensor, fueline and specially the mystery filters in the top fuel pump. Thank you all for your great help.

Hi I think I'm having the same problem that you use ti have can you take a picture of the sensor, to look mine and to see if these is my problem?

I will really appreciate!!!!

 

[Jonny2490]

Re: Yamaha 150 hpdi

Please write me an email i will send you all the pics .jonnysotolongo@yahho.com