Yamaha 2001 HPDI

[Steven Algiers Pt]

To all of you boating finatics i am hoping that i can find the answer from one of you.<br /><br />I have this 01 150 HPDI, that is having to be started like a Merc, (cold start, throttle engaged). This obviously should not be the case as it is an HPDI, right? I have had the computer completely replaced by Yamaha, changed the filter that leads from the VST tank to the engine body. Still trying to find why this is still happening. If anyone has run into this problem please give a shout out.

 

[rodbolt]

Re: Yamaha 2001 HPDI

cause your dealers techs suck eggs.<br /> tell them to lay of the mudbugs and open the book.<br /> on the HPDI there are many reasons for this. do you have any other running symptoms? and why was the ECU replaced ?

 

[bigbrownbuku]

Re: Yamaha 2001 HPDI

the 01 was around the time of a coil/plug update for hard starting engines(v6). first thing to do would be to cross refernce the model/serial with ympe. a good place to start would be the tps especially if you use throttle to get it started. basically tell your dealer to read the book, if they can infact read it should be fixed fairly easily.

 

[Steven Algiers Pt]

Re: Yamaha 2001 HPDI

Originally posted by rodbolt:<br /> cause your dealers techs suck eggs.<br /> tell them to lay of the mudbugs and open the book.<br /> on the HPDI there are many reasons for this. do you have any other running symptoms? and why was the ECU replaced ?

Basically, i put the boat the in the water, starts immediately (no choke, no cold start) i run for 15-20 mins - fish for say the same amount of time, and that is when i have this problem of having to cold start, just a note, i am not losing pressure in the primer bulb, which i have replaced. The reason for the ECU replaced is my dealer(friend) said it was burnt up and they could not get a reading when they went to plug there laptop up. ??? Also, there are times after running and fishing that it does start with no choke and no cold start, however, it seems very sluggish and at a very low idle for 10-20 secs ...... pretty strange, i know. <br /><br />Again, thanks kindly for your reply and if by chance you have some further insight to my problem it would be greatly appreciated.

 

[rodbolt]

Re: Yamaha 2001 HPDI

to start with there is no Choke on that engine. if it was rigged with a push to choke key switch its cause they had one in stock and needed to get rid of it. the push to choke function does nothing on EFI and HPDI. if your moving the warm up lever at any start you need to reread the owners manual. moving the throttle can and will cause starting problems. the hpdi and efi and some carbed yams are designed to start with no throttle and no choke. its called prime start. if it needs throttle to start its broke and needs fixing before it dies. has the O2 sensor been tested in actual running conditions? the flame test in the book is worthless and it cannot be properly tested unless the gearcase is submerged in the water. and on the HPDI its been my observation that the low pressure pumps need replacing every 3 years or so, the O2 sensor must be cleaned/tested every 100 hours or so,regardless of the maint schedule. and the vapor seperator filter and the medium pressure filter needs replacements as well. when that motor starts in nuetral it runs on 4 cylinders. if you increase the throttle in nutral past about 15-1800 it runs on 2 cylinders. if a plug is fouled it will try to run on 3 cylinders or less in nutral. its a simple motor to test and trouble shoot. it will do it for you if you let it. my experience with the laptopis its a quickway to verify what is working and allow you to concentrate on what aint. if you suspect a bad or leaking injector watch the high pressure and medium pressure rails and see what they dowhile running and at shut down.<br /> its not voodoo nor black magic but it takes a thorough understanding of how and why it works. seems most the techs I run across are clueless or overwhelmed by the array of sensors and how it all interfaces. even though its high tech it still uses the basic suck,squeeze bang and blow methods.