New Prolem A1 What do you think? Pls. Help - The Hull Truth

RocknReeln · 10-10-2008, 05:21 PM

A1 - again thanks for all your help and thanks for being on here. I have previously posted in this section that I have a pair of 2003 HPDI's Yam. I have changed the racors, the cannister filter, the filter above the VST and the filter in the VST. I have also changed the plugs. I cranked the engine and it is gasping and Konking out. I had the mechanic troubleshoot - we checked with the laptop - no codes that are relevant or serious. It did start to get hot and overheat and we replaced an impeller 9needlessly) that was in good shape. We did the followingtests - pressure at the VST (50), pressure at the plugs - all of them good - but only one was little bit damp and a little dirty for just being put in new. Then the mechanic disconnected the thermoswitch assembly Part # 688-82560-10-00 and it ran pretty much a little better.But he says he does not think it is the that sensor. He pulled the belt off the top and the engine ran remarkably better without konking out and steady. He says he thinks it could be the fuel injector pump (Big dollars)...and although Yamaha recommends replacement of the entire pump - he thinks he can pull it off and clean it, depending on what he sees. He's gonna check his manual and get back to me tomorrow about soing this....What are your thoughts?

Thanks.

A1 Outboard · 10-10-2008, 09:32 PM

Without a manual handy, 50 psi at the VST sounds too high, perhaps there is a restriction in the fuel regulator filter screen.

How did the motor run with the belt removed, that is what drives the high pressure gasoline into the fuel injectors?

If the mechanic is sure the high pressure pump is bad, he can contact Flagship Engines in Punta Gorda for servicing it and cleaning and flow testing the injectors also. That is a lot cheaper than replacement costs.

RocknReeln · 10-11-2008, 06:08 AM

It idled much, much better without the belt. The PSI at 50 is I think normal from what he said. Taking the pump off and sending it for cleaning sounds like a great 2nd option. I'm gonna call them.

A1 Outboard · 10-11-2008, 03:25 PM

Quote:

RocknReeln - 10/11/2008 8:08 AM It idled much, much better without the belt. The PSI at 50 is I think normal from what he said. Taking the pump off and sending it for cleaning sounds like a great 2nd option. I'm gonna call them.

Yep, 50 psi is OK for an HPDI motor. Send off all 6 injectors with the fuel pump to make sure everything is OK and flowing properly. Flagship Engine is an authorized Yamaha injector cleaning company.

RocknReeln · 10-25-2008, 02:21 PM

Well, I pulled the fuel pump and had my mechanic service it - it was clean. I think my problem was fouled plugs. I 'm gonna run some clean fresh gas , and some ringfree and see what happens out there. But it wasnt the filters (VST, etc) - wasn't the fuel pump or injectors -but the plugs were very fouled. We will see if the sputtering, stuttering, at idle stops after a clean run!