Logo
FULL SITE MENU

200 HP HPDI Power Problems

S

sprokit

New member
"Hello Justin,
I looked throu

"Hello Justin,
I looked through the YDS manual, so I now know how to clear the codes...many thanks.
I was wrong about the fuel pressure. It is not PSI, but MPa. The fuel pressure is measured by the YDS @ the fuel pressure sensor, which I really don't know where it is located (probably @ the high pressure pump). The operating spec calls for 5.0 +/- 0.8 MPa which would suggest that it is in spec.
Thanks for your help & thoughts."
 
"Hello JIT,
I am not sure a

"Hello JIT,
I am not sure about the dual plugs. If you mean plugs w/the dual electrodes, then yes. Again, the engine ran fine all of last year in its present configuration. I talked w/Jeff @ Yamaha. He was very nice and supportive as best as he could be given that I am not a dealer. First, he stated that the 6550 hours runtime on the ECM is a known problem for which there is no fix short of swapping out the ECM. This should not affect the engine operation however. His recommendation is to synchronize the throttle valves. There is an update to the service manual that I do not have and he is going to fax me the update when he finds it. So, I will give it a shot.
At least I am learning a lot.
Many thanks"
 
"Well, still trying to diagnos

"Well, still trying to diagnose this problem. The engine still stalls when advancing the throttle in neutral and I cannot get more than 4200 RPM @ WOT. The weather has not been cooperating for me to "link and synch" the throttle valves. I did take her out for a brief spin yesterday and observed something intersting in the fuel flow: the port (problem) engine is using a significant more fuel at all throttle settings. For example: 2700 RPM, port: 6.1GPH, stbd: 5.2GPH. At 4000 RPM, port: 30.2GPH, stbd: 24.1GPH. So something isn't right and I doubt that it is the fuel pumps or filters. Anybody have any ideas? Many thanks."
 
Hello JIT. I hope that all is

Hello JIT. I hope that all is well.
I don't see how it can be the low pressure fuel pumps as I rebuilt them. The engine is pulling more fuel per RPM than the stbd one. I am wondering if I have an intake problem or something else.
 
"Hello JIT and thanks for the

"Hello JIT and thanks for the reply.
OK, I give. Which pump? The 2 low pressure pumps or the electric in the VST? Sorry to be somewhat thick on this.
My thanks."
 
"OK. Before I tackle them aga

"OK. Before I tackle them again, I'll run the YDS and see what pressures are being logged at different throttle settings. This sure beats the heck out of me. When I changed out the diaphrams on the pumps, the old ones looked good (no fatigue or obvious holes....I inspected them with a backlight). I have ordered a new high pressure filter (the one from the VST to the HP pump). If the weather cooperates I also want to pull the plugs to see if there is anything. I love these engines, but boy are they complicated!"
 
I would also look that the tim

I would also look that the timing. Retarded timing can cause low power and poor fuel economy (using more fuel to make power). Remember to start with the simple things.
 
"Ohhhh<[img]"http://www.marine

"Ohhhh
smile.gif
"
 
"Guess that I need to go to sc

"Guess that I need to go to school on these beasts. Here's the YDS info. It lists timing which looks like could be adjusted. But at this point, I am willing to say: "What the h$&& do I know?"<center><table border=1><tr><td>http://www.marineengine.com/discus/icons/attachment_icon.gif""" align=left alt=""application/octet-stream"">YDS_July_1
[url=""][b]July_1_2008_Port_Engine.xls[/b][/url] (28.7 k)</td></tr></table></center>"
 
"well it is controlled by the

"well it is controlled by the engine sensors

the ecm,tps and a couple more i believe

i need to read up on it again"
 
Back
Top