help help help does anyone know about yamaha 225 ox66 ecu controling the ground

some one out here has to know or heard of my issue. again its a 1999 225 yamaha ox66 vmax fuel injected.i have replaced all 3 Lp pumps pulled and cleaned the vst tank and mesh filter.i have pulled and cleaned the o2 sensor.ran motor on seperate fuel tank with can of seafoam when i could get it to run for more than 30 seconds.i have found now with the key on the pump is on for 3-5 seconds the motor will start runs for about 15-20 seconds then acts like it runs out of fuel. what we found is the ground loop is not closing to keep the fuel pump running.the ecu is holding out the ground.can anyone help lead me in the right direction to look for the issue. thanks again for any responce to my issue.

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

Is there a reason you keep starting new threads on the same topic? all 4 with the same info!

Have you read your service manual or do you even have one for your motor?

Have you searched the forums for info?

What on you motor tells the ecu that the motor is turning over or running? If the ecu does not think the motor is running it will not keep the pump running

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

99yam40 said:

Is there a reason you keep starting new threads on the same topic? all 4 with the same info!

Click to expand...

Well . . . I am guessing since there are no replies to those other threads

Welcome aboard dieseltruck!! If you want your thread to get more attention simply post a "Bump ^^^" as a reply to your own thread and people will notice you still need help. I am going to delete those other three threads so there is focus only here. Good luck with this!!

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

i do not have a manual sorry. im new to this and sorry for the same thread i was not sure if they stay on day to day. i have read many post on here and yes many have been very useful and has gotten me this far.sometimes it will run but not for a long time i read a post that rodbolt said if the ecu does not sense the pulsers it will drop out the ground to the fuel pump. with the key on it buzzzes for 3-5 sec the motor will start runs for 15-30 seconds then acts like it runs out of gas. checked when motor was running there was no 12 volts at fuel pump. there was 12 volts to ground.so i used a jumper when the motor started to stall i grounded the fuel pump and the motor picked rite up and ideled fine.so for some reason the ecu is not sensing the motor running so its droping the ground.thank you for your respond and sorry again for the threads im new and will learn how to use this sight. would like someone to try to lead me to check something they may know about on my issue.

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

thank you im very sorry like i said will learn how to surf around this place and thanks again for your responce

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

No problem, you will learn. Best to read the top stickies and see what to do.
If Rod said to check pulsers for your model motor then that is where I would start.

The best thing to do is get a service manual for your motor so you know what to do and what equipment to use to test things

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

thank you for your responce again. i saw a post that said ecu ground path is through the resistor mounted above the throttle body and is controled by the pulser coil signal with out that sinnal the ecu drops out thr ground to the pump. sometimes it runs for awhile then dies do you think the ecu may have a bad ground? i know i need to get a manual but like most people money is tight so im trying to fix on my owne.

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

you really need a manual if you are going to work on this thing yourself.
If the ecu had a bad ground then it would not turn it on at all, is my thoughts

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

well i think we have it down to the pulser coils,the resistor,or the black relay i dont have the dionostic tools to see witch is causing this issue.was really hoping someone on here has ran into the same issue and was able to help me out. im gonna have to break down and have a tech take a look at it....thanks yam was also hoping rodbolt seen my post and could help me out i see he is a busy man on here.. thank you for your help..

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

Rod has not posted here for a few months. Some one may have the manual and specs, but I do not have either one.
You will still need to test with the proper equipment, which is probably just a meter and a DVA adapter for the pulsers and just a meter to check resister and relay

Re: help help help does anyone know about yamaha 225 ox66 ecu controling the ground

I am fighting the same condition on my 2003 225. In my case the fuel pump isn't getting 12 V to the fuel pump. The pump should run with the ignition on and lanyard in place, neutral. I am checking the voltage at the fuse (5 amp) brown case on the port, front, top of the motor.

I understand the ECU will drop ground to the pump if it thinks the engine is not running.

Here is a thread from another forum that has a wiring diagram
http://www.thehulltruth.com/boating-forum/232243-yamaha-f225-wont-start.html