2007 Yamaha F200TXR Fuel Issue

dwfman

Recruit
Joined
Jun 21, 2011
Messages
1
HI, I'm hoping someone in the forum can steer me in the right direction to solve this issue, I'm ready to pull out what little hair I have left. Problem started with corroded fuel cooler that leaked seawater into the fuel system while boat sitting for a couple of months. Replaced cooler, cleaned VST and HP pump filter, replaced all other on-board filters and the fuel/water separator on the boat. I installed new fuel injectors and replaced the spark plugs. The fuel rail pressure is running about 43psi while cranking and holds about 40 psi for quite sometime ignition off. The injectors have power ignition on and receive a ground signal while cranking. I have run through all the sensor checks in the Yamaha manual; coils, spark, relay, etc. The motor will run if I spray propane in the intakes so the ignition system, compression and valve train seems ok. It appears the injectors aren't doing their job despite having the required signals and fuel psi. I have checked the flow through the schrader valve on the fuel rail while cranking. It flows about 4oz before the hp pump shuts down.

Any input would be greatly appreciated
 

alldodge

Supreme Mariner
Joined
Mar 8, 2009
Messages
31,490
Not a Tam or OB guy, but most all work from the same principlies. A ground is applied to the injectors by the ECM to fire. The ground happens after the ECM gets a signal from the distributor (or other type control) which tells the ECM there is spark. The ground signal cannot be seen with a voltmeter, its can be done with a NOID light.
 

Clawtooth

Cadet
Joined
Nov 30, 2019
Messages
21
I have absolutely no knowledge of that engine, but I would try to visually check for the injectors to spray. I remember seeing this video a while back so I went back and found the url for it. It is showing them cleaning the injectors on a Yamaha. I know you replaced yours but maybe this will give you an idea on how to check to see if they are actually spraying fuel when they get the signal.
 
Last edited:
Top