(300x).
Which one is the fuel pump, the square box that mounts to the side of the motor that the manual calls a fuel pump or the pump in the vst, or both?
Can i install an in dash fuel pressure gauge and if so does it operate off the tester nipple at the bottom of the fuel rail?
I have analog trim gauges as well as the trim display on the smartcraft, neither of which work. Where is the sending unit located and how do I get it to work?
Thank.
Both are fuel pumps. The small square one you refer too is a low pressure diaphragm fuel pump. It runs off of air pulses from the engine to work the diaphragm. That pump supplies fuel to the VST. Then the VST has a high pressure fuel pump inside of it that pumps the fuel into the fuel rail. The shrader valve (nipple you mentioned) on the VST is where you hook up a fuel pressure guage to check the pressure.
On the trim sender. If you have one it should be on the mounting clamp of the motor. Wait for Don to confirm because I'm not 100% sure, but I think the 300x's had two different style mounting clamps. And I think one type didn't have an integral trim sender on it. Again, not 100% on that.
Modified by db_db at 6:16 PM 1/23/2012
"Give a man a fish and feed him for a day...teach a man to fish and, he'll lay out of work, miss dinner dates with the wife....and live happily ever after"
"He, who dies with the most toys, wins"
Thanks for the reply. I do not have any external trim sender that i can find.
I know I can check the fuel pressure from the valve but I am wondering if I can install a gauge to permeantly mount on the dash display? I would like to be able to monitor the pressure to assist in trouble shooting as well as to help catch a potential problem.
I don't see why you couldn't. It's there for monitoring the pressure. You need to make sure it has a good seal though so no leaks develop. I'm sure Don will discuss it here once he gets on here in the AM.
"Give a man a fish and feed him for a day...teach a man to fish and, he'll lay out of work, miss dinner dates with the wife....and live happily ever after"
"He, who dies with the most toys, wins"
Jonesy:
You could certainly add a monitoring device to this test port. As stated, it's IMPERITIVE that no leaks be present, however. Due to the distance between you dash and the fuel rail, it would be preferable to utilize a sending device, and an electronic gauge (dash mounted)... there are several relatively suitable versions available across the internet for this purpose.
The above descriptions of the fuel pumps are good explanations.
To assist further with the trim sender, it would be necessary to have the serial number of the engine in question (to confirm whether you have integral or offshore trim system/midsection).
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