navman fuel flow transducer issues

[tae4551]

got it fitted on a 60 yamaha 4 stroke. it works at idle and in a low rev range but when i get her up and sit on 4500 revs she drops down to tell me i am only using 0.02 l/h. anyone else had a problem like this. have i installed it wrong or could it be faulty.

[Spaniard_King]

a couple of points.

do you have it installed between the engine and a water seperator/fuel filter???

is the transducer mounted verticle and do you have the flow correct as per the book??

Sounds like you have it upside down??

[tae4551]

it's installed between the 2. mounted verticle. it's not upside down. not sure about the flow will double check.

[tae4551]

i double checked everything. disconnected it all. set it all back up. does not work. disconected it and blew in it very softly read perfectly. blew harder it read higher. reconnected it and it read nothing. pumped the fuel and it read. had the engine running at 3500 for about 10 mins still read nothing. setup exactly the same as my mates boat and works fine.

[gofishin]

Sounds like noise/interference. Works while the donk is not running, but not while it is running - assuming fuel flow directions are correct as you say.

Remove the T/D cable from where you have it now & just run it across the floor & plug in to the head, if still no good remove the head & power from a separate battery (not being charged by the donk), if still no good plug the head in to your mates T/D & vice versa. Eventually you will find the problem
cheers

[tae4551]

i will have a look at that but i can't see it being noise or interference because can get it to read while running by pumping the fuel bulb and the cable it self runs seperatly from all other wires. it was working fine when i put it in. just stopped on the way home.

[gofishin]

Ah ha
...it was working fine when i put it in. just stopped on the way home. That does make a difference to the diagnosis.

Sounds is if you are getting a vapour/air lock at the T/D (which will stop the paddle wheel spinning). Is it mounted vertical with the flow going upwards? i.e. the cable is coming out at the top (from memory) of the T/D as you look at it? This means, hose outlet from the filter runing is some configuration so that it connects to the bottom of the T/D, and then hose runs out of T/D at the top, and round/down (??) to the motor etc.

Otherwise you may have a dodgy T/D.
cheers

[tae4551]

yep exactly as you described. i am just wondering if the motors are to small for it. it's doing my head in.