2001 Challenger 240 merc dies off idle

[younamesales]

Ok I need some help, I'm tired of throwing parts at this thing. So far I've changed the vacuum operated fuel pump and the high flow fuel pump, sent out the injectors to be cleaned and checked and changed all the filters.
The boat idles great and will accelerate 500 rpm above idle, but after that the engine falls on its face and stalls unless I quickly bring the throttle back down to idle and then the motor will stay running at idle. It's almost like the motor is not getting enough fuel.

The only thing I have gained since I have changed the parts is the consistent 500 rpm above idle, and for the first 30 seconds of the ride I got the boat up on plane and it was acting normal. Before the parts were changed. I could only get the rpm to go up if I would snap the throttle, but it would fall on its face immediately after that and stall. Its almost like it starves itself under a load. Any Ideas?

 

[younamesales]

the tps reads .223v at idle and 7.70v at full throttle. all electrical sensors are also in spec.

 

[Dr Honda]

There is NEVER a reason to "Throw parts at the boat". Figure out the issue, and fix it.

First... those pulse pumps rarely go bad. New is good... but did you test your old one?


Yes... to me, it sounds like it's not supplying enough fuel. So... check the pressure on the fuel regulator. You should be seeing 36 (ish) pounds of pressure. It's an easy test... put it in the water, with a gauge... and run up the throttle. If the pressure drops... that's the issue. but if it stays up... there is a problem elsewise.


Have you dug around the helm for a throttle guardian? They suck, and cause WAY TOO MANY ISSUES !!! Find it, and destroy it ! (lol)


Check those, and we will move forward.

 

[younamesales]

fixed the problem! It was the low pressure electric lift fuel pump.