Logo
FULL SITE MENU

Fuel pump under a load

B

bobbyj202

Guest
"350 mag, carb, mechanical fue

"350 mag, carb, mechanical fuel pump.. boat starts and idles fine, revs great in nuetral, even runs fine at slow speeds. push the throttle down it takes off and then boggs down and sometimes stalls. this is intermittent, does not happen the same way twice. sometimes i get on plane and its fine then it takes a dump. after it boggs down its clearly not on all 8 cyliders then meracliuosly it with go right back on all 8 and run fine for a few then start this crap all over.. I am thinking fuel pump is getting weak or something, definetly thinking its fuel related because it starts and idles perfect and runs decent then all of a sudden its sh*t.."
 
"Fuel fitler is brand-new, plu

"Fuel fitler is brand-new, plugs new, carb tore apart checked and cleaned. fuel syphoned, tank inspected and refilled with premium.. even threw a coil at it just for the hell of it.. I got the new fuel pump today, they had to order it. I will put it in tomorrow.. I did take off the old pump just to take it apart and inspect but nothing obvious, just a little crud that i cleaned out and the diaphram doesnt look great but not too bad. is it possible that the pump cant keep up under a load? maybe its on its way out?? Seems like when the throttle increases the engine starves and boggs down and the fuel cant keep up.."
 
"Just wondering how this turns

"Just wondering how this turns out because I am having a similar problem with my mercruiser 898 (chevy 305). Mine is with the mechanic right now but this has been an ongoing problem. I also think mine is a fuel delivery problem most likely the pump. If you don't mind post here or shoot me an email at [email protected]"
 
"Its intermitient and i am get

"Its intermitient and i am getting frustrated because this boat runs so good except this stupid problem. starts, idles, revs and slow speeds it fine (perfect) i can get on plane then it goes aways then boggs me down to a complete stop then somtimes stalls. starts right back up and runs fine.. ???????? I am going to shoot at it soon with my Sig. If this pump doesnt work I am rebuilding the carb.. it only happens under a load and when it feels like crapping out, not all the time and never the same way twice????????????????? Hard to pin point and I hate throwing parts at engines........"
 
"If the pump swap doesn't

"If the pump swap doesn't help, here's what's left that comes to mind:
anti-syphon valve
fuel tank vent clogged with critters, mud wasps, etc.
you can isolate these by temporarily plumbing in an outboard tankto feed the pump.

Was there any crud noticable when you emptied the tank?"
 
"I am taking that advice on th

"I am taking that advice on the external tank tomorrow. I got a brand-new 5 gal tank and i am running a line right to the new pump, yea the new pump and still runs like sh*t... Probably water or some other crap in the tank like orgianlly suspected but i did syphon all the gas out and put all new in it.. ran fine for a day or two then right back to sh*t."
 
"if the 'new' tank wor

"if the 'new' tank works, you know where the problem lives. For what its worth, the few tanks I've clean really didn't have any crud removed by the syphoning step. The all required some mechanical or chemical help, along with a 'high volume' approach to remove the crud while it was suspended.

Is the fuel tank built in? if yes, what is it made of and how old?"
 
"forgot to post this because i

"forgot to post this because i had a few running about this issue.. i removed the tank, had cleaned by a radiator shop, put new gas in it and it is totaly back to normal now..there was a bunch of black sh*t floating around and also on the bottom of the tank. couldnt really see all this until the tank was removed because its buried in the boat..
thanks guys"
 
Back
Top