Fuel Pump Replacement- Remeasured Pressure

[FreeBeeTony]

Re: Fuel Pump Replacement- Remeasured Pressure

I am going to try to get a better pressure gauge and make arrangements to take it out of the water.

 

[Buttanic]

Re: Fuel Pump Replacement- Remeasured Pressure

Just because the carburator is new doesn't mean debris that might have been in the old pump or line didn't make its way to the filter in the new carb. Also is the line from the pump to the carb rubber or metal and if it is rubber is it marine grade. I have seen cheap rubber fuel line deteriorate and plug up the filter at the carb as fast as you clean them.<br />The golden rule of trouble shooting is always check the easy and simple things first.

 

[FreeBeeTony]

Re: Fuel Pump Replacement- Remeasured Pressure

Its a Weber/Edelbrock carb. The filter is actually on the inside at the needles.<br /><br />The line from the pump to the carb is metal.

 

[FreeBeeTony]

Re: Fuel Pump Replacement- Remeasured Pressure

I know this is going to sound unbelievable but.......I bought a lower pressure gauge and remeasured the fuel pressure tonight. It started around 10lbs at idle and went to ~8-9lbs at higher RPM's. Could my fuel pressure be too high?<br />Is there a pressure regulator I could install?

 

[steve n carol]

Re: Fuel Pump Replacement- Remeasured Pressure

We used to use in-line pressure regulators on our street cars. The idea was to maintain an even pressure, typ. 5-7 lbs, therefore a constant float bowl level, and not worry about pushing fuel past the needle/seat valve. I never saw the real need for it...sl

 

[Reel Poor]

Re: Fuel Pump Replacement- Remeasured Pressure

Tony <br />If the carb is not flooding with gas dont worry about it right now. With this kind of pressure you can probably rule out a lean condition. <br /><br />After making this statement I got to thinking.<br />While running at the point of bogging have you tried to choke the carb? While on your way to pull the boat out of the water to check exhaust, try closing the choke flap VEEERRRRY slowly/small increments to see if the engine will respond to a richer fuel mixture. If it boggs worse, its not lean, if it tries to pickup rpms it may be lean.<br /><br />I added this because you posted this;

FreeBeeTony <br />Member # 9625 posted July 17, 2005 01:43 PM<br />--------------------------------------------------------------------------------<br /> Well it shows some improvement but still not 100%.<br />I can get to ~3500RPM's now...........

If this has no or an ill effect see below. <br /><br />

originally posted by several people<br /><br />Its time to get the boat out of the water, pull the drive, and check for an exhaust restriction.

 

[Don S]

Re: Fuel Pump Replacement- Remeasured Pressure

For information on what has been checked, tested, replaced, bypassed, discussed, cussed, and rejectected here's the links to previous posts regarding this problem.<br /><br />Fuel Pump Replacement<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012790 <br />Newest.......<br /><br />CARB REPLACEMENT DIDN'T WORK- I THINK I FOUND SOMETHING<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012403 <br />95 replies<br /><br />Carb Replacement- Edelbrock- I did it! <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012361 <br />21 replies<br /><br />Thunderbolt IV ignition Module- ONLY 1 THING LEFT <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012276 <br />5 replies<br /><br />Thunderbolt IV Spark Advance <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012179 <br />14 replies<br /><br />350 Mag Still Bogging Down <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011975 <br />59 replies<br /><br />Thunderbolt Ignition Module<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=012196 <br />2 replies<br /><br />Timing Specs <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011924 <br />5 replies<br /><br />Carb Rebuild <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011882 <br />22 replies<br /><br />Don S.link to Merc Manual<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011795 <br />19 replies<br /><br />Time for Compression Check UPDATE <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011822 <br />16 replies<br /><br />5.7L Mercruiser Update <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011729 <br />4 replies<br /><br /><br />Spark Plugs for '92 350 Mercruiser Magnum <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011790 <br />1 reply<br /><br />5.7L Mercruiser test drive<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011616 <br />26 replies<br /><br />Checking Compression<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=011621 <br />5 replies

 

[FreeBeeTony]

Re: Fuel Pump Replacement- Remeasured Pressure

Thanks for organizing my work Don...........

 

[imported_scott_m]

Re: Fuel Pump Replacement- Remeasured Pressure

I thought these carbs typically like 4-6 PSI of pressure...any more than that and you're blowing the needles off the seats thereby creating a rich condition. Have you looked down the throats while running to make sure there is a nice fine mist of fuel going down there?

 

[FreeBeeTony]

Re: Fuel Pump Replacement- Remeasured Pressure

If I was blowing past the seats......would it idle ok?