volvo penta 5.7 missin power Im out of ideas can anyone help

dukeschuff · **Joined:** Sun May 10, 2009 7:20 pm **Posts:** 15

there are ports on the fuel rails to check pressure
what type of tool is needed for this and where can i get it
will a tire guage work?

dukeschuff · **Joined:** Sun May 10, 2009 7:20 pm **Posts:** 15

well the fuel seems to be ok pressure, borowed buddies pressure tester

ric · **Posted:** Sat Jun 11, 2011 10:47 am

Do this:

http://www.howstuffinmycarworks.com/GM_ ... ssure.html

TX H210SS · **Joined:** Thu May 27, 2010 9:10 am **Posts:** 1488

trying simple approach - have you loosened the fuel cap to make sure it's not a vacuum issue due to clogged vent line. damn dirt dobbers....

You mentioned running it on fresh can of gas??? do you mean as a bypass to the fuel tank? Did you have it stored with unstablized fuel? If so, i bet ethanol gunk is your issue....if thats the case you need a fuel system overhaul....hard to clean that crap out of the system.....ethonal is a pain in the gass

dukeschuff · **Joined:** Sun May 10, 2009 7:20 pm **Posts:** 15

yes, tried removing the vent line entirely, did not change, and the problem remained while running it off a fresh tank of fuel for at least 1 gallons worth (i removed the hose feeding the engine from the fuel tank and put it in a 5 gal gas can with new gas)

** i did however notice that there was not much in the way of suction from the hose but when i pulled it out of the gas, eventually i began to hear the whine of the high pressure pump starving for fuel, so i know it is working but should it be stronger perhaps?

acguy · **Posted:** Sun Jun 12, 2011 9:08 am

I had a similar problem 3 years ago with my sundowner. Changed cap rotor full tune up. I was told by a GM mechanic sometimes the engines won't fire right with different plugs. FWIW I bought new AC Delco (GM plugs) and my problem went away. I had NGK plugs in them and had gaped them before I put them in.

Good Luck

ric · **Posted:** Sun Jun 12, 2011 9:33 am

acguy wrote:

I had a similar problem 3 years ago with my sundowner. Changed cap rotor full tune up. I was told by a GM mechanic sometimes the engines won't fire right with different plugs. FWIW I bought new AC Delco (GM plugs) and my problem went away. I had NGK plugs in them and had gaped them before I put them in.

Good Luck

NGK are too high of a quality for crappy american coil packs LOL.

Oh another note, just because a fuel pump "works" doesn't mean it's really working. Just like a water pump. You need to diagnose better with a fuel pressure gauge. You either have a regulator or fuel pump going bad or a massive clog

dukeschuff · **Joined:** Sun May 10, 2009 7:20 pm **Posts:** 15

ok so i tested fuel system
low pressure pump putting out about 6psi, delivering plenty of fuel to resevoir
high pressure pump running at 30 psi
the system did not hold that pressure once the engine was stopped, not sure if this is normal

ric · **Posted:** Mon Jun 13, 2011 8:33 am

dukeschuff wrote:

ok so i tested fuel system
low pressure pump putting out about 6psi, delivering plenty of fuel to resevoir
high pressure pump running at 30 psi
the system did not hold that pressure once the engine was stopped, not sure if this is normal

Bad fuel pressure regulator

dukeschuff · **Joined:** Sun May 10, 2009 7:20 pm **Posts:** 15

not the regulator son of a!!!! wtf

dukeschuff · **Joined:** Sun May 10, 2009 7:20 pm **Posts:** 15

so the boat mechanic spent 16 hours figuring out that the exhaust flapper broke loose and was clogging the exhaust. he charged me for 6. what a nice guy. boat runs better than ever thanks to all the tune up stuff i did. thanks to all who helped me. eric

www.iFourWinns.com

volvo penta 5.7 missin power Im out of ideas can anyone help

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