Unable to reach wot don't know what else to do.

jimedac

Seaman
Joined
Sep 19, 2010
Messages
50
I have been trying to resolve a problem which started shortly after changing spark plugs. I cannot seem to rev past 3000 rpms I used to get 4200 rpms.
I have a 1995 volvo penta 5.8fihu
Here is what i have done.

1.) changed plugs twice I now have the same type plugs as original.
2.) Set my gap at .045 per engine
3.) changed iginition wires.
4.) changed distributor cap
5.)changed rotor
6.) changed thermostat
7.)fuel filter
8.) tested fuel system 39 psi high pressure, 4 psi approximately low pressure,
2 in Hg suction.
9.) continuity checked TP sensor
10.) A friend checked for codes with his OTC auto tester no codes found.
11.) checked my slow circuit it is fine although i went ahead and changed the oil press switch
12.) I am going to try my spare prop next

any other ideas would be appreciated

thanks

jimedac
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: Unable to reach wot don't know what else to do.

Check your firing order. Make sure you know which cylinder on your motor is #1 and how they're numbered. Fords are NOT the same as GM's ....
 

jimedac

Seaman
Joined
Sep 19, 2010
Messages
50
Re: Unable to reach wot don't know what else to do.

45auto thanks for responding I have checked the firing order several times
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,344
Re: Unable to reach wot don't know what else to do.

compression test results? Fuel contaminated with too much ethanol. Get 2 inches of fuel and put a mark and 2 inches of water and put a mark in a container, shake well, How much is floating, the full 2 inches of fuel or somewhat less(ethanol)
 

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: Unable to reach wot don't know what else to do.

Was fuel pressure tested at idle or WOT?
 

kewlkatdady

Petty Officer 2nd Class
Joined
Sep 12, 2010
Messages
188
Re: Unable to reach wot don't know what else to do.

check you oil level....

ifs its really full and milky...well...just check it.
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,072
Re: Unable to reach wot don't know what else to do.

Boat stay in the water?Left with the drain plug in?
Too much of a load?
Putting a different prop on shouldn't make a difference unless it's slipping.Then the RPM's would go way up.
Not sure what fuel system you have but Ethanol is swelling gaskets and making hoses collapse.J
 

jimedac

Seaman
Joined
Sep 19, 2010
Messages
50
Re: Unable to reach wot don't know what else to do.

The boat has fresh gas from the marina. The fuel pressure on the rail is 39 psi wot
Vacum test shows no more than 2 inHG. The prop definitely is nicked on all 3 blades though.
I am going to change the prop and clean the bottom as it has been left in the water for over a month.
I have not done compression test. I want to have a mechanic look at it but he is swamped with winterizing.
He said he can look at it in the spring I also want him to service the drive. I have pretty much exhausted
my abilities and if you ask my wife that happened 2 weeks ago lol. I apreciate all the advice I have received
trying to diagnose this problem though and I have learned a ton and plan to keep learning from the experience
here on iboats. A man needs to know his limitations though.

Thank You All
Jimedac
Jimmy The C.
 
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