2004 Volvo Penta 5.0 Gxi will not start

[bobtylerjr]

Starting problem on 2004 5.0 Gxi and hoping there is someone who will be able to help.

I have a 2004 Sunesta 236, recently purchased used. Ran fine for about ten hours,without issue. Would not start on last attempt to go boating. I had both batteries tested and replaced with new 1000 CCA Interstates. I have bypassed the kill switch behind the cockpit panel (temporary to isolate the problem). I located and checked one 50 amp circuit breaker (located on back, stern side, of engine). The breaker did not feel "popped" when I checked it. I checked all fuses in the fuse and relay box on the top of the engine. I checked all circuit breakers behind dash, although none appear to even be potentially related. No breakers behind the dash were "popped". The boat has ample fuel. The fuel pumps make a noise as if they are running normally when I turn the ignition key to the first detent. I consistently get the alarm sound when I rotate the key to the first detent as well.

I am at a loss except to start replacing parts, call a mobile repair or take the boat to a dealer. I am reasonably capable of swapping parts and mechanical work but I am out of ideas in terms of further diagnosing the problem. Any help would be greatly appreciated.

Thank you!

 

[Bondo]

Ayuh,..... Welcome Aboard,....... Is the motor crankin' over on the starter, 'n not firin',..??

Or is the motor doin' Nothin', when ya turn the key,..??

 

[bobtylerjr]

Hello Bondo. The motor turns strong, sounds like it wants to start but doesn't actually start/run.

 

[NoExcuses]

You said that you checked the fuses in the fuse box but did you also try swapping the relays? Sometimes just pulling them out and reinserting them will correct a starting problem on this engine. The box itself can also fail but I'm not sure how to troubleshoot a faulty box, I was able to swap boxes between my two engines to isolate the failure. There is a Volvo SB out there that says fuse/relay boxes can fail due to engine vibration, the replacement comes with vibration isolator bushings to extend service life. Google Volvo Service Bulletin P-37-2 2 01 for the document.

 

[Bondo]

The motor turns strong, sounds like it wants to start but doesn't actually start/run.

Ayuh,.... Then check to See if there's Spark,....

Pull the flame arrester, 'n See if there's Gas,......

 

[bobtylerjr]

I know where the flame arrester is and how to remove it. Can you be a little more descriptive when you say "see if there is gas"?

Thank you

 

[Bondo]

Ayuh,... I don't do Volvos, so is this a throttle body Efi, or a multi-port Efi,..??

With a throttle body injection, you can see the gas squirtin' into the intake, when crankin' the motor,....

If a multi-port Efi, there should be a schrader(sp) valve for testin' fuel pressure on the fuel rail,....

 

[bobtylerjr]

There is a throttle body under the suppressor. Not sure about other details regarding type of injection

 

[StingrayMike]

Had a similar problem and replaced throttle position sensor, and that fixed my issue

 

[alldodge]

There is a throttle body under the suppressor. Not sure about other details regarding type of injection

With the arrestor off, put some safety glasses on, then crank the engine over while looking at the injector nozzles. There should be some gas spraying out the bottom of them. If you see gas then go and check for spark at the coil. If you don't see gas, pour a couple ounces of gas down the throttle body and crank it over to see if it hits

 

[bobtylerjr]

Thank you. I will check the throttle body out today and use carb cleaner and let you know how it goes.

 

[bobtylerjr]

Just attempted to start using staring fluid. The engine turns strong and there was one significant "pop" but no start/run at all. I am going to make another attempt in a few moments just to confirm.

I wanted to clarify that I am adding the starting fluid correctly to the throttle body... The throat with the hinged valve is closed when I add two brief shots of starting fluid. I attempted to gently rotate it, using very little force by pushing on one side, the valve open and it would not move so I stopped. I was not sure if the starting fluid needs to be in the open throat or if simply adding a couple shots (sprays) of the fluid to the closed throat would suffice. After the start attempt that resulted in one "pop", the throat was closed and wet but not soaked. Sorry for all the detail but I am trying to be as descriptive as possible since I cannot show you video and to avoid confusion.

I will let you know how my next attempt goes shortly. Thank you.

 

[bobtylerjr]

Second attempt to start using starting fluid... I opened the throat of the throttle body using the power lever at the helm, sprayed two good shots of fluid into the open throat, returned the power lever to the neutral position (closing throat) and attempted to start. The result was no start/run or "pop". I will now check the spark and report back.

 

[alldodge]

So far your doing it correctly.

 

[bobtylerjr]

I checked the spark by removing one wire, inserting a screwdriver in the end of the wire, holding it against the exhaust manifold and observing the spark. The spark appeared blue and strong.

So to recap... fuel pumps are heard operating when the ignition key is turned to the first detent, all breakers, fuses and (as best as I can tell) relays are in order (not blown, popped, or malfunctioning). Adding starting fluid to the throttle body, as mentioned in my recent posts, had no effect.

Any other thoughts?

Thank you.

 

[alldodge]

My first thought is your not getting fuel. you sprayed either down the throttle body and got one pop. When doing it the next time you got nothing. My thought is your not using much either (that part is good), but on the other side either evaporates quickly. Sounds like there is only you to work on the boat.

Find a cap about the size of what sits on top a WD40 can. Put some gas in it about half. Take that gas and pour in down the throttle body, little on both sides. Then crank it over.

If after this it does not fire, get a piece of fuel line about 3 to 4 feet. Remove the fuel line going to the throttle body and attach the fuel line. The other end of the fuel line place in a gas can. Now turn the key to ON and see if you get any fuel coming out of the line into the can.

If you get fuel pumping your going to need to get a fuel pressure gauge that can read up to 60 PSI.

 

[bobtylerjr]

Update after weather and work schedule delays.... The problem was fouled spark plugs. Thank you for all of the responses and good advice!