Hard Starting and dies at wot

[stevo123]

I have a 2007 volvo penta 4.3 GL-E. Was running fine at the end of last season.
When I tried to fire it up for the first time this season, it was hard starting -- but I was able to get it going.

After getting it started, when I took the boat out, it ran fine at low and medium rpms. But, when I tried going wide open throttle, the engine died -- and was hard to start again (I had to wait about 10 minute to finally get it going again -- it was hard to start).

After this happened initially, I did the following --
1) pulled fuel filter (installed when I winterized last year) and poured gas into glass to see if there is water in fuel. Didn't see any separation.
2) changed coil
3) changed spark plugs

I then took it to a local boatyard. They said the carb likely needed rebuilding. But after getting the engine started (they had a hard time), they said the carb looked fine and said new dist cap and rotor would likely fix the problem.

4) So, I installed a new distributor cap and rotor (I was skeptical this would solve the problem -- I had already cleaned/inspected the old dist and rotor).

When I put the boat in the water today, I still have the same hard starting problem.

Anyone have a suggestion (my guess now is that it could be the gas -- I left the tank full last October).

 

[alldodge]

I'm thinking a fuel issue, but need to do some testing to find out.

When it dies, remove the flame arrestor and while looking down the carb (safely) have someone pump the throttle to see if there is any fuel being jetted in.

When cranking, does the fuel pump run (listen, feel)?
If pump is not running when cranking, check for 12V on the yellow/red wire when cranking?
If pump does run when cranking, check fuel pressure (3to7 psi)

 

[stevo123]

Thanks Alldodge!!


I will go out and see if fuel still gets pumped into the carb after the engine dies at wot.

I believe the fuel pump is working because when I try to start the engine -- eventually it smells like it is flooded (and then, after a few more minutes, it will start). However, if I'm wrong, where do I probe the yellow/red wire with my multi-meter when cranking? At the pump, or at the relay?

Also, is there an easy way (is there a meter to purchase) to determine fuel pressure when cranking?

 

[alldodge]

eventually it smells like it is flooded

Need to tell us all about the issues and not leave things out. The flooding issue changes things, its not a fuel pump problem. With flooding at WOT or any other time, its a carb problem. Carb needs to be opened up, cleaned and rebuilt.

Now if it only smells like flooding and this is because its not get spark then its an electrical problem. Need to find out which it is

 

[alldodge]

When it dies at WOT, look down the carb and see if its all wet with gas, as in flooding

If its not flooding, then need to check for 12V on the plus side of the coil.
If 12V is present, then check for spark

 

[stevo123]

I apologize for not providing full details in initial post (and appreciate your recommendations).

I already replaced the coil (as a first step -- when I also checked the gas in the fuel filter for water)-- the coil I replaced was only about 1.5 years old (but they are pretty inexpensive). It didn't solve the hard starting issue.

You've led me to think it is a carb issue -- which is what the boatyard predicted initially. Though, after inspection, they said they saw "no leaks" and said the boat needed a tune-up (but they obviously could not have check the floats).

Is the possibility low that it is bad gas?

 

[alldodge]

Is the possibility low that it is bad gas?

Hard starting and rough running, possibility
Dying at WOT I don't think so

Does it die quick, like turning the key off, or sort of slow die?

 

[stevo123]

At WOT it starts bogging down and then dies (it only takes a couple of seconds to shut down) -- and is then hard again to restart.

At 3,000 rpms (or lower) once started, the engine runs fine. It's just when I open it up that it dies (once it's running).

 

[alldodge]

I would check fuel pressure first

Get carb Tee fitting, or get some fittings and fuel line to make up a Tee fitting so a gauge can be attached between pump and carb. Then get a vacuum fuel pump tester and record pressure readings at all rpm levels.



https://www.amazon.com/Carburetor-Va...14676128&psc=1

 

[willie6979]

Had the same thing happen with my boat! 2k later and finally figured out the good folks over at the Volvo plant dip the entire pump assembly in paint and the ethanol in our gas eats that paint! You can take the fuel filter off and look up in or take pic with phone, if paint is wrinkled up that’s your problem. I found a guy in Michigan that media blasts the assembly and referbs them at good price! Google man cave mechanic and you’ll see it.