Losing fuel pressure- Update Checked compression

akmoosehauler

Petty Officer 3rd Class
Joined
Aug 29, 2007
Messages
78
On a 07 DF140.

Hooked up a fuel pressure gauge and am losing fuel pressure pretty fast.
It gets up to the speced fuel pressure but will not hold it for the speced time.

All hoses and junctions are good and have checked multiple times.

What do i look for and do from here.:redface:

Thanks.

8-13-2011

Checked the compression and here is what i got.

1. 205
2. 185
3. 187
4. 190

Tries to do it how the book says and ran into a little trouble.
It would not let me turn the motor over with the emergency lanyard disconnected.
I had to have it connected.

Did i end up doing it wrong.http://forums.iboats.com/images/smilies/redface.gif
Did it skew the numbers?

Thanks
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: Losing fuel pressure

Re: Losing fuel pressure

If you have the gauge connected to the high side. Fuel pressure regulator in the VST, or an injector/s leaking. High side should hold pressure for 5 minutes.
 

akmoosehauler

Petty Officer 3rd Class
Joined
Aug 29, 2007
Messages
78
Re: Losing fuel pressure

Re: Losing fuel pressure

If you have the gauge connected to the high side. Fuel pressure regulator in the VST, or an injector/s leaking. High side should hold pressure for 5 minutes.

Thanks.
Yes it was hooked to the high side and would lose pressure in less than 2 minutes.
Would this make the motor use fuel like mad.
Currently it's using 15 gph.
 

lakensea

Chief Petty Officer
Joined
Jan 30, 2002
Messages
542
Re: Losing fuel pressure

Re: Losing fuel pressure

Thanks.
Yes it was hooked to the high side and would lose pressure in less than 2 minutes.
Would this make the motor use fuel like mad.
Currently it's using 15 gph.

Is the engine running poorly?

Where are you getting the 15 GPH figure from? Actual usage, fuel flow meter or Suzuki digital data?

What is the fuel pressure throughout the RPM range under load?
 

akmoosehauler

Petty Officer 3rd Class
Joined
Aug 29, 2007
Messages
78
Re: Losing fuel pressure

Re: Losing fuel pressure

Is the engine running poorly?

Where are you getting the 15 GPH figure from? Actual usage, fuel flow meter or Suzuki digital data?

What is the fuel pressure throughout the RPM range under load?

Actual use.
Motor is down on power compared to other DF140's.
I do not know the pressure yet when running. Will test in the near future.
Motor has had fuel in the oil.
Bottom 2 plugs have carboned up.

So far the motor uses more fuel than my old 2-stroke FI 150.

Thanks
 

akmoosehauler

Petty Officer 3rd Class
Joined
Aug 29, 2007
Messages
78
Re: Losing fuel pressure

Re: Losing fuel pressure

Did you check on these?

Checked the injectors today and none of them showed any signs of leaking while the system was under pressure.

Waiting on some $$$ before checking the vst.
But no fuel leak around it.

But while running the motor on garden hose i smelled what was burnt oil.
Also had some smoke but couldn't see the color.

Thanks
 

akmoosehauler

Petty Officer 3rd Class
Joined
Aug 29, 2007
Messages
78
Re: Losing fuel pressure

Re: Losing fuel pressure

Did you find the cause of the fuel contamination in the oil?

No did not find out what has caused it.
Checked the low pressure fuel pump and nothing was leaking out of it and the injectors did not leak.
With a zuk 21 pitch prop i can turn 6000 to 6100 at full throttle.
Thermostat was tested and it was working good.
In the next day or 2 i will get into the vst.

Thanks.
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: Losing fuel pressure

Re: Losing fuel pressure

How did you check the low pressure pump?
What kind of oil you using? Just for my info.
Ever check the valve lash?
The fuel pressure regulator and seals are one of the fuel pressure problems.
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: Losing fuel pressure

Re: Losing fuel pressure

Read all old posts.

What I don`t understand.
Why so hard to to correctly prop the engine?
Why so hard to get on plane?
Down on power==== fuel pressure, spark plugs. You have to repair this.
Engine ever had 100 hour service, where every thing is check with lap top?
O2 feedback system mapping been done?



Compression is within specs.
 

akmoosehauler

Petty Officer 3rd Class
Joined
Aug 29, 2007
Messages
78
Re: Losing fuel pressure

Re: Losing fuel pressure

Read all old posts.

What I don`t understand.
Why so hard to to correctly prop the engine?
Why so hard to get on plane?
Down on power==== fuel pressure, spark plugs. You have to repair this.
Engine ever had 100 hour service, where every thing is check with lap top?
O2 feedback system mapping been done?



Compression is within specs.
Running a good dino 10-40 oil.
Can reach 6100 rpm with a zuk 21 pitch prop.
Motor was sent to dealer and supposedly everything was checked.
Never got a paper detailing what they did though and when i went to get them they could not show me anything.
The head of the outboards did get bent out of shape with me asking.

Am know working with the brand new local dealer on this motor.
They did order a new pressure regulator and i hope i have the money for it when it comes in.

Plugs did look okay after the last run but motor is still using a lot of fuel.

Bit pissed at this motor is my old fi 2-stroke could still get better fuel mileage than the 4-stroke 140.
I know i will not get the power of the 2-stroke 150.
Also it is not getting fuel mileage like other 140's that are on Heavier boats.
Gas is expensive with it sitting right at $6 a gal.

Thanks.

Thanks
 

lakensea

Chief Petty Officer
Joined
Jan 30, 2002
Messages
542
Re: Losing fuel pressure

Re: Losing fuel pressure

How many hours on the engine?
Did you buy it new?
How heavy is the boat?
If you had a fuel pressure problem, the engine would not run to 6100 RPM.
What do you mean by "down on power"?
Are you still getting fuel in the oil?
Have you had a leak down test done?
15GPH - is that at WOT or average cruising?
Does the engine start with a simple turn of the key and run smoothly throughout the entire RPM range?
 

akmoosehauler

Petty Officer 3rd Class
Joined
Aug 29, 2007
Messages
78
Re: Losing fuel pressure

Re: Losing fuel pressure

How many hours on the engine?
Did you buy it new?--Yes
How heavy is the boat?--haven't weighed it but it is a 22ft pacific skiff.
If you had a fuel pressure problem, the engine would not run to 6100 RPM.
What do you mean by "down on power"?--when i get a bit of a load in the boat.
Are you still getting fuel in the oil?--Not in the last 2 trips but i still have to check after the last one.
Have you had a leak down test done?--No don't have the tool yet
15GPH - is that at WOT or average cruising?--Average cruise
Does the engine start with a simple turn of the key and run smoothly throughout the entire RPM range?--starts good but then at idle it will surge a little up/down. It will smoke/smell of oil darn near every time at start up.

I put a lift on the boat to put the motor higher to help with the fuel mileage.
Have to run the motor darn near where it cavitates and the anticav plates is way above the bottom of the boat.
Am also comparing it to other boats with 140's that are heavier and they use less gas plus are a bit faster.

Thanks
 

lakensea

Chief Petty Officer
Joined
Jan 30, 2002
Messages
542
Re: Losing fuel pressure

Re: Losing fuel pressure

I put a lift on the boat to put the motor higher to help with the fuel mileage.
Have to run the motor darn near where it cavitates and the anticav plates is way above the bottom of the boat.
Am also comparing it to other boats with 140's that are heavier and they use less gas plus are a bit faster.

Thanks

Has it been like this since new?

What does your installing/selling dealer say about it (I assume you have had them look at it)?

Have they hooked the engine up to the Suzuki diagnostic laptop while surging at idle to check which cylinder is at fault, and to check the injector "on" time?

You have to have a leak down test done to determine why you are getting smoke at start up - it could be as simple as the cylinder head cover baffle plate not draining properly.

In order to be using that much fuel, you would have to have serious amounts of fuel either in the crankcase or dumping out the exhaust into the water - that engine just is not capable of burning that much fuel and run as well as you state.
 

akmoosehauler

Petty Officer 3rd Class
Joined
Aug 29, 2007
Messages
78
Re: Losing fuel pressure

Re: Losing fuel pressure

Has it been like this since new?--Yes

What does your installing/selling dealer say about it (I assume you have had them look at it)?--Yes sent it in to them and they keep saying bad prop,fuel. The one mechanic has been helpful and cannot believe what is happening with this motor. The head mechanic has been nothing but trouble.

Have they hooked the engine up to the Suzuki diagnostic laptop while surging at idle to check which cylinder is at fault, and to check the injector "on" time? The dealer i bought it from did hook it up and only told me about the 2 overheat that i had. They happened after chewing through mud to get out of the boat harbor.
They did not run the motor though even in a run tank.
They never gave me anything on paper or otherwise of what the did to the motor.
Just what they told me.
Will give the local dealer a try after i get some more money as things are really tight.

You have to have a leak down test done to determine why you are getting smoke at start up - it could be as simple as the cylinder head cover baffle plate not draining properly.--Will try and do it when i have the tools or have the local dealer do it.

In order to be using that much fuel, you would have to have serious amounts of fuel either in the crankcase or dumping out the exhaust into the water - that engine just is not capable of burning that much fuel and run as well as you state.--It has over filled the crankcase a couple of times really fast and i changed it right away. I haven't been able to be behind my boat when it is running.

I run with clear 15 gallon fuel tanks and have filled up at the pump to make sure i have that much in there.
Motor only has 120 something hrs on it.
Shipping it to the dealer where i bought it cost me over $1000 round trip in freight and to get it back with it doing the somethings is a little disappointing.

Thanks for the help and being patient with me guys.
 
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