1996 Penta 5.0Fi and SX COBRA

[rbwhiz]

Ok guys and gals. I looked around and couldn't find the issue I'm having. But hopefully I can find some help here. I can put the ear muffs on at the house and runs smooth including in gear.... Everything is great. I take it too the lake, put it in, put it in gear.... Dies... Have to rev her up immediately in gear to get it to go. Will run for about a minute or two.... Bogs down and dies..... A little hard to start back up from choking down. Limp it back in.

Have changed all fluids, including gas and running seafoam. Before the previous owner had put too much oil in the outdrive. Thought that was the issue because it would die once I put it in gear, even at the house and quit and I got it to the correct level. Anyhow .....

..... I'm stumped other than maybe rebuilding the lower unit. . Hoping and praying y'all have some advice out here.

Thank you

 

[alldodge]

Welcome
Don't see it as a drive issue

Is this a new to you boat?

I'll assume you don't have a scanner, so I would start with the basics
Do a compression test (TB at WOT and crank over at least 4 times, more is better)

Check fuel pressure at the rail (should be 50 to 60psi)

 

[rbwhiz]

It is pretty new to me. 1996 Chris Craft concept 21. Has good compression, etc. I've had it running long enough and gets up to 40+ quickly when i can get it going.

 

[rbwhiz]

Welcome
Don't see it as a drive issue

Is this a new to you boat?

I'll assume you don't have a scanner, so I would start with the basics
Do a compression test (TB at WOT and crank over at least 4 times, more is better)

Check fuel pressure at the rail (should be 50 to 60psi)

I'll try and check that fuel pressure tho.

 

[Scott Danforth]

Post the compression numbers
Post the fuel pressure numbers

 

[cwella]

Ok guys and gals. I looked around and couldn't find the issue I'm having. But hopefully I can find some help here. I can put the ear muffs on at the house and runs smooth including in gear.... Everything is great. I take it too the lake, put it in, put it in gear.... Dies... Have to rev her up immediately in gear to get it to go. Will run for about a minute or two.... Bogs down and dies..... A little hard to start back up from choking down. Limp it back in.

Have changed all fluids, including gas and running seafoam. Before the previous owner had put too much oil in the outdrive. Thought that was the issue because it would die once I put it in gear, even at the house and quit and I got it to the correct level. Anyhow .....

..... I'm stumped other than maybe rebuilding the lower unit. . Hoping and praying y'all have some advice out here.

Thank you

Running fine on muffs but dying under load usually points to a fuel or ignition issue, not the lower unit.

Check:
• Fuel filter, fuel pump, anti-siphon valve, and carb main jets
• Try adding choke when it bogs; if it improves, it’s likely starving for fuel
• Verify idle speed and mixture in gear
• Check plugs, coils, and timing for issues that appear under load

Don’t rebuild the lower unit yet unless you have grinding, noise, or excessive drag. What engine/year is it?

 

[Scott Danforth]

. What engine/year is it?

Read the title of the thread

 

[rbwhiz]

Found the problem. The filter was powder white gas (ethinol).... Changed it... As well as a better fuel line. But put a pressure test on it.... 32 lbs is the best and takes a minute to get there. Where would y'all go from here? I'm not sure this one has the fuel screen??? I know Volvo suggested to pull these. Or do you think go straight to the fuel pump?

 

[rbwhiz]

And I found out this is NOT a GXI. it's a 5.0 Fi. Sooo.. that's been a problem on my end for looking things up

 

[alldodge]

Your not answering any questions asked so good luck, hope you can figure it out

 

[rbwhiz]

Your not answering any questions asked so good luck, hope you can figure it out

I've answered several. Doing that as I'm finding them out. I just answered your question about the fuel pressure. I haven't checked compression yet . And I answered your question to if it's new to me. Why are you saying that I haven't?

 

[alldodge]

Apologies, don't know why I didn't see fuel pressure, still looking for compression

Being a Fi so it's a Ford and your fuel pressure is ok, list between 31-39 psi

Changed title to Fi

 

[Lou C]

running in the water is different because of the under water exhaust back pressure, wonder if you have either restrictions (anti siphon valve, pick up tube) or an air leak. can you do a fuel pump volume test?

 

[rbwhiz]

running in the water is different because of the under water exhaust back pressure, wonder if you have either restrictions (anti siphon valve, pick up tube) or an air leak. can you do a fuel pump volume test?

Not exactly sure how. But I'm wondering about this. Because it took like 30 seconds to build up to 32 lbs..... Was def not immediate. And this was while running.

 

[rbwhiz]

Apologies, don't know why I didn't see fuel pressure, still looking for compression

Being a Fi so it's a Ford and your fuel pressure is ok, list between 31-39 psi

Changed title to Fi

Thank you. I'll be checking that this week.

 

[Lou C]

With fuel pumps, pressure, volume and vacuum are all important.
pressure and volume are obvious, but vacuum will tell you if your anti siphon valve is stuck/clogged or if there is a screen on the end of the fuel tank pick up tube that is blocked by crud. Using a clear fuel line between the fuel line from the tank and the pump will show you if air is being drawn in, this can happen from pinholes in the fuel line, or in the pick-up tube itself.

 

[rbwhiz]

Well this has been what my next step is. That's with a clear line going straight into a gas can. But how's the dang thing running? Lol. Maybe The low pressure pump out and the high is trying to suck it up? I remember when I ran my high pressure test, it was not immediate. It took it like 45 seconds or so to get up to 32 lbs. Unless y'all tell me something different, I'm thinking to replace the fuel pumps.

 

[Lou C]

Well it’s hard to say from looking at the clear line but the engine seems to be hunting/surging. If it doesn’t run any better when run on a seperate fuel tank that suggests that the issue isn’t your fuel tank pick up tube or anti siphon valve. I have never had a boat with EFI so I don’t know if the pressure should jump up right away or build up gradually. Im
Guessing it should be immediate though. I tested mine for vacuum (how well does the pump suck with the engine at cranking speed) and the pump immediately exceeded the spec for mechanical pumps at 13” Hg. Spec is 9-10” Hg. Im
Going to do a pressure test next so I’ll see how it behaves (but mechanical pumps are only supposed to put out about 5 psi).

So it ran exactly the same on the seperate tank as it did on the main tank, is that right? Because when you mentioned powdery deposits in the fuel filter I thought it might be wise to check and inspect the anti siphon valve and pick up tube just to leave no stones unturned. I wonder if the fuel pumps have screens that could be clogged with the same powdery stuff. Got a shop manual for that EFI system?