Loss of power & backfire

[lussierd16]

I'm having a similar issue with my 2001 Sunsetter VLX. Just started happening 2 weeks ago. It idles ok and anything over 2700 RPM it starts to gurgle and backfire once in a while. I replaced the low pressure fuel filter by the tank earlier this season and replaced the high pressure fuel filter yesterday. Still having the issues. I was told to replace the water separator filter but I don't see a water separator anywhere. The manual seems to have one in the diagram but I can't find it. Can someone point me in the right direction or is that something that may not be installed for this model/year?

Thanks!

[justgary]

17 hours ago, braindamage said:

The fuel lines are high pressure and have press-on fittings. Is this something I can order or will I have to find someone to custom make them?

Your local auto parts store may sell marine fuel line and have the ability to swage fittings for you. 

BTW, I'm talking about the lines from the tank and back.  My '99 just has barbs and clamps.  I'm surprised yours doesn't....

[justgary]

6 minutes ago, lussierd16 said:

I'm having a similar issue with my 2001 Sunsetter VLX. Just started happening 2 weeks ago. It idles ok and anything over 2700 RPM it starts to gurgle and backfire once in a while. I replaced the low pressure fuel filter by the tank earlier this season and replaced the high pressure fuel filter yesterday. Still having the issues. I was told to replace the water separator filter but I don't see a water separator anywhere. The manual seems to have one in the diagram but I can't find it. Can someone point me in the right direction or is that something that may not be installed for this model/year?

Thanks!

You may not have one.  Have you tested your fuel pressure at idle and WOT?

[lussierd16]

1 hour ago, justgary said:

You may not have one.  Have you tested your fuel pressure at idle and WOT?

No. where do you connect the fuel pressure guage to?

[BlindSquirrel]

9 minutes ago, lussierd16 said:

No. where do you connect the fuel pressure guage to?

There is a barb on the fuel rail. Take the flame arrester off, then the carbon fiber cover to reveal the fuel rail. It’s on the side of your engine facing the rear. Under a black cap, you can’t miss it.

[BlindSquirrel]

While you’re there you might pop out your fuel injectors and have a look. They could be clogged too.

[braindamage]

I flew back on a red eye this am and had about 30 mins between work calls to do the fuel pressure test.

I have pressure that is within spec at key turn and idle, but it hasn’t died yet.  The pressure at 5000 rpm is a bit lower than spec: 40 vs 43-45 but it seems fine. There is a bit of hesitation (bog) that happens intermittently, but am not sure this is relevant to this issue.

im goin to keep it at idle for a while until it dies. I’ve never before wished that my boat would die before. 🤷‍♂️

[braindamage]

I continue to idle while in the hoist. Super frustrating that I’ve been idling for about 30 mins and no problems.

i have been reving the engine, and I notice a “bog” that happens between 2300-2500 rpm consistently. Not enough to stall, but enough to notice.

[Eagleboy99]

Throw a can of SeaFoam in.  

[braindamage]

I replaced the ICM easy, relatively cheap. Pulled the disty and this is what I see. Wow. Corroded!!

off to replace that now

[Eagleboy99]

Wow is right.  I know it is hard (and spendy) to play "Parts Whackamole", but sometimes the basics are the place to start.  Hope it works now!  BTW, I did mine last year and it looked nothing as bad as that!

[BlindSquirrel]

5 minutes ago, braindamage said:

I replaced the ICM easy, relatively cheap. Pulled the disty and this is what I see. Wow. Corroded!!

off to replace that now

I just bought one for my tug. Here is the least expensive one I found. 

https://www.ebay.com/itm/NIB-Indmar-V8-5-0-5-7-7-4-8-2Delco-EST-Ignition-Distributor-Cap-Rotor-808483Q-1/292938580241?epid=27006846969&hash=item4434800111:g:zPMAAOSw-QxcUE2z

[braindamage]

New ICM, disty cap, and rotor. Idled back/forth from my best ski buddy’s place no problem. I’ll take it out this am again to test

update: runs like a champ. Hole shot has improved! I’ll inspect the plugs today.

thanks to all for your help!

Edited August 17, 2019 by braindamage

[lussierd16]

So I'm having the same issues. Today I tested fuel pressure. It was 41 PSI at keyup and 33 PSI at idle. It held at 33 all the way to 5200 RPM. The Indmar engine manual says for the 5.7L TBI it should be 30 PSI at keyup and the 5.7L MPI  engine should be 40 PSI at keyup. Does that mean I have the MPI? Not sure how to tell.

The problem is I can't reproduce the bogging in my driveway with fake lake. 

Last weekend I also experienced the "bog" at 2500-2700 RPM on the water.

Any thoughts?

https://photos.app.goo.gl/ZXAkH8i91bnTmbdz8

[Sixball]

So I have not dealt with this on my Bu. But I did see something  like this working on an outboard.  I don't know if the ECU knows you are in neutral and no load but the issue I was working on went away in neutral but as soon as I put it back in the water in gear my miss came back. I would think the ECU knows the gear selection and has different base strategy over a pull under load. It will start looking at TP, ECT, load, and probably other things in gear.     

[NHolladay]

On 8/10/2019 at 6:01 AM, braindamage said:

There’s a new whine from the fuel pump when initially turning on the key, so I think that’s my culprit.

bummer...glassy glass this morning, my MC ski buddy is out of town and my boat is dead

Change the filter first. The wine is from sucking harder not because the pump is bad.  

[lussierd16]

I replaced both fuel filters early on. Pressurised and non pressurised. It didn't seem to help my case. 

My distributor cap was corodded some.

Before cleaning:

https://photos.app.goo.gl/xPF9RvDeLWtpeWpdA

Should I just replace it? I scrubbed everything with fine wire brush to remove corrosion so it seems a lot better.

 I noticed my center spark plug wire was very corodded. I think I'll need to replace those cables. Does anyone know part number for those?

I have new spark plugs. I just need to get a tool to gap them properly then I'll put them in.

[justgary]

5 hours ago, lussierd16 said:

So I'm having the same issues. Today I tested fuel pressure. It was 41 PSI at keyup and 33 PSI at idle. It held at 33 all the way to 5200 RPM. The Indmar engine manual says for the 5.7L TBI it should be 30 PSI at keyup and the 5.7L MPI  engine should be 40 PSI at keyup. Does that mean I have the MPI? Not sure how to tell.

The problem is I can't reproduce the bogging in my driveway with fake lake. 

Last weekend I also experienced the "bog" at 2500-2700 RPM on the water.

Any thoughts?

https://photos.app.goo.gl/ZXAkH8i91bnTmbdz8

I was hoping your photo was your engine so we could tell you if you have MPI or TBI.  With a 2001, I'd bet it's MPI. 

If you have a fuel rail that goes up one side of the intake manifold, then bridges over to the other side and down again, and each side has four devices with two wires each stuck into the intake manifold, then it's MPI....

[Eagleboy99]

10 minutes ago, justgary said:

if you have MPI or TBI.  With a 2001, I'd bet it's MPI.

Short answer is the Monsoon is Port Fuel Injected.

[justgary]

13 minutes ago, Eagleboy99 said:

Short answer is the Monsoon is Port Fuel Injected.

I was trying to make him work for it just a little bit! 

[lussierd16]

Ok so I replaced all the spark plugs with new and reconnected distributor cap and cables. It started right up. Everything seemed fine. Good fuel pressure and numbers seemed fine but I heard a clicking and found the center spark plug cable that goes to the ignition coil is arcing on the ignition coil side. I can't win 😖

I think that cable is bad maybe? Thoughts?

 

Engine pic. Can't really see the fuel rails in this one but I've already covered it up for the night.

https://photos.app.goo.gl/daqAC8UEbAzpuQdZ9

Next step was thinking to replace that spark plug cord to ignition coil then try it out in the lake.

 

[justgary]

7 minutes ago, lussierd16 said:

Ok so I replaced all the spark plugs with new and reconnected distributor cap and cables. It started right up. Everything seemed fine. Good fuel pressure and numbers seemed fine but I heard a clicking and found the center spark plug cable that goes to the ignition coil is arcing on the ignition coil side. I can't win 😖

I think that cable is bad maybe? Thoughts?

 

Engine pic. Can't really see the fuel rails in this one but I've already covered it up for the night.

https://photos.app.goo.gl/daqAC8UEbAzpuQdZ9

Next step was thinking to replace that spark plug cord to ignition coil then try it out in the lake.

 

Good photo.  You can see the fuel rails peeking out of each side of the plastic cover. 

You can also see the original 2001 Indmar spark plug wires.  So yes, it's time for new wires, and not just the one for the coil....

[Eagleboy99]

14 minutes ago, justgary said:

it's time for new wires

Is it?  Mine in the 99 are fine.  I mean it can't hurt, but as long as it runs...

[justgary]

1 hour ago, Eagleboy99 said:

Is it?  Mine in the 99 are fine.  I mean it can't hurt, but as long as it runs...

I guess when you post here that your engine bogs down and you can see the arcing because the coil wire is failing, I'll tell you it's time for new wires. 

I changed my wires (along with the usual suspects) in my '99 when I bought it five years ago.  I also changed the fuel and exhaust hoses, but it's only because I have learned that preventive maintenance seems to have a way of keeping bad luck away. 

[mswsetter00]

If you find out you need a new fuel pump I do NOT recommend that kit from Bakes. I just did used it this year. The bracket leaked fuel and I had to go buy 1/2" fuel hose from dealer and find a hose Barb to adapt 3/8"-1/2". I also had to cut both wire plugs off and splice in connectors. $400.00 kit from Indmar and it sucks. Use this instead, found a good article about someone who installed it.

www.summitracing.com/parts/crt-p61171

I still have fuel issues is why I'm reading post and following. I have a stumble now on take off and, not every time.  It has done it while on plane. It's as if someone pinched the fuel off for a second and then started again. Exhaust smells really rich at idle. 

2000 Wakesetter VLX 5.7L MPI 1198hrs.

Replaced: Cap, rotar, spark plugs, coil/ignighter, ignition module, intake air temp sensor, map sensor, TPS, fuel filters, fuel pump, fuel pressure regulator fuel injectors, and thermostat even removed throttle body and cleaned it. Maybe idle air control valve, but broke a torqx bit off in screw head because GM used lock tite on a 4mm screw.😡

Thinking of advancing timing or taking to a dealer. This has been going on for awhile.