2000 islandia loss of power 240 efi

[Bigal2368]

Hi guys, sorry my phone got all messed up and I had to create a new acct. My 2000 islandia has had some issues. In short I replaced head gaskets. Ran great better than ever. After a 2 hr ride a sudden loss of power, I have 36 psi fuel pressure, replaced all fuel filters , even cleaned vst . 125 psi compression on all 6 holes. Replaced temp sensor and pulled out of water to check for debris in the inlet grate. WHAT THE HELL AM I MISSING????
Just to be clear, after head gaskets were replaced I could go 40 mph at 3/4throttle with 6 people aboard. Now I can do 18mph with 2 people full throttle. Starts right up and idles perfect

.

 

[rsatina2002]

Is your impeller and wear ring clearance ok? Check your impeller condition maybe it causes bad cavitation and wear ring? post some pictures... we might have some good idea whats wrong or maybe your fuel injector needs to be reconditioned/cleaned.

 

[Tim75]

What rpm do you get at wot?

 

[Bigal2368]

The tech reads 5000 , but it's off. I dont think it's a wear ring or cavitation issue, it does not rev hi at all. My guess would be 3000 If I put it in reverse and open the throttle I can hear it cavitate and rev up like it should. Again we were crusing fine and all the sudden lost power .

 

[Tim75]

The tach is a critical diagnosis tool, and it must be correct & reliable. That is issue number 1.
Not high revving??? 5000 rpm IS high revving; but is it? We need to know for sure.

Overall, it sounds like the leading edges of the impeller are damaged. It only would take a split second if you sucked up a rock. Look up into the pump intake. You can see the leading edges.

 

[Bigal2368]

The tach is a critical diagnosis tool, and it must be correct & reliable. That is issue number 1.
Not high revving??? 5000 rpm IS high revving; but is it? We need to know for sure.

Overall, it sounds like the leading edges of the impeller are damaged. It only would take a split second if you sucked up a rock. Look up into the pump intake. You can see the leading edges.

I will look this weekend. It is at our lake house a hour from where I live. We were in 15 feet of water going at 35 mph when the power loss occurred. Not sure a rock could get in there . I could hear the engine losing power , almost as if I was throttling back. And really that's how it feels now , like I'm at half throttle ?
Just a lil background about myself, I'm a ase certified auto technician for 26 years . And I am new to boats .

 

[Bigal2368]

I hear what your saying , I had a jet ski with a bad wear ring,(friends sucked up the tubing robe around the driveshaft ) and I know how that sounds , engine revs hi without any propulsion. The boat is different from how that was

 

[Gr8laker]

Could be a bad coil pack. We were boating in AR, got up on plane and power began to cut out. I throttled down, and could not get back on plane. Could only go 10 mph. Explained to the Marina mechanic what happened, he diagnosed that it was one of the coils. He didn't have the one I needed, but found one later online for $40.

 

[Tim75]

Have you checked your tach yet? On the engine, you have 2 voltage regs. Both have a tach signal output. It's the gray wire. You can try swapping the tach wire to the other reg.

When you checked the compression, was it right after the head o-rings were replaced, or after the power loss? All kinds of mech. things COULD have happened, but it sounds more like electrical. Check the trigger base with ohm meter. Easy access. Open the connector, aft of flywheel, on top of a small bracket.

Have you had a chance to look at your impeller leading edges yet?

Fuel injectors- I had mine done a year ago. Big difference. Remember- they are 20 years old. I get better performance on less gas.

 

[Bigal2368]

Hey guys current update. Worked on the boat this past weekend and started from scratch. 1. Compression. Top 4 cylinders are solid 125psi. Bottom 2 are 105 and 110psi.
2. Had 3 spark testers soo we did a bank at a time . Both middle cylinders some times seen to go out for a second at idle, but under a slight load , light stays strong and solid
. I forgot to inspect wear ring and propeller. But the compression worries me .

 

[Tim75]

Yes, those low numbers are of concern. Even the 125 cyl's. Spec is 135-140. Was compression checked at WOT? It should be, to get the best numbers. At this point, you might get by with a "refresh rebuild". New rings and a light honing.
Assuming there is no actual cylinder damage.

Intermittent spark- check wiring. Start at kill switch and work to the engine. The black wire w/ yellow stripe is the kill wire. Check connector to each coil. Do you have the throttle guardian?

 

[Bigal2368]

No I dont think I do have the throttle guardian. I did not check compression at wot. It was actually closed throttle. I saw rebuild kits are around 1200.00 is that right?

 

[Tim75]

No I dont think I do have the throttle guardian. I did not check compression at wot. It was actually closed throttle. I saw rebuild kits are around 1200.00 is that right?

$1200 sounds high. 6 ring sets and a gasket set. Injector service for fun. Estimate about $600.

 

[Bigal2368]

I was told this was a rebuilt engine 2 years before I bought it. It appears clean so hopefully rings will work. Do I need to pull the engi e out to do it? Or can it be done in the boat?
The guy I got it from was very paranoid about running it out of the water with the hose connected, is there any issues I'n doing that?

 

[Tim75]

2 or 3 minutes on the hose should be OK. Use a large hose, as short as will reach, no "quick connects" or other restrictions. You should get water out of the pee hole. If none, check for bug nest in the hose from the cylinder head. Nests can block the water 100%. If hot water can't get out, cool water can't get in. It can cost you a piston meltdown.

If engine actually was rebuilt, you should have better compression. Check it again at WOT, all plugs out.

Have you checked that throttle plates are in fact opening 100%? It works like an old 4-barrel carb. 2 open first, then the other 2.

 

[dblackstone]

Yes, check compression again, double check you have the gauge on good especially the bottom 2 cylinders as they are harder to reach. WOT plugs out.

 

[Bigal2368]

I think were leaning on trading it in. That is for all you advise

 

[Bigal2368]

Ok soo. I really wanna figure this out. Starts idles perfect. If I throttle up , I can get it to 12 mph . Rpms dont go above 5000. If I back down the throttle to half , speed and rpm stay the same . I will gladly tear it down and put rings in it , if you think that will fix it.

 

[Tim75]

Don't do anything until you properly check the compression and get a reliable tach.

The is very little that can be done to the engine (in the way of overhaul) in the boat. Gotta pull it.