PCM 409 power loss

[LK_skier]

Hi all.

 

My PCM 409 with 550 hrs has started losing power whilst underway... it feels like it’s starved of fuel but then it comes good again for a bit then it’s bad etc. I’ve changed the fuel filters and added new plugs. It’s still there. Any ideas?? I’m hoping it’s not anything too horrible like a cracked head etc.

[oldjeep]

Have you checked/cleaned your air filter?

[Ali]

Oxygen sensors? You get a check engine light/code?

 

[skiinxs]

Put a fuel pressure gauge on the fuel rail and monitor fuel pressure when it loses power. That will give you the direction you need to go. If pressure drops when while the issue is occuring, look at fuel pumps, obstruction at fuel pickup in tank, anti-siphon valve, fuel tank vent obstruction, fuel hose deteriorated from alcohol in fuel, etc. If fuel pressure is constant, check for spark issues, wires, one of the coils, etc. Any check engine lights or indicators? If you don't want to buy one, you should be able to borrow a fuel pressue gauge from Autozone if there is one in your area. What year, does it have cats in the manifolds? If fuel pressure is not the issue, Diacom will give you a missfire count.

[kurtis500]

Since you've changed plugs, pull them out and do a compression test. That will indicate some bigger problems first, like a cracked head or etc.

[LK_skier]

Thanks all. Getting a diacom reading tomorrow ?? Will try the fuel pressure idea. Thanks

[Jody_Seal]

How old is your 409?

Things to consider.

Cracked or rotted hose in fcc pump.

Obstruction in the pick up tube of tank or antisyphon fitting.

Low pressure fuel pump screen clogged.

Bad grounds on engine or battery.

If its a older 196 and has had the steering cable replaced check the red wire coming from the battery to the breaker box ( pme).

Sometimes that wire when installing a cable can get damaged.

ECS working correctly.

Loose or poor performing key switch and or loose connection on touch pad.

Run a diacom screen. And have fuel pressure checked under load.

 

[bigtex2011]

@Jody_Seal AND @DW always seemed to have great motor info.

[LK_skier]

@Jody_Seal - thanks so much its a 2015 with 550hrs. Trying to get my hands on a fuel pressure monitor for the FCC. Good idea on the ignition - at one point it did feel like I had simply turned the engine off and back on again... Diacom - sometime this week... I just changed the fuel filter in the FCC and the screen looked clean as did the fuel hoses etc. Might go check the ignition now and re-check the FCC just to make sure.

 

[LK_skier]

Fixed. It was this little bugger stuck in the fuel tank pick up. The fuel pressure gauge proved it was fuel starvation, then my Malibu tech mate proved the fuel pumps were working so there had to be a blockage. Fuel tank out... fuel was clean... tried to blow down the intake pipe and it was restricted... poked a wire down and out popped this screw. It’s the one that use to hold the fuel filler lid to the chain stay...

 

[oldjeep]

Wow, what are the chances of that happening? Shouldn't there be a sock around the fuel pump, or does PCM still use a regular fuel filter?

[DW]

@LK_skier - I would check the fuel tank for the potential of a screen / plastic housing with screen / sock that might have dropped off at some point during ownership. You probably don't want to continue to draw any fuel tank debris up the inlet tube.

[skiinxs]

@LK_skier You are low on coolant. You should add before the reservoir is empty, it is sometimes hard to purge all of the air out of that system once it gets in, which can cause overheats

[LK_skier]

I inspected the tank as much as I could and it looks very clean... I doubt this Aussie built boat had a sock. Thanks all. I’ll check coolant level although it’s hard to check levels when the engine is angled and the reservoir doesn’t adjust for it.

[PatM]

2015? I noticed there are no Cats on that motor

[LK_skier]

@PatM Nope - good hey! My previous boat had the CATs and I found out the new owner had to put new risers in at a significant cost!! It was a 2015 built - perhaps an earlier engine? When did the CATs come into effect on these.

[oldjeep]

Looks like in au, no cats

https://cassellmarine.com.au/products/pcm-zr6-efi-409hp-centremount

[Rob]

@LK_Skier: thanks for sharing the solution to this - that helps everyone. I also happen to have a friend with a different engine but very similar symptoms so will be passing this on to him.

[LK_skier]

@Rob no worries - you really need a fuel pressure gauge on the FCC to diagnose it is a fuel issue and then go from there. the other thing that it could have been was a blocked fuel hose - they do get soft and can "kink" easily. When it drops try and listen for the pumps working or not (low pressure) - that will rule that out. My mate waited for the issue to hit us - then turn the boat off and used a multimeter to check if the high pressure pump was running an "open circuit" or not to rule that one out. Not that I really understand enough to describe it to anyone else. He said he also can use a stethoscope to listen to the pumps running. I initially thought it was a fuel pump and was close to ordering an expensive part - in the end no parts needed. He actually figured out it was the tank by blowing back into the (inlet hose) fuel tank and he could tell it was restricted that way.

[JayG80]

Rob, I had loss of power at acceleration and found a crack in the 2 inch long fuel line inside FCC canister.

[skiinxs]

Even the hoses that are supposed to be certified for 10% alchohol eventually deteriorate, swell, crack, etc. If you are running an older boat with hoses (and or tanks) that are not designed for the alcohol, you have a very dangerous situation. Inspect frequently, and preferably replace to be safe!