QSB 5,9 hunting with load

[Asbjoern Stoelen]

I recently bought a 2007 model cabincruiser with a QSB 5,9 425 hp.  550 running hours.  After running the first few hours I noticed the engine was sputtering a little bit. Could only feel it when the sea was flat.  The rpm was steady. I tried replacing the Racor filter but still the same issue. The filter on the engine was recently replaced. I called the previous owner and he said it was cavitation from the propeller, not sputtering. But he said it only occur around 2000 rpm’s. I had it from 1400- 2300 rpm’s.

After running the engine approx. 30 hours it got worse yesterday. I could only get 2500 rpm and 25 knots. (Normally I get 28 knots). I slowed down to 18 knots and the alarm sounded and “Check engine” in the display. No faulty codes were showing. After this the engine was hunting approx. 50 rpm’s on all loads except under 6 knots and on idling. I replaced the fuel filter on the engine and released the air as described by Tony on this forum. Tested again and still the same issue.

I noticed after the alarm that the fuel consumption on 18 knots was 58 liters pr. hour. Normally it is around 48-50 liters. Also the fuel tank was showing 99% for a while. (93% before the alarm)

Anyone have an idea what it can be? 

I’m from Norway by the way. (Sorry for my English…)

 

Topic

[Asbjoern Stoelen]

Looks like the issue was the Injection valve no.1. will replace it next week. 

Anyone knows what the Accelerator pedal or lever position sensor 1 fault means?

[Asbjoern Stoelen]

Thanks for replying 🙂

Engine serial number: 466908872

The alarm “check engine” comes around 1300 rpm. Engine also hunting a bit during idling. 600-610 rpm.

[Tony Athens]

First we have to sort out two things..

 

1——-I want to see the instruments you are looking at to monitor engine performance–Some clear pictures the the ignition on

 

2——–I want and engine serial number so I can look the performance curve & specs for your exact engine..

 

Start with that

[Author]

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