doublemint
New member
Hi guys,
I’m a bit lost with my engine, I tried to summarize all details as best as possible and hope some of you can help me out
The boat is a Chaparral 230 SSI
Engine:
Mercruiser 5.0 EFI Alpha One
Built in 2000, I think it says model year 1999 on the label leading to the diag-port
engine code is M031680
History & Symptoms:
I bought this boat last year and ran it for about 15 hours last year, without any problems, but noticed the oil plug was leaking. The dealer who sold me the boat asked me to bring it back and they allegedly removed the engine and replaced the oil drain hose and winterized the engine. After that the boat was sitting for about 5 months in a dry storage unit.
Put the boat back into the water 5 weeks ago and started the engine and it ran for about 2min before it went out, beeped and wouldn’t start again. I was towed into my box where the boat is sitting now.
I’ve had too many arguments with this dealer and they always charge a lot, so it’s no option to simply bring it back again
Heres what I did and observed:
- Removed flame arrestor, injectors were spraying (a lot of) fuel
- checked the cap and points, looks brand-new, no corrosion
- checked for spark, seemed a bit weak
- called a marine motor service, the guy was eager to help and suggested to replace the coil
- New Ignition coil was installed
- Fuel filter was replaced just to make sure
- There are about 200 liters / 53 gal of fresh fuel in the tank
- Still didn’t start most times and when it did, ran very rough
- checked an cleaned spark plugs, were a bit dark but did not seem very old
- there was fuel in 2 of 6 cylinders, 2 spark plugs were inaccessible due to cooling hoses blocking the way
- after cranking the engine without plugs and removing excessive fuel and reinstalling everything the engine would start but still run rough
- service guy brought his laptop and diacom cable
- There was an error code: „Manifold Air Pressure Sensor Voltage High“
- Also Spark Advance was jumping between 2 and 14 DEG very rapidly, I read it should be 16 DEG on idle
- Installed a new MAP Sensor
- Also found the knock sensor cable seemed loose, new connector was installed, cleaned the sensor’s pin for proper connection [Note: Knock sensor seems rusty and wasn’t replaced. Service guy said it rarely fails and was challenging to remove due to the rust]
- Engine would start perfectly 5-6 times and run smoothly, would rev over 3,500 rpm in neutral. I thought the problem was solved [Note: Spark Advance was still jumping between 2 and 14 DEG rapidly]
Did a test run, noticed the engine startet to run rough again and did not go over about 1,800 rpm, sounded like it was getting way to much fuel and was about to stall again. Made it back to the marina and switched off, then waited a few minutes, could restart one more time (engine was running very rough) and was not able to start the engine again since that day.
- I cleaned and polished all grounds for good connection and checked all connectors I could find, they all seem OK
- thought it might be the ignition sensor and replaced that as well
Situation is still the same: Engine cranks over but won’t start. It always sound’s like it’s about to fire but as soon as I let the starter go, the engine stops. Removed the air arrestor again and noticed both injectors are spraying what I feel is a normal amount of fuel (and not way too much as it was in the beginning).
I’m really lost and have no idea where to go from here...
Any idea is much appreciated!
I’m a bit lost with my engine, I tried to summarize all details as best as possible and hope some of you can help me out
The boat is a Chaparral 230 SSI
Engine:
Mercruiser 5.0 EFI Alpha One
Built in 2000, I think it says model year 1999 on the label leading to the diag-port
engine code is M031680
History & Symptoms:
I bought this boat last year and ran it for about 15 hours last year, without any problems, but noticed the oil plug was leaking. The dealer who sold me the boat asked me to bring it back and they allegedly removed the engine and replaced the oil drain hose and winterized the engine. After that the boat was sitting for about 5 months in a dry storage unit.
Put the boat back into the water 5 weeks ago and started the engine and it ran for about 2min before it went out, beeped and wouldn’t start again. I was towed into my box where the boat is sitting now.
I’ve had too many arguments with this dealer and they always charge a lot, so it’s no option to simply bring it back again
Heres what I did and observed:
- Removed flame arrestor, injectors were spraying (a lot of) fuel
- checked the cap and points, looks brand-new, no corrosion
- checked for spark, seemed a bit weak
- called a marine motor service, the guy was eager to help and suggested to replace the coil
- New Ignition coil was installed
- Fuel filter was replaced just to make sure
- There are about 200 liters / 53 gal of fresh fuel in the tank
- Still didn’t start most times and when it did, ran very rough
- checked an cleaned spark plugs, were a bit dark but did not seem very old
- there was fuel in 2 of 6 cylinders, 2 spark plugs were inaccessible due to cooling hoses blocking the way
- after cranking the engine without plugs and removing excessive fuel and reinstalling everything the engine would start but still run rough
- service guy brought his laptop and diacom cable
- There was an error code: „Manifold Air Pressure Sensor Voltage High“
- Also Spark Advance was jumping between 2 and 14 DEG very rapidly, I read it should be 16 DEG on idle
- Installed a new MAP Sensor
- Also found the knock sensor cable seemed loose, new connector was installed, cleaned the sensor’s pin for proper connection [Note: Knock sensor seems rusty and wasn’t replaced. Service guy said it rarely fails and was challenging to remove due to the rust]
- Engine would start perfectly 5-6 times and run smoothly, would rev over 3,500 rpm in neutral. I thought the problem was solved [Note: Spark Advance was still jumping between 2 and 14 DEG rapidly]
Did a test run, noticed the engine startet to run rough again and did not go over about 1,800 rpm, sounded like it was getting way to much fuel and was about to stall again. Made it back to the marina and switched off, then waited a few minutes, could restart one more time (engine was running very rough) and was not able to start the engine again since that day.
- I cleaned and polished all grounds for good connection and checked all connectors I could find, they all seem OK
- thought it might be the ignition sensor and replaced that as well
Situation is still the same: Engine cranks over but won’t start. It always sound’s like it’s about to fire but as soon as I let the starter go, the engine stops. Removed the air arrestor again and noticed both injectors are spraying what I feel is a normal amount of fuel (and not way too much as it was in the beginning).
I’m really lost and have no idea where to go from here...
Any idea is much appreciated!
