Hi all,
I recently purchased a Yamaha HPDI 200 for my 19’ center console. The motor has 100+ compression and is within 10% range in all cylinders. After purchase I installed new spark plugs, new racor filter, and new fuel filter (the one before the LP pumps). It ran great for a few trips and then began developing the following problems:
1. On a choppy day and with a lot of weight, it began to surge at higher RPMS and the rpm’s would fluctuate slightly. I then took the boat out with less weight and it still had the same issue but not quite as bad. I did a lot of research and reading from this point forward.
2. Before taking it out again I purchased the YDS software. With the ignition on and engine off, all of the readings looked to be within range. I had a replacement VST filter and gasket so I changed those and then took the boat out for a test. All of the numbers and data on the YDS still looked to be normal. However, the engine would not get above 1700-1800 rpm. If I left the throttle all the way down it would eventually start to climb slowly and get on plane. I was hesitant to put it above 3200rpm.
3. I then did a throttle synchronization and TPS adjustment and checked the spark plugs. The motor now wouldn’t hold idle. It would die out after 5-10 seconds. I changed the low pressure pumps, high pressure pump mystery filters, and 3 fuel injector filters. I also cleaned the oxygen sensor. Now the motor would idle fine but still would not get above 1700-1800rpm.
I plan on changing the medium pressure filter (the metal canister) and remaining 3 fuel injector filters but I’m not optimistic these will solve the problem. The VST and High pressure pump psi’s are within the range of the manual. All 6 cylinders are firing according to YDS. Shift position switch is working as it should according to YDS. What are the chances that plugging in the YDS shorted or messed up something with the ECU? That seems to be when the 1700rpm problem started. Oil tank and sensor seems to be working appropriately. No alarms or codes on YDS.
When I initially plugged the YDS in, I noticed that the engine hours was only 68. The guy I bought the motor from had a pair (the other one had low compression which is why he was selling them). He was very helpful and I’m sure he would give me whatever parts I needed from the other motor. I find it odd that an 18 year old motor has 68 hours so the ECU might have been replaced at some point, I’m not sure. But it was running fine for the first week or two I had it and would get on plane with no problem or symptoms.
I have read of a somewhat similar problem caused by the exhaust tuner, however it seems to be few and far between. I have not checked it because I keep the boat in the water and do not have a trailer at the moment. Is there a way to get a better idea if it may be the culprit before I go hunting down a trailer?
I have not checked the voltage output of the fuel pressure sensor because my fuel sensor readings seem to be okay and I do not have a test harness. Is there another way to test the fuel pressure sensor? I have checked the fuel pressure regulator and that was within spec.
Any help would be greatly appreciated!!
I recently purchased a Yamaha HPDI 200 for my 19’ center console. The motor has 100+ compression and is within 10% range in all cylinders. After purchase I installed new spark plugs, new racor filter, and new fuel filter (the one before the LP pumps). It ran great for a few trips and then began developing the following problems:
1. On a choppy day and with a lot of weight, it began to surge at higher RPMS and the rpm’s would fluctuate slightly. I then took the boat out with less weight and it still had the same issue but not quite as bad. I did a lot of research and reading from this point forward.
2. Before taking it out again I purchased the YDS software. With the ignition on and engine off, all of the readings looked to be within range. I had a replacement VST filter and gasket so I changed those and then took the boat out for a test. All of the numbers and data on the YDS still looked to be normal. However, the engine would not get above 1700-1800 rpm. If I left the throttle all the way down it would eventually start to climb slowly and get on plane. I was hesitant to put it above 3200rpm.
3. I then did a throttle synchronization and TPS adjustment and checked the spark plugs. The motor now wouldn’t hold idle. It would die out after 5-10 seconds. I changed the low pressure pumps, high pressure pump mystery filters, and 3 fuel injector filters. I also cleaned the oxygen sensor. Now the motor would idle fine but still would not get above 1700-1800rpm.
I plan on changing the medium pressure filter (the metal canister) and remaining 3 fuel injector filters but I’m not optimistic these will solve the problem. The VST and High pressure pump psi’s are within the range of the manual. All 6 cylinders are firing according to YDS. Shift position switch is working as it should according to YDS. What are the chances that plugging in the YDS shorted or messed up something with the ECU? That seems to be when the 1700rpm problem started. Oil tank and sensor seems to be working appropriately. No alarms or codes on YDS.
When I initially plugged the YDS in, I noticed that the engine hours was only 68. The guy I bought the motor from had a pair (the other one had low compression which is why he was selling them). He was very helpful and I’m sure he would give me whatever parts I needed from the other motor. I find it odd that an 18 year old motor has 68 hours so the ECU might have been replaced at some point, I’m not sure. But it was running fine for the first week or two I had it and would get on plane with no problem or symptoms.
I have read of a somewhat similar problem caused by the exhaust tuner, however it seems to be few and far between. I have not checked it because I keep the boat in the water and do not have a trailer at the moment. Is there a way to get a better idea if it may be the culprit before I go hunting down a trailer?
I have not checked the voltage output of the fuel pressure sensor because my fuel sensor readings seem to be okay and I do not have a test harness. Is there another way to test the fuel pressure sensor? I have checked the fuel pressure regulator and that was within spec.
Any help would be greatly appreciated!!