Hi Everyone. I am in desperate need for ideas on why my 2002 HDPI 200 z motor is sick.
I think it is important to give a quick backstory on what I have done so far.
When I got the boat it was a year before I could actually put it in the water.
I started preempted maintenance last year. I found a completely dead injector , replaced and replaced all injector basket filters..
replaced spark plugs, cleaned o2 sensor. replaced VST filter. ran seafoam through.
I noticed the little white collar at the top of the vst pump was missing, replaced that and o ring.
I wonder if someone left it out on purpose....more on that later. The gasket that goes between the top and bottom of the VST was also leaking, replaced that.
Replace the tank vent and fuel fill hose, and replace the sending unit because it was letting in water into the tank. Changed out the fuel water separator.
Cpmpression was 105/110 each cylinder cold.
The motor has always ran a touch rich, and never has a smooth idle or ideal sound at any rpm.
When we first took it out, it ran fairly good at any rpm under about 2500. It has a strong 2 stroke smell, but it ran. Gets on plane fast, and it will fall off after about 30 seconds, and then stalls out. You can restart immediately and repeat the process.
So after that day I took apart the VST and realized that the aftermarket VST filters sit offset, and cause the fuel pump to tilt a bit when closing the vst up. Lesson learned, replaced with OEM.
Replaced BOTH low pressure pumps (OEM) because one was leaking from the back. Changed the filter in the under cowl water separator, switched out the anti siphon valve on the tank for a straight through barb, at least for a while to test. Changed the fuel hose to the tank.
Inspected the spark plugs, looked OK except for the bottom two that had carbon build up.
Hooked up to YDS and verified no codes, low pressure was at 4.8psi and high pressure was bouncing from 675 to 720. Ran the rpms up to 2800 and everything seemed stable until about 30 seconds when fuel pressure starting dropping on both the low side and high side and it shut off. I couldn't tell which pressure dropped first.
I changed the mystery filter in the HP pump. put everything back together. Engine wouldn't stay running, and was backfiring and popping. Looked at the spark plugs and they were all black and dry, like charcoal. Cleaned them, engine ran "ok" until I tried the test again, back to black sooty plugs.
The only thing I haven't done is verify the pressure coming from the VST because I don't have an adapter, but I HAVE tried two different electric pumps. I also couldn't get the fuel pressure regulator off the top of the VST to inspect without the screws rounding out.
So I am running out of funds and patience, and I really want to get this thing running decently. It only has 409 hours on it, and I think I am logically tracing the issues.
Why would a motor blacken the plugs in 2 or 3 min of running? too much fuel or oil? I adjusted the oil rod. Seems to me too much oil wouldn't cause the cutting out issue, unless it was ridiculous amount of course.
Just before the engine cuts out at 2800rpm it momentarily increases rpm on it's own, probably the ecu's last resort before cutting off from a lean condition? I think they call that flaring?
I would bite the bullet and purchase anything if I was SURE it was the issue, but chasing parts is breaking the bank.
I suspected the HP pump is failing, but wouldn't that show lower pressure at all times?
If the HP pump was running out of fuel from the VST, why would I have to clean the black off my plugs so quickly? Unless, the ECU is dumping oil to correct???
Any help here is GREATLY appreciated.
I think it is important to give a quick backstory on what I have done so far.
When I got the boat it was a year before I could actually put it in the water.
I started preempted maintenance last year. I found a completely dead injector , replaced and replaced all injector basket filters..
replaced spark plugs, cleaned o2 sensor. replaced VST filter. ran seafoam through.
I noticed the little white collar at the top of the vst pump was missing, replaced that and o ring.
I wonder if someone left it out on purpose....more on that later. The gasket that goes between the top and bottom of the VST was also leaking, replaced that.
Replace the tank vent and fuel fill hose, and replace the sending unit because it was letting in water into the tank. Changed out the fuel water separator.
Cpmpression was 105/110 each cylinder cold.
The motor has always ran a touch rich, and never has a smooth idle or ideal sound at any rpm.
When we first took it out, it ran fairly good at any rpm under about 2500. It has a strong 2 stroke smell, but it ran. Gets on plane fast, and it will fall off after about 30 seconds, and then stalls out. You can restart immediately and repeat the process.
So after that day I took apart the VST and realized that the aftermarket VST filters sit offset, and cause the fuel pump to tilt a bit when closing the vst up. Lesson learned, replaced with OEM.
Replaced BOTH low pressure pumps (OEM) because one was leaking from the back. Changed the filter in the under cowl water separator, switched out the anti siphon valve on the tank for a straight through barb, at least for a while to test. Changed the fuel hose to the tank.
Inspected the spark plugs, looked OK except for the bottom two that had carbon build up.
Hooked up to YDS and verified no codes, low pressure was at 4.8psi and high pressure was bouncing from 675 to 720. Ran the rpms up to 2800 and everything seemed stable until about 30 seconds when fuel pressure starting dropping on both the low side and high side and it shut off. I couldn't tell which pressure dropped first.
I changed the mystery filter in the HP pump. put everything back together. Engine wouldn't stay running, and was backfiring and popping. Looked at the spark plugs and they were all black and dry, like charcoal. Cleaned them, engine ran "ok" until I tried the test again, back to black sooty plugs.
The only thing I haven't done is verify the pressure coming from the VST because I don't have an adapter, but I HAVE tried two different electric pumps. I also couldn't get the fuel pressure regulator off the top of the VST to inspect without the screws rounding out.
So I am running out of funds and patience, and I really want to get this thing running decently. It only has 409 hours on it, and I think I am logically tracing the issues.
Why would a motor blacken the plugs in 2 or 3 min of running? too much fuel or oil? I adjusted the oil rod. Seems to me too much oil wouldn't cause the cutting out issue, unless it was ridiculous amount of course.
Just before the engine cuts out at 2800rpm it momentarily increases rpm on it's own, probably the ecu's last resort before cutting off from a lean condition? I think they call that flaring?
I would bite the bullet and purchase anything if I was SURE it was the issue, but chasing parts is breaking the bank.
I suspected the HP pump is failing, but wouldn't that show lower pressure at all times?
If the HP pump was running out of fuel from the VST, why would I have to clean the black off my plugs so quickly? Unless, the ECU is dumping oil to correct???
Any help here is GREATLY appreciated.
