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View Full Version : 1995 Maristar loading up?


threadbaron
08-03-2009, 04:41 PM
I have a Maristar 200 and over the past 2 summers it "started out" with a problem that has now gotten bigger. It has always seemed to run a little rich with the back of the boat always getting a little black and dirty. Last summer, usually after idiling around for a good while, when we would turn off the boat if it did not start of the first time, it may not start. It seemed to be loading up with gas and I found out by taking off one of the injectors it would fire right up. This only happened every few weekends but it is an issue.

Now it has started running fine but then it suddenly starts losing power and will not go above approx 2000 rpms. I let it sit for a while and then it started and ran fine. It idid it again and this time it still starts slowing down from running fast (around 3000 rpms) and gradually just slows and slows. Whne you try to back off the gas and then give it more, it just chokes it down.
I tried to review the threads already answered and see if it was applicable to me. I did change the plugs and fuel filter just last week and this did not fix it. I am curious about the injectors and a statement that they need a "good cone". Mine seem to be steady but not sure if they would be described as a "good conical shape". If I do need ot clean the injectors, would a good cleaner in with a tank of gas do the trick or would i need to do something else?
Any help? I will be glad to run down anything needed for a better picture if needed. Help!

lilsumo
08-04-2009, 02:56 PM
what did the old plugs look like? You have described a rich and lean condition and poor spark all at the same time.

Check for vacuum leaks, it may be running lean and be dumping fuel in to the engine to compensate.

Check your fuel pressure, to little or to high. The computer is programmed at a certain pressure and if it's off it doesn't know, so when you ask it for more power, it's just not there and it bogs down or has a hesitation in it.

These are simple things you can do on your own with very little expense and time.

JimN
08-04-2009, 04:06 PM
I have a Maristar 200 and over the past 2 summers it "started out" with a problem that has now gotten bigger. It has always seemed to run a little rich with the back of the boat always getting a little black and dirty. Last summer, usually after idiling around for a good while, when we would turn off the boat if it did not start of the first time, it may not start. It seemed to be loading up with gas and I found out by taking off one of the injectors it would fire right up. This only happened every few weekends but it is an issue.

Now it has started running fine but then it suddenly starts losing power and will not go above approx 2000 rpms. I let it sit for a while and then it started and ran fine. It idid it again and this time it still starts slowing down from running fast (around 3000 rpms) and gradually just slows and slows. Whne you try to back off the gas and then give it more, it just chokes it down.
I tried to review the threads already answered and see if it was applicable to me. I did change the plugs and fuel filter just last week and this did not fix it. I am curious about the injectors and a statement that they need a "good cone". Mine seem to be steady but not sure if they would be described as a "good conical shape". If I do need ot clean the injectors, would a good cleaner in with a tank of gas do the trick or would i need to do something else?
Any help? I will be glad to run down anything needed for a better picture if needed. Help!

If you see a conical spray pattern and your flame arrestor is clean, check your ECT (Engine Coolant Temperature) sensor. MattG had the same problem. If it starts by disconnecting one injector, try cracking the throttle a little- it will start when you do this because you're accomplishing the same thing-more air for the amount of fuel being delivered.. With a bad (reading high resistance) ECT, the ECM thinks the temperature is extremely low and dumps a lot more fuel.

ahhudgins
08-05-2009, 12:15 AM
What's the "correct" way to check the fuel pressure on the TB? When I was having the starting issue on my 95, I wanted to monitor the pressure but it's a solid fuel line from the pump to the TB. Is there a port where that this can be done when the enging is running. I do machine repair for a engine builder (Sonny's Racing) and they told me that they could make me a fuel line with an adapter for a fuel gauge.

JimN
08-05-2009, 10:35 AM
What's the "correct" way to check the fuel pressure on the TB? When I was having the starting issue on my 95, I wanted to monitor the pressure but it's a solid fuel line from the pump to the TB. Is there a port where that this can be done when the enging is running. I do machine repair for a engine builder (Sonny's Racing) and they told me that they could make me a fuel line with an adapter for a fuel gauge.

Once you get the Shrader valve on the fuel line, you put a towel next to the valve to catch any gas that may spray out (if the key has been turned on or the motor has been run recently), attach the gauge and turn the key ON. You should see the gauge move but it won't go to its maximum. After the priming cycle, turn it off for at least 5 seconds, turn the key ON again. This time, place the end of the bleeder line into a clean clear container and press the bleeder valve so you can purge any air from the gauge. Next time you turn the key ON, it should reach it's maximum but if it's not close to what your motor should see, repeat the cycle.

The MC recommended pressure tests are at Key ON/Engine OFF, Idle, 2000 RPM and WOT. The 2000 RPM and WOT tests are done under load, on the water. Never rev the motor to high RPM without being under load.

If you should have a performance issue that seems to involve the fuel pump/pressure, you should run it on the water and have someone monitor the gauge. If you see any drastic changes in pressure, you will need to find out why.

The shop may be able to silver solder the valve onto the line.