2003 Seadoo Sportster 4tec

[hontell]

Hi, I have the above mentioned 2003 Sportster 4TEC which was no end of frustration last summer. When we stored it for the winter after summer 2013, she was running great. We ran the gas tank dry, made sure it had antifreeze and put it on the trailer as we do every year. Last spring we filled it with gas checked the oil and coolant and dropped it in the lake. She ran like crap. No bottom end, no top end, stumbled just awful. We added fuel additives, but no change. We pulled the boat, checked the fuel filter, clean. Checked the fuel pressure, dead on, checked the coil packs, all good, pulled each injector, pretty patterns and changed the spark plugs. We even did a compression test on each cylinder and while one was alittle soft it was not out of range. I am pretty sure the engine is running rich, it burned a lot of fuel, and smelled "sweet". Myself and my mechanic can not find a way to lean it out, if that is the problem. Do the injectors need replacement? I know it is not going to run nice this year with out help. Please help! Thank you,
Howard

 

[Coastiejoe]

No chance all your injectors suddenly went bad. It could be as simple as the temp sensor being within operating range but not operating properly. For example, if it registers a cold temp, the MPEMS will hold the injectors open longer. The sensor is testable.


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[hontell]

Thank you, did not think of the temp sensor, since it is original it might just be worth replacing.
H

 

[Coastiejoe]

I posted a chart just yesterday on the ohms it should put out based on various temps. Just board a flight, I'll try to post it before we take off.


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[devonte007]

I think the thread Costiejoe was referring to above is this one: http://www.seadooforum.com/showthread.php?77028-White-smoke-that-smells-like-gasoline-on-a-GTX-Wake-2004&p=461309#post461309

This guy is having a similar problem to yours, and it seems his engine is also running rich.

These engines are computer controlled, so no way to 'lean' it out. If it is running poorly, it is likely due to one or more bad sensors or even a bad ECU... Based on your problems I do not think your injectors are bad. Not too many instances of them going bad, and certainly not all at once.

You mentioned that your exhaust smells "sweet", typically this is an indication that an engine is burning coolant. Any indication coolant is entering the combustion chamber, any loss of coolant?

How do your spark plugs look after the engine has been running?

I might first check for anomalous electrical issues. Seadoo computers do not like electrical problems like low voltage, causes them to do real funny things. Check that the battery is good and you have a good running voltage at the battery, I think somewhere between 13-14v is good.

Next I would check all your grounds and connections to the ECU and MPEM. Check all your wiring and fuses (even the inline hidden ones). Have read lots of posts about corrosion issues causing weird problems. Once your are certain there are no electrical gremlins, then I would start looking at and testing individual sensors related to engine management.

 

[Coastiejoe]

That is the thread I was referring to, thanks.

 

[hontell]

Thank you 007, I read the other thread and all the attachments, very similar, I forgot about the plugs, we did replace with the stock plugs, still wet. I also have the white smoke, but like you and CJ, I assumed it was part of the exhaust cooling. The "sweet" exhaust smell is more gas than antifreeze. We had a cooling problem a few years back, the oil cooler rotted and was sucking coolant into the oil. We will check the water temp sensor, or maybe just replace it to be safe. I will let everyone know what we learn. Again thank you to everyone that has posted an opinion.
H