2004 Sportster 4-tec Starting issue

[wmrath]

I just got this little boat hoping I can fix a no start issue on it. Currently, I put the DESS on, when I push the start button, it tries to crank for about 4 secs then stops. It gives me four quick beeps which I read indicates the DESS key has been plug in too long. If I just try again without disconnecting the DESS for about a minute I get about 1 second of crank and the 4 quick beeps.

A little history, previous owner got it, replaced the battery, starter Solenoid, and fuel pump. Got it running and took it out one time.

I originally thought the four quick beeps indicated the boat was not in neutral. I pulled the throttle assembly and pulled out the neutral switch (what a pain). I hard wired the neutral switch and get the same result. When I disconnect the wire from the switch (open switch) I get nothing except the 4 quick beeps when I push the start button (the real "not in neutral warning" ). Which tells me the switch was not bad.

So I am back to my original question: What would cause it to crank for a few seconds on the first try and then cranks for barely a second any subsequent attempts if I do not pull the DESS key for a few minutes and reconnect again?

I am leaning toward a bad MPEM but do not know how to test it.

Anyone have suggestions?

 

[MacSeaDoo]

The first question i have would be can you get it to turn over consistently by jumping the solenoid? If you can, you eliminate the possibility that it can't physically maintain a start condition.

Next, check the start button. Pull it out and check for reliable operation.

Then, I would move to the grounds. Find them all and make sure they are in perfect shape. If a ground is bad for the ecu, it can reset the ecu during a situation like a start. (High draw)

 

[wmrath]

Thank you for the reply...you have given me a starting point. I went out today (before I saw this post) and replaced the 675 CCA Marine battery the previous owner had put in it with the 400CCA battery recommended. I then tried to crank with the same results (No surprise). I then pulled the spark plugs and ran as good a compression test as I could (hard to tell when it will only crank for a few seconds). I was satisfied with the 130 PSI I saw on each cylinder with only about 2 seconds of cranking. I will try jumping the solenoid and let you know how that pans out. I will also pull the start button, and move toward the grounds. I am leaning toward a ground issue now. I will let you know how things pan out....thank you again!

 

[wmrath]

This was quick...jumped the solenoid and cranks fine. It cranks consistently that way. I have to get to work now so testing the start button and checking grounds will have to wait. I am excited for the progress though!

 

[MacSeaDoo]

No worries, seems like a lot of bo start issues on the forums these .

Hope you figure it out.

 

[wmrath]

Follow-up. I checked the ground. It was not bad but I cleaned the terminals and the engine block. Put it back together. The boat started this time but only ran for about 3 seconds (about the same amount of time it would crank without starting on the first try). Then the very short cranks until I turn the battery off and on again. Then it will fire and run for about 2 or 3 seconds on the first attempt to start it.
Any ideas?

 

[wmrath]

Follow-up number two. I replaced the ECU (MPEM) and that resolved the cranking issue. It will now crank as long as I want to hold down the button. However, it still will not start. It will start and run for a few seconds with starting fluid. The previous owner replaced the fuel pump. I am going to check it just in case. I also plan on checking the fuel filter, fuel pressure, and injectors as well. anyone have any suggestions?