2005 Sportster 4-tec 215 still won't start when hot

[ple999]

After running perfectly, then parked for a while, it will not restart for an hour or more. It turns over but won't crank. Have determined that the TOPS valve is sticking closed when hot. So, I decided to remove the sealing disks and let the ECM think the valve is working. When I opened the oil separator, I found deposits of a whitish gunk. Dipstick is normal. Should I be alarmed? See photos.

 

[ple999]

 

[ple999]

Yes, I've been following the advice of the forum members for month: new fuel pump and filters. cleaned the engine ground connection and added a 2nd, larger ground cable, etc, etc. The local shop said it's a common problem. The test, when it won't start, is to pull the dipstick and listen for a hiss of pressure release. It hissed. Then it started immediately. I'm now concerned about the white gunk in the oil separator.

 

[Corylee73]

Another possible issue that can cause no start when hot is a leaking exhaust manifold. Once the boat is ran a while on the water then turned off and left floating a while, water can leak back into the exhaust valves and into the cyls. This will cause hard or no start till it sits a while. Just another thing to consider.

 

[jrsharpebc]

Ple999, did you ever get this solved? I’m running down the same issue with my 06 Challenger w/ same engine.

Corylee73, leaking how? Is there a check valve or something in the exhaust chain to keep water out?

 

[ple999]

Yes. It was the TOPS valve sticking closed when the engine was hot. That causes an overpressure situation that prevents starting. I pulled the TOPS, removed the sealing disks and reinstalled it. That way the ECU still "sees" it, and the engine started normally.... Until the seized up for other reasons. If I get another boat, it will be a "normal" one.

 

[jrsharpebc]

Yes. It was the TOPS valve sticking closed when the engine was hot. That causes an overpressure situation that prevents starting. I pulled the TOPS, removed the sealing disks and reinstalled it. That way the ECU still "sees" it, and the engine started normally.... Until the seized up for other reasons. If I get another boat, it will be a "normal" one.

Thanks for the update! On mine CanDoo doesn’t report that the TOPS valve has changed state when hot but I wonder now if it’s a false reading…ie the valve is actually f***ed but the ECU doesn’t see it that way. Really appreciate the insight.

John

 

[ple999]

The local shop told me how to diagnose it a sticking TOPS valve: When it wont start, pull the dipstick loose and listen. If there is a hiss, that the pressure releasing and then it should start.