lowdrag
07-01-2006, 01:44 AM
Ok, I've got a new 21V with just over 30 hours on it. I've had an issue with the 325 hp injected motor from day one. When it runs it runs great, but at times it has starting issues. The starting problems only occur after we've been out running the boat for a while, boarding, running around etc. When we shut the engine off for a couple of minutes to change riders there is no problem getting it started. However, if we sit for an extended time, an hour or more, it won't start. It will usually start and idle rough for 10 or 15 seconds and then die. After that, it just cranks and makes no attempt to start. The only thing that seems to work is to open the engine compartment, turn the blower on, and let it cool down. Usually after 15-30 minutes it starts and runs great.
I've checked for spark when it won't start and it seems to be fine. The ignition module has been swapped out but that did no good. My dealer has been great to me trying to figure this out but he's stumped a little as well. Every time I've had it there he has trouble reproducing the problem. However, when I'm out I'm pretty much assured this will happen if it sets for too long with a hot motor.
We both agree that it sounds like classic vapor lock symptoms but neither of us have heard of anyone else with an '06 having this issue. One time that he did have it, he said that the throttle position sensor had put out some trouble codes that he cleared with the computer. The last time I had this happen, I thought of that while trying to get it started. I unplugged the sensor that is hooked up to the throttle cables (it's called something similar to the throttle position sensor, but that's not it exactly). With the sensor unplugged, it started and ran fine. However, you then need to shut the motor off and plug the sensor back in in order to run the motor at anything above idle. I'm not sure that this was anything more than coincidence and that it wouldn't have started on its own without doing this.
The last time I had the boat out, I had mounted a fuel pressure gauge on the fuel rail to check for vapor lock. In order to do this you need to leave the big plastic shroud on top of the motor off. Under similar circumstances the boat started, idled a little rough for about 10 seconds and then ran fine. I'm thinking at the moment that it could be vapor lock that is compounded by the plastic shroud on the motor acting as a big heat retention/reflection device. Maybe the shroud keeps more heat trapped around the fuel rails causing the fuel to vaporize? I'm also guessing that when the dealer tried to reproduce the situation, he had also taken the shroud off prior to running the motor which is probably why he could get it to happen for him.
Anybody have any similar problems? Any suggestions, thoughts, or ideas would be greatly appreciated as this problem is really bothering me and is cutting into my enjoyment of what is an otherwise great boat. Brian, any thoughts?
I've checked for spark when it won't start and it seems to be fine. The ignition module has been swapped out but that did no good. My dealer has been great to me trying to figure this out but he's stumped a little as well. Every time I've had it there he has trouble reproducing the problem. However, when I'm out I'm pretty much assured this will happen if it sets for too long with a hot motor.
We both agree that it sounds like classic vapor lock symptoms but neither of us have heard of anyone else with an '06 having this issue. One time that he did have it, he said that the throttle position sensor had put out some trouble codes that he cleared with the computer. The last time I had this happen, I thought of that while trying to get it started. I unplugged the sensor that is hooked up to the throttle cables (it's called something similar to the throttle position sensor, but that's not it exactly). With the sensor unplugged, it started and ran fine. However, you then need to shut the motor off and plug the sensor back in in order to run the motor at anything above idle. I'm not sure that this was anything more than coincidence and that it wouldn't have started on its own without doing this.
The last time I had the boat out, I had mounted a fuel pressure gauge on the fuel rail to check for vapor lock. In order to do this you need to leave the big plastic shroud on top of the motor off. Under similar circumstances the boat started, idled a little rough for about 10 seconds and then ran fine. I'm thinking at the moment that it could be vapor lock that is compounded by the plastic shroud on the motor acting as a big heat retention/reflection device. Maybe the shroud keeps more heat trapped around the fuel rails causing the fuel to vaporize? I'm also guessing that when the dealer tried to reproduce the situation, he had also taken the shroud off prior to running the motor which is probably why he could get it to happen for him.
Anybody have any similar problems? Any suggestions, thoughts, or ideas would be greatly appreciated as this problem is really bothering me and is cutting into my enjoyment of what is an otherwise great boat. Brian, any thoughts?