- Mar 11, 2013
- 6,946
- Boat Info
- Sara Belle
2005 Weekender 215
- Engines
- Mercruiser 5.0 mpi, Bravo III
So I guess you won't be 'liking' my post?The IAC is not a sensor. It is a PWM output controlled solenoid/actuator. Sensors are inputs.
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature currently requires accessing the site using the built-in Safari browser.
So I guess you won't be 'liking' my post?The IAC is not a sensor. It is a PWM output controlled solenoid/actuator. Sensors are inputs.
As per your suggestions above, I had the IAC and fuel pressure tested, and they are normal.
We could not duplicate the condition at my dock - I suspect the engines need to be run at normal speed and temp for a while.
I did take the boat our for a run, but turned on the blower for about 5 minutes before shutting down the engines. This seemed to solve the problem.
I was also told the problem could be with the fuel blend. It seems the blend is changed depending on use for summer or winter. I could have a winter blend - which is more volatile - but it could be causing a vapor lock because I live in Florida and we are having a warm winter.
In any case, I would like to thank everyone for your help.
Thank you for your response, but now there is even more to the story. I brought my boat up to Tampa yesterday, and when idling into the marina the port engine quit. It would start immediately, but after several seconds it would again quit. However, if I ran the blower then the engine would start and continue to run. I am anticipating an uneventful trip home today, but would like to get this issue resolved, especially since it only happens on the port engine.This is actually pointing more towards vapor lock. your engines should be new enough that the low pressure pumps are already installed to help "overcome" this. I am in Bradenton as well. I know all too well the virtues and drawbacks of warm weather vs. cooler temps North of here.
Thank you so much for this photo.Right on top of the engine.
View attachment 80553
I will certainly change out the IAC’s to see if that is the problem. However, since the blower keeps the ER cooler, which seems to solve the problem, that would indicate whatever is being cooled is not attached to the engine, since it then has more cooling air blowing around it. If that is the case, what could it be that’s getting hot?Right on top of the engine.
View attachment 80553
Thank you for the photo of the IAC valve. I have tried to change out the two I have, but I'm unable to disconnect the electrical wires. The wires go into a plastic cap, which fits over the plastic electrical connector connected to the IAC. I imagine the connector must be held securely in place because of all the vibration, but I have not been able to figure out how to disconnect. Any thoughts would be helpful.Right on top of the engine.
View attachment 80553
I did not take you advise on flushing the engines because both have always (I have had the boat about 10 months now) run at 160 degrees.Flytrade,
I had a similar (read almost identical) on my 98' 330. After a bit of trouble shooting, I came to the conclusion noted above about vapor lock. My solution was a multi-step approach.
First, I checked my impellers, they were in horrendous shape. Replaced and back flushed the trans cooler. Lots of rubber pieces washed out. Slightly better flow from the exhaust, but still not where it should be. Problem reoccurred after first couple days out.
Next, read up on barnacle and tiger mussel growth on the inside of the cooling system. Read up, and ended up buying Barnacle Buster to flush the system. It's not cheap, but as soon as it had run through the blue solution turned almost black. Ran it through a cycle until risers got too hot to touch comfortably and left it sit in the engine for 4 to 5 hours. Re-hooked up the lines to the exhaust and through hull and started the boat. "Black gunk" came out of the exhaust that should have been clean water. After a minute or so of running it turned clear again. Did the same thing to starboard the following day. Same results. The engines are now running significantly cooler (and quieter) due to additional water running through.
I can run for multiple hours at the 3k RPM range, pull over, open engine hatch, and get down on the engines without it being too hot to touch. Engine bay is also significantly cooler.
If vapor lock issue persists, I would check the cooling system.
Nic
I did not take you advise on flushing the engines because both have always (I have had the boat about 10 months now) run at 160 degrees.
However, I did switch out the IAC valves and took off the cover to the flame arrester on the port engine, and that seems to have made a difference. I'll have to wait to get the boat out for more testing, but at least I'm hopeful.
And again, thanks to all that have responded.