Hammerhead missing out

[barefootski]

On our past two outings, my engine has started to miss out when taking off. When accelerating, it will hesitate then go. After about 25 mph, it runs fine. It has never done this before. This spring at the start of the season, I had my dealer (not where I purchased the boat since it was a promo boat) do the 100 hour maintence, install a second fuel pump to prevent vapor lock which has not occurred again, and change the fuel filter. My engine also smokes (coming out the exhaust at idle). I have had the dealer run diagnostics but they tell me there is are no abnormal codes that show up. I'm wondering if the engine is running too rich and how do I get the problem fixed. I'm about 3 hours away from the dealer so it's not like I can just drop the boat by for a check-up. Aslo, my engine warranty expired this summer as my boat is a 2006 model.

Thanks for any advice and input.

[electricjohn]

Most common cause of hesitation at takeoff is a vacuum leak, corroded distributor cap, or a lethargic MAP sensor. None of which show up in diagnostics.

[BillFooter]

Michael,

First I think you need to clean the battery cable ends and tighten them so they make good contact with the battery terminals. Once last weekend your boat wouldn't start because the battery cables weren't tight. The ECM needs a good steady ground and uninterrupted power without spikes from loose connections. The smoke Michael is talking about is black smoke from very rich fuel mixture at idle, not grey smoke from oil. This boat has always smoked at idle since Mike got it , but sometimes it is worse than others.

Since the bogging down on take off and missing out is sporadic, I don't think it would be the distributor cap. I do think it might be a sensor that may be going bad or have a loose connection. Michael's boat has the 383 Hammerhead.

[electricjohn]

A faulty coolant temp sensor would force the ECM to run the engine rich, therefore the smoke on take off. It would have to nearly fail to throw a code.

[Baddog]

A faulty coolant temp sensor would force the ECM to run the engine rich, therefore the smoke on take off. It would have to nearly fail to throw a code.

Electricjohn is right on the money. I had this exact problem and a new temp sensor fixed.

[barefootski]

Thanks for the help!!