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Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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My 99 350 mag will stumble at any throttle change. Once it

Customer Question

My 99 350 mag will stumble at any throttle change. Once it catches up it will run fine. It also is having hot start issues. I'm not sure where to start. The IAC seems to function fine. I keep reading about maybe the TPS, or possibly the MAP sensor. And actually I'm not sure where the map sensor is or what it looks like. Also it seems to be running rich at idle.
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.

Hi Walter, my name is Jason.

If it seems to be running rich at idle maybe it is. Both low compression and high fuel pressure would cause a rich fuel condition. Have you checked engine compression and fuel pressure yet?

Can I also get the serial number on the motor so I can run it and see exactly what you have.

Expert:  Jason replied 1 year ago.

It looks like you read my reply. The website has charged you to speak with me, did you still need help with this?

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