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Boat Repair/Hard starting 7.4L MPI engine

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Expert: Jeff Grigg - 1/27/2008


Question
I have a 1999 Mercruiser I/O with a 7.4L MPI engine.  In cold weather (below 60), it cranks for 5 or 6 seconds before starting, then it stalls.  I restart and it runs for about 5-6 seconds and stalls again.  When I restart the third time, it runs fine. Acceleration and WOT seem correct. While it still takes several seconds to start in warm weather, it doesn't stall.  What should I check for?

Answer
Make sure you aren't opening the throttle when starting. What you describe isn't that unusual. You need to check the fuel delivery for any leaks, or loose fuel lines. It does take a few seconds to build up fuel pressure.
When you go to start the engine make sure you turn the ignition on for about 5 to 10 seconds before cranking to build up fuel pressure.
Jeff

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Jeff Grigg

Expertise

Can help with most any question related to outboards, high performance, hull repair, rigging, if it floats and uses a motor. From a 9.9 on a aluminum boat to DFI two strokes. Outboard motors are my specialty. I can help with some I/O questions as well. Ratings are the only way we know if we are helping. If you are pleased with the help, please rate us. 20% don't bother reading my answers! If you are not going to read the follow up then why ask? Keep in mind we do this at no charge and are not paid. We do it to help you!

Experience

32 years in the marine business. Own a service facility, in coastal South Carolina certified Master Tech by Johnson/Evinrude, certified Mercury/Force, Tohatsu/Nissan. Former technical director for DMI Pistons. 30 year racing career including 3 APBA Formula V National Championships

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AMTECH, APBA

Publications Written For
Boat & Motor Dealer, Car Classics, Custom Vans (tech articles), Miami News, powerboat racing column

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Certified Master Technician Johnson/Evinrude

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