View Full Version : No idle 6.2

Classic Doddy
08-23-2010, 03:38 PM
Good afternoon Donzi.net

My 2004 18' Classic with a 6.2 will not idle. It happened last week and here is how the story goes. I was putting through a few canals last week and I though it was running a touch rough, I could smell the exhaust, and it is always so perfect. When I was leaving the canal, the warning "beeper" went off, I checked all the gauges (perfect) and looked under the hatch to check for belts, hoses, water and such - all was perfect. I was nursing is back to the docks when it just quit. It took a couple times to start it and when it did I had to go 1500-2000 rpm to keep it running. Running really rough.

I thought it may be just out of gas, but the gauge reads true, or at least it has, when it is on the trailer, and leaves me with 1/4 to 1/3 tank. I was able to run it in reverse without it stalling as well. I do not know where the pickup in the tank is. I doubt I'm this stupid, but I'll be filling it up when I have the chance and trying it again, but on the trailer in the water.

Any ideas or has anyone else had this sort of problem. :confused:

Thanks again, Dodman

08-23-2010, 04:00 PM
Got a water separating filter? Fuel injected or carbed?


08-23-2010, 04:07 PM
Your symtoms could be caused by this:


My '86 Minx. I replaced both risers/elbows (Merc Cast Iron) at about 13 years old because..as it turns out, one was pissing water into the cylinders (rust-pinhole) on the PORT side. (@190 hours)

Everything is fine until last season (24 years old). More pissing. I replaced BOTH the Riser And the Manifold (PORT Side) because I figured the manifold was probably about due. Lets do both. What a Real PITA that was. Broken bolts......... So now it's all done.

NOW.. After the fact..I take a GOOD look at the old riser which seemed to be fine on first inspection off the old manifold...prior to replacing ALL. The F-in riser had a pinhole. The original old manifold was NOT the problem.

This boat is raw water cooled...and flushed after every use.

Pull some spark plugs and look for Water. Replacing an elbow is pretty easy. :yes:

Classic Doddy
08-23-2010, 05:21 PM
It's a 6.2 mpi and freshwater cooled. It may have a factory strainer. Thanks.

08-23-2010, 06:09 PM
I would take a look at the water-separating filter. Pull it and dump it in a pickle jar. look to see if there is water in the fuel.
I would then pull the spark plugs and start inspecting. Hopefully, no water in the engine like what DonziJon posted.


08-23-2010, 07:41 PM
It's a 6.2 mpi and freshwater cooled. It may have a factory strainer. Thanks.

I think someone noted that no matter what ...the elbows are raw water cooled. The elbows will get pinholes sooner or later. Whatever.........:nilly:

08-24-2010, 11:01 AM
Change all fuel filters, sounds like a fuel delivery problem.

08-24-2010, 03:51 PM
fuel filter first.

if that doesn't work it could be the fuel cooler. it doesn't seem like the most reliable part and I can't say if it is raw water cooled on the Horizon or if it is part of the cooling system simply because of the location it wouldn't surprise me if it was raw.

smell any gas in the compartment? sometimes they leak on the outside.

08-25-2010, 04:14 PM
Do a fuel pressure test at the Schrader valve between the 2 rails on the intake. It should be 43 PSI. Engine does not have to be started but fuel system must be energized by the key switch just long enough to get the total boost.

Classic Doddy
08-29-2010, 08:39 PM
Thanks for the input - It ended up being an IAC