MPI Hard Starting

3

303hound

New Member
Aug 12, 2007
27
porthmadog
Boat Info
Sea ray 210 Br with MTK tower
Engines
5.0 EFI Bravo 3
Hi There wondering if any one could shed any light on a problem i'm having with my 2002 350 magnum. When i come to start the boat it is an absoloute nightmare to get going, coughs back and almost sounds like it's trying to run backwards?? Once i do get it going the engine runs fine and will start up every time for the rest of the day.

Anybody come accross this before?
 
Tried a new IAC and to no avail. It's a bit of a difficult one to diagnose as once it fires up it's fine then i have to wait 2 or three days for the troubles to begin again.

It's had a new distributor cap and rotor which did seem to improve it slightly but not to how it should be.
 
It sure sounds like some type of a cold start fuel delivery problem and will probably turn out to be something electronic like a sensor if the IAC didn't fix it. From what you describe it sounds like the ECM is not getting the message to richen up the fuel flow when the motor is cold. You might want to have a Merc Tech have a look at it or at the very least talk to a Merc Tech about what other sensors might be involved if you want to try replacing them yourself. The extra IAC that you have is still a good "insurance policy" in case it ever fails on the water so I would still hang on to that.

Let us know what you find out.

Dave
 
I feel your pain. I'm still trying to get the dealer to figure out why my spark plugs are fouling. It started with a hard start condition. So, I replaced my IAC, then I changed all fuel filters and the distributor cap and rotor. New plugs were installed and the engine is still hard to start, idles rough and runs rough. So, the dealer is going to come back out and try again. I'll follow up once they determine the solution.

One mechanic said it could be my temperature sending unit/sensor, which sits in the plenum where all the raw water passes through. I ordered one and will try it, if the dealer can't make it down to the boat before I can. I'll let you know how it goes. Meanwhile, good luck and please follow up your issue when yours is resloved. Thanks!

Eddie
 
cheers guy's will keep at it. Hate it when an engine has the upper hand on me.
 
Ignition coil possibly?
 
All,

I went down to my boat to search for arching between plug wires or the coil (at night) after hearing from the dealer that my engines are fine, according to their computer. Well, I saw arching all over the ignition coil.

I think the insulation wears down on those things and current just flies out the sides after some years of age. I was debating trying to reinsulate the coils, but I'd rather have new ones I think.

In any case, I just wanted to add to another list of things to look for when diagnosing hard starting or rough running engines. This is easy to see at least.

Eddie
 
have they done a fuel pressure check? fuel pressure regulator? injectors leaking down?
got to go back to basics. fire fuel and compression..... forget that it is an mpi.
 
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