Help me diagnose please

[mainiak1]

I have a 1998 2100i 350 mag mpi. I bought the boat last fall so I don't know if it always did this.
When we go skiing and stop the motor to switch skiers the motor sometimes will not start. It turns over and will almost catch but not quite. I thought it might be vapor locked like some people have experienced, so yesterday I ran the blower the whole time. Seemed to start up quicker this way but I had to wait a minute on second try it started. When it does start it looks to have been flooded as black smoke out the back and smell of fuel. Does this sound like vapor lock? I also have a problem when picking up a skier this has happened only a few times. When I throttle hard to pick up a skier it stalled. When it does start back up it acts like it was floded again black smoke,fuel smell etc.

I did not have this problem in the spring so heat definately has some thing to do with it. The boat has never left us stranded just annoying and embarrassed. Other than this problem the engine runs superb. All suggestion will be appreciated.

[whitlock87]

The blower is only to keep fumes out of the engine compartment.
As far as know, the blower will not affect the way your engine runs, it is a safety device to help prevent the boat from exploding at time of start up.

If the engine has black smoke, then you are running to rich.

You might just need a good tune up. (That includes a throttle body service)

[Tige M.D.]

dave, he was using the blower to cool down the engine compartment. this will sometimes help when the weather is very hot and the engine is just heat soaking in the compartment.
you could have a leaking injector or a ignition sensor failing. it tends to break down in the heat, once it cools off if is fine until it gets hot again. the is usually followed shortly by complete failure.

[whitlock87]

Greg
If you are running the blower (which takes air out of the engine compartment) and drive the boat at rpms over 3k, can you get in to a situation where you are starving the engine for air?

What is your thought on changing out the flex tube in the front lockers to PVC pipe (to get better airflow on my switch V?

And last question
How’s the new job

David

[raythompson]

Originally posted by whitlock87
If you are running the blower (which takes air out of the engine compartment) and drive the boat at rpms over 3k, can you get in to a situation where you are starving the engine for air?

That is never going to happen. The incoming vent can provide more air than the engine can consume and the exhaust fan can pull from the compartment.

It sometimes helps to run the blower to keep fresh, cool, air coming into the engine compartment to help cool the engine down. The primary purpose is fume exhaustion, but it does have a secondary use also.

[whitlock87]

So it sound like it might be a good idea to run the blower all the time in hot places.
Or should I only run it all the time if I am having problems?
Thanks Daivd

[mainiak1]

Tige MD,

Thankyou for responding, I went skiing today and when I was in the water I noticed on start up black smoke which clears away quickly. Any way to diagnose that injector? Where is the ignition sensor? Any way to test?

Thank you again for your time.
mainiak1

[raythompson]

Originally posted by whitlock87
So it sound like it might be a good idea to run the blower all the time in hot places.

It certainly will not cause any problems and might help in some small way other problems. Seems like a win-win situation. If the blower wears out they are cheap to replace.

I run mine all the time, from the time I get to the ramp until I am off the ramp (bent prop and chopped bunks and all.)

[ghollow]

Hey mainiak 1,

Check your distributor cap. I had a problem similiar to this and discovered my distributor cap had a great deal of corrosion. I replaced it and the rotor and it solved my problem.

[mainiak1]

ghollow:

I will check thanks.

[mainiak1]

ghollow:

I checked the distributor cap and found it to be corroded. The cap and rotor was original. I also found the plugs to have been gapped at .052 I gapped them at .045. I will change the distributor cap and rotor.
I will not get a chance to take it to the lake till Saturday. I'm crossing my fingers.

[mainiak1]

The cap and rotor did not fix it. While it did start up it wanted to stall on take off had to back of throttle for a second. The motor was off for 30 minutes. I think it is vaporlocking. Does anybody know what fuel pressure reading I should be getting?

Thank you,
mainiak1

[TeamAllen]

I would do a search (at the top of the page) for fuel pressure. I believe it should be 30psi. One time I remember a thread about there being other fuel filters down the line. And another guy, it was his ignition switch. You never know. The other posts will probably help. Also try searching vaporlock.