What's up with my 502 fueling?
 

Hey folks

My 1995 Formula 271 has an efi 502.
It has done something strange 2 years in a row, but only on my first day out.
Both days I putted around for a while checking things out
and gradually increasing rpms and returning to idle.

Both days, on my first attempt at wot the engine just quit
at about 4000 rpm.
Last year it took the longest time to restart, atleast an hour, I had to get towed to a buoy. It eventually re-started and ran perfect for the day and the rest of the year.

This year , July 1, same shut down but it would restart and stumble badly for about 10 seconds and quit again. Seems to be starving for fuel. After about 20 minutes of restarts and quits, it fired up and ran perfect for the rest of the day.

The only thing I did both days was remove and drain the
spin on fuel separator. The fuel that came out seemed clean, a little bit of crude, but nothing you would expect to cause an issue.

It did not immediately restart after the separator was re-installed either day.

Any ideas on how to avoid this re-occuring next year.

What do you use to fog the engine for winter?

fixx
 

vapor lock..thought merc had a fix for it..like adding a electric fuel pump..

Do have a VST on it. I working on a buddies 95 350 with VST and it's nothing but a POS.

Don't recall the brand, but a product made for fogging.

The boat has VST and a belt driven fuel pump on the front end of
the seawater pump.
Mine may be a vst vapor lock issue, but I only happens once a year, which makes me think there is another issue.
I would like to resolve this for safety if nothing else, no fun bobbing aound with container ships cruising by.

I did a search on vst and there is a screen that can be cleaned, probably won't hurt to do that.

wow 6-7 posts on the opening page for the same thing

Someone has to know the common issue

I doubt it is vapor lock. Vapor lock will usually cause the engine to stall within about 30 seconds of a hot start up.

Mine has vapor locked on me on regular start ups in the morning. I have installed a return to the tank and so far so good.

How did you fog it? Did you fill the filter half up and let it run into the engine or some other way?