02 Opti 200 fuel pump probably going bad again

[BoBo]

Recently started having intermittent problem with symptoms exactly like 3 years ago when the high speed fuel pump slowly went bad. Engine cuts out almost completely briefly when runningon plane, usually recovers if I thottle down quickly, then usually its OK for a while. Problem is getting more frequent though and it has happend last 3 trips. I'm pretty anal about only buying 91 octane ethanol free fuel and adding fuel treatment often.

Is fuel pump going bad a common problem with this engine? Could it be some electircal issue related to fuel pump instead of fuel pump itself? The intermittent nature of this problem is a pain for me and repair shop.

[EuropeanAM]

How much does this engine SIT (unused)?

No need for high-test fuel in this engine... it will actually COST you in performance, fuel economy, and results in an incomplete burn (with excessive carbon buildup). Higher octane fuels burn SLOWER and COOLER.

Before jumping to the high pressure fuel pump... I'd take the time to read through the following post, and ensure that ALL recommended items have been addressed (AT THE SAME TIME, with ONLY THE RECOMMENDED COMONENTS):

http://www.bbcboards.net/mercury-3-l...tem-first.html

[BoBo]

Thanks for the reply. It typically sits for about 1-2 weeks between runs, 3 months over winter. But I ran it 5 or 6 times this year before the problem began. Should have mentioned that I had fuel lines and bulb upgraded 2 years ago. I only buy the premium because it is ethanol-free (at least it is advertised to be so at some gas stations down around Lake Ozark). I add Quick-Kleen every other tank full to keep carbon down. The motor starts and idles perfectly.

Is fuel pump issue NOT really a common problem with these motors?

[EuropeanAM]

To date, I believe I have replaced a total of TWO of these pumps (and one of those was certainly caused by degraded, congealed, and just plain NASTY fuel).

If indeed you have failed TWO fuel pumps (as confirmed by testing of pressures at low pressure and high pressure fittings, combined with monitoring flow to pulse pump with a clear piece of hose)... I would be looking for a common CAUSE for the pump failures (fuel quality, fuel starvation, improper assembly, aeration of fuel supply, etc).