Fuel problem help
 

Hey guys, may be a shot in the dark as most of you are Merc folks...

I have a 97 Chris Craft with the Volvo 5.7 GSI motor. It is the GM TBI system with a low and high pressure pump. Bought the boat last year around this time. Has ran great, but seems to be having a fuel issue. Started acting up a few days ago with a miss at about 3000 rpm at operating temp, then yesterday it began a slight hesitation on take off. I noticed an odd intermittent fuel pump sound at idle before taking off and think it may be related. Being new to the boat I have heard the pumps kick up in noise from time to time during low speed operation,but thought it was normal...I have read a lot of posts about both the pump screens and the water cooling lines becoming clogged. I pulled the inline filter last night and dumped it in a clear glass, no water but there was some brown particles and sediment present. I am going to start with the obvious clogging issues first then move on to pressure testing if not succeOssful. Just wondering if anybody has had any experience with these motors. Thanks, Rob

Wanted to add a few more observations. I recently used 87 octane due to the price of gas. Manual calls for 89, but says 87 can be used at a slight performance decrease. Noticing the miss and hesitation, at about a half tank I topped off with 93... Not sure if it matters, but I plan to stick with 89 going forward. And it has been extremely hot here in Michigan. Engine has been running at about 175 and seems ok as far as heat. The pump noise... Boat starts fine, cold or warm... When I leave the dock you can hear what sounds like the fuel pump "kicking on" it is very noticeable, but not crazy loud. It does the same thing a few times during normal operation, usually off plane at low speeds. Not sure if you are supposed to hear these pumps operating? Thanks