I have a 2005 Mercruiser 5.0 Bravo III. Took boat out for first run and started fine, idled fine, all seemed well until I tried to accelerate past no wake speed. When I would open it up, motor would cut out and seemed to be bogged down, eventually I was able to get up to about 20 mph max. If I tried anything else, engine cut out, bog down. Took it to mechanic who said plugs were fouled, I needed a tune up and all was fine. Next time out, boat wouldn't start until I did a throttle only start about 3/4 down, but then fired up. Ran great w no issues and since I was worried about stale fuel, ran it almost dry. Next trip out, fueled up w/ all new fuel and boat started on the ramp, but then died. Couldn't get it started for 10 min. Tried throttle only again process again and it fired up and ran fair, but was idling low and cutting out, eventually stalling every time I got to idle. Since I was 7 hours away on vacation on a nice lake (minoqua in WI), kept starting using new method and did quick shifting to keep in gear since when it was in gear, it ran fine. Only in idle it would stall, otherwise was running great.
When I got home I took boat in to mechanic this week and he suspected it was IAC control, but he wasn't done testing. He called me later and said he noticed plugs were fouled again (just had new plugs one month earlier) and told me they think it is caused by rich fuel mixture issues and went on to tell me there is a common problem with the merc gen 3 cool fuel modules and thinks paint is getting in the fuel from the paint coming off the cool gen 3 fuel module. Estimate provided was $3700 for new module and mechanic also said it include replacing fuel injectors at $250 * 8.
Lots of questions, but mostly, is the mechanic just going off of what he might have found, researching like I am or how can I tell it is this issue?
Can I just replace the fuel module or do I need to replace the injectors as well ($1700 vs $3700). Boat runs great except at idle and like I mentioned, already replaced IAC and associated filters.
How can I be sure the module needs replacing and I am just not getting $crewed out of my hard earned dollars?
Please help. Any suggestions appreciated.
When I got home I took boat in to mechanic this week and he suspected it was IAC control, but he wasn't done testing. He called me later and said he noticed plugs were fouled again (just had new plugs one month earlier) and told me they think it is caused by rich fuel mixture issues and went on to tell me there is a common problem with the merc gen 3 cool fuel modules and thinks paint is getting in the fuel from the paint coming off the cool gen 3 fuel module. Estimate provided was $3700 for new module and mechanic also said it include replacing fuel injectors at $250 * 8.
Lots of questions, but mostly, is the mechanic just going off of what he might have found, researching like I am or how can I tell it is this issue?
Can I just replace the fuel module or do I need to replace the injectors as well ($1700 vs $3700). Boat runs great except at idle and like I mentioned, already replaced IAC and associated filters.
How can I be sure the module needs replacing and I am just not getting $crewed out of my hard earned dollars?
Please help. Any suggestions appreciated.