I have 2002 225 EFI that has been surging for several months now. It only does it when I back out of the throttle as I am slowing down or just enough throttle to keep on a plane or a little faster. Runs strong all other times. This is a fresh rebuild, but it was doing the same thing for some time before rebuild. Any ideas?? Maybe a bad area in the TPS???
That's a strong possibility.... as is "irratic fuel pressure".
Might not be a bad idea to try monitoring BOTH OF THEM (perhaps one item at a time), while "duplicating" the surging condition.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Small hole in fuel line could cause that. Also pick up pump could be needing rebuilt.
Richard
Thanks for the advice. I replaced the fuel line from the tank to the black factory formed line coming out of engine. Rebuild lift pump huh? I'll try that. Thanks again for great site!
Probably not the same problem but my 97promax started lunging at low rpm's and i had a bad battery connection and a ground on the power cable under the clamp right behind where the cable entered the skirt.
Reply With Quote