happy_flyer
Cadet
- Joined
- Oct 9, 2007
- Messages
- 16
Hello all,
NOt sure if I have one or multiple problems. My '81 Sunrunner with OMC 3.8 V6 ( 650 hours on it )... starts and idles no problem. Idles at 650-700, first turn of the key when cold. Let it warm up, move out of the no-wake zone, want to open her up but seems to want to die between 1500 and 2000rpm. If I go through this range slowly, pause at around 1800, it seems to "catch up", otherwise it will die on me. Once past this it seems to accelerate quite well, but just this last week started to notice a little pinging at full throttle. I really noticed yesterday when I did the samaritan thing and towed a stranded couple a few miles back to the dock ( poor folks..had been stuck for some time after they blew a hose and sprayed oil everywhere ). Anything over 2000 RPM would ping. So, under load, it pings. Could these symptoms be related ? A few weeks ago I replaced all fuel lines, filter/seperator and the fuel pump. Before I noticed the pinging, I was about to get a carb rebuild. but now I am having second thoughts. Just for fun, I played with the idle screw a little and noticed not a lot of difference in RPM regardless of turns in either direction. It would either go from running a bit rough at 600 RPM to positively humming at 750 and this would be with two complete turns in or out. I have sprayed carb cleaner in 3 times, added fuel system cleaner and also an octane booster. This weekend ( same day as towing boat ) I filled up with regular 87 fuel.
Kind of related... while checking the supply system, I pulled the check valve at the fuel tank ( one way valve )...should I be able blow cleanly through the correct way ? It seemed to be a bit of a struggle...like not that easy to get a smooth flow of air.
Sorry for all the details...just trying to paint a clear picture of what is going on. Any help or suggestions greatly appreciated. Thanks !
NOt sure if I have one or multiple problems. My '81 Sunrunner with OMC 3.8 V6 ( 650 hours on it )... starts and idles no problem. Idles at 650-700, first turn of the key when cold. Let it warm up, move out of the no-wake zone, want to open her up but seems to want to die between 1500 and 2000rpm. If I go through this range slowly, pause at around 1800, it seems to "catch up", otherwise it will die on me. Once past this it seems to accelerate quite well, but just this last week started to notice a little pinging at full throttle. I really noticed yesterday when I did the samaritan thing and towed a stranded couple a few miles back to the dock ( poor folks..had been stuck for some time after they blew a hose and sprayed oil everywhere ). Anything over 2000 RPM would ping. So, under load, it pings. Could these symptoms be related ? A few weeks ago I replaced all fuel lines, filter/seperator and the fuel pump. Before I noticed the pinging, I was about to get a carb rebuild. but now I am having second thoughts. Just for fun, I played with the idle screw a little and noticed not a lot of difference in RPM regardless of turns in either direction. It would either go from running a bit rough at 600 RPM to positively humming at 750 and this would be with two complete turns in or out. I have sprayed carb cleaner in 3 times, added fuel system cleaner and also an octane booster. This weekend ( same day as towing boat ) I filled up with regular 87 fuel.
Kind of related... while checking the supply system, I pulled the check valve at the fuel tank ( one way valve )...should I be able blow cleanly through the correct way ? It seemed to be a bit of a struggle...like not that easy to get a smooth flow of air.
Sorry for all the details...just trying to paint a clear picture of what is going on. Any help or suggestions greatly appreciated. Thanks !
