High Altitude Issues with 454 Mercruiser

gengiant

Member
exMember
Joined
Nov 4, 2004
RO Number
15658
Messages
22
I took the boat up to Lake Tahoe (el. 6,300 feet) last weekend and had all kinds of engine problems. This is a fuel-injected 454 Mercruiser. The following where the symptoms. Once running (no starting problems) it would often die on me when idleing. The idle seemed to run real low. Under no-load conditions (out of gear) it would rev up well beyond 4,000 rpm. In gear, however, it would simply bog down at 2,200 rpm. At low rpm (~1,000 rpm) in gear it apeared to be running a bit rougher than usual. We had the boat out the weekend prior at sea elevation with absolutely no problems. I will take the boat out this coming weekend on a local lake at sea level to check if this was just an altitude problem. Does anyone have any thoughts on what may have caused this malaise?

Thanks!
GG
 
Back
Top