LadyLauraIV
New Member
- Nov 7, 2021
- 24
- Boat Info
- 2002 340 Amberjack 8.1L Raymarine elect.
- Engines
- 8.1L Mercruisers inboard
02 340 AJ 8.1 inboards. 393 hrs. we bought the boat from someone who neglected it.
during sea trial port engine would not get above 3000 rpm and popping thru intake.
indicating to me a lean backfire, the marina owners told me this boat hadnt been taken out in at least a year. it had 3/4 full tanks. i checked fuel pressure at idle and it gave me 36 psi.
so i changed both boost pump and hi pressure pump, coolers, regulators and fuel/water separators in the cf2 system on both motors (im sick that way) took it out and got better power but port side was firewalled at 3600 rpm with some occasional popping, but not as much. while starboard side was a little past halfway at 3600 rpm. we used as much of the old fuel as possible got down to around 1/4 tanks and filled up at our marina. then took it out and had a improvement in power but still popping and throttles still spread. we had very little issues until we turned around to go back, i powered up and got a ton of popping around 3400 rpm out of port motor. got back to the slip and put on the diacom system- no fault codes.
went to the test section and did a induced misfire test at 1600+/- 50rpm and #5 cyl showed no change. pulled plug an found porcelain was white on one side and dark on the other side. did compression test it was 172psi to 180 in all cyl with #5 being 180psi. replaced plug then tested injector pulse at idle no problem there. coil firing nice at idle.
i'm taking her out sat for a full load test with fuel pressure gauge and diacom setup. can anyone think of anything else that i might have missed? Thanks in advance for your input.
during sea trial port engine would not get above 3000 rpm and popping thru intake.
indicating to me a lean backfire, the marina owners told me this boat hadnt been taken out in at least a year. it had 3/4 full tanks. i checked fuel pressure at idle and it gave me 36 psi.
so i changed both boost pump and hi pressure pump, coolers, regulators and fuel/water separators in the cf2 system on both motors (im sick that way) took it out and got better power but port side was firewalled at 3600 rpm with some occasional popping, but not as much. while starboard side was a little past halfway at 3600 rpm. we used as much of the old fuel as possible got down to around 1/4 tanks and filled up at our marina. then took it out and had a improvement in power but still popping and throttles still spread. we had very little issues until we turned around to go back, i powered up and got a ton of popping around 3400 rpm out of port motor. got back to the slip and put on the diacom system- no fault codes.
went to the test section and did a induced misfire test at 1600+/- 50rpm and #5 cyl showed no change. pulled plug an found porcelain was white on one side and dark on the other side. did compression test it was 172psi to 180 in all cyl with #5 being 180psi. replaced plug then tested injector pulse at idle no problem there. coil firing nice at idle.
i'm taking her out sat for a full load test with fuel pressure gauge and diacom setup. can anyone think of anything else that i might have missed? Thanks in advance for your input.