Engine won't get boat on plane - ignition issue?
06-18-2014, 06:14 AM
#23
I had a similar issue once, running stock 330's w / Q-Jets. Port engine was coughing, sputtering, backfiring at anything close to 4000 RPM. I thought it felt like I was losing ignition, but after testing I was convinced that I had a fuel issue. So, I changed the fuel pump, water sep filter, in line filter, still the same results. At that point I was going to pull the carb and rebuild it. When I disconnected the fuel line at the carb, I found the filter in the carb was filthy and pretty well plugged. I replaced that filter instead of pulling the carb, and the engine ran fine, no more problems. Apparently, it was getting enough fuel through the plugged filter to run on the primaries, but not enough for the secondaries. Sure wish I'd have checked that first... my question for you is, while you have good fuel pressure, have you confirmed what kind of flow you have into the carb itself?
06-18-2014, 06:34 AM
#24
Baja, considering my earlier issues with the Lightnings, that is a valid question. Didn't pull a header because they are a b!tch to get on and off. However, oil remains totally clear, and I would think milkiness would be showing up by now if it was sucking back enough water to make it run that bad. Might revisit later if I rule out ignition.
Offshore, the Holley's don't have the little inlet filters like the Q-jets do. Had a friend looking down the throat of the carb while I was trying to get on plane, and he said it looked like a good, steady stream of fuel.
Offshore, the Holley's don't have the little inlet filters like the Q-jets do. Had a friend looking down the throat of the carb while I was trying to get on plane, and he said it looked like a good, steady stream of fuel.
06-18-2014, 06:39 AM
#25
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I'm thinking if the electric fuel pump is wired into the coil, you're losing voltage at the coil. I'd wire in a relay on the fuel pump, to eliminate voltage drop.
06-18-2014, 08:16 AM
#30
Charter Member
Last couple yrs I've had. 1 motor in my cruiser not up to par with other. Was not as responsive and lower RPMs as other. Mechanically it was perfect. A timing light showed it fine at idle, would go up with RPMs as should, but then timing immediately dropped off after a couple seconds when RPMs held up. Doing some troubleshooting last yr I found only getting 11.5 v to coil. Traced issue back to dash. The power wire from the 9 pin goes up to dash, key then back to coil. At the dash that wire supplied 12v for the nav lites and etc. by feeding the fuse block. From the fuse block, leads went off to the acc and also to ignition switch. All fused. Most all the fuses were fairly loose and the spade crimps where also poor. The fuses and wires were warm do to the loose connections at fuse block creating résistance. Ditched the cheap POS Baja fuse block and put in a Blue Seas block and redid all the wire connections. Surprising how much everything now works right. Gauges are all steady, volt gauge no longer drops with each accessory turned on and the motor runs like a champ with full voltage back to the motor. With the lower voltage it was screwing up the knock sensor thus keeping the timing retarded resulting in low power. 4 yrs ago that same motor tuliped a couple of valves and blew a head gasket. Looking back, I think the wire issue was the cause of the motor failure.
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Last edited by US1 Fountain; 06-18-2014 at 08:28 AM.
