PowerAddict
Chief Petty Officer
- Joined
- Aug 8, 2007
- Messages
- 418
Hey guys, I'll try and explain the situation as best as possible. It is a 1994 454 with a thunderbolt 4 ignition and a weber 4 barrel.
I got the boat and it hasn't ran since last year. Put some heet and stabil in the gas tank (about a 1/3 full) and filled the tank. Put a new battery in it, new starter, oil change, impeller, and bam, she's up and running again. Carb was spitting fuel out just fine and everything seemed to work great. took the boat out and it ran great for about an hour and a half. The first hour or so was mainly idle with a little increased throttle a few times. Then we got out on the lake and opened her up and she ran awesome! Then, all of a sudden, we heard this awful popping and shaking from the engine so we got off the throttle and tried to see what the issue was.
We could never re-create the popping because it wouldn't go over ~3300 RPM's now and acted like it was running on about 4 cylinders. There was a little water coming up through the breather tube into the carb. It still was shooting fuel out the carb, would start right up every time, and would idle and go up to about 1800 RPM's before it really sounds like its killing itself. THere is no water in the oil, and it has sat for 2 days and there is STILL no water in the oil.
I'm fairly certain it is intake gaskets, so I went ahead and changed them. I made sure all the pushrods were tight to ensure I didn't lose a valve, or lost some lifters, everything was great.
I haven't run it yet, but I thought I'd get some input here just in case. Is it possible it could be the ignition module on the distributor, with my experience with hall effect or optical sensors, they either work or they don't? I did not change the fuel filter, could it be as simple as that being clogged even though the carb looked to be shooting plenty of fuel? Any input or suggestions would be helpful.
Thanks guys!
I got the boat and it hasn't ran since last year. Put some heet and stabil in the gas tank (about a 1/3 full) and filled the tank. Put a new battery in it, new starter, oil change, impeller, and bam, she's up and running again. Carb was spitting fuel out just fine and everything seemed to work great. took the boat out and it ran great for about an hour and a half. The first hour or so was mainly idle with a little increased throttle a few times. Then we got out on the lake and opened her up and she ran awesome! Then, all of a sudden, we heard this awful popping and shaking from the engine so we got off the throttle and tried to see what the issue was.
We could never re-create the popping because it wouldn't go over ~3300 RPM's now and acted like it was running on about 4 cylinders. There was a little water coming up through the breather tube into the carb. It still was shooting fuel out the carb, would start right up every time, and would idle and go up to about 1800 RPM's before it really sounds like its killing itself. THere is no water in the oil, and it has sat for 2 days and there is STILL no water in the oil.
I'm fairly certain it is intake gaskets, so I went ahead and changed them. I made sure all the pushrods were tight to ensure I didn't lose a valve, or lost some lifters, everything was great.
I haven't run it yet, but I thought I'd get some input here just in case. Is it possible it could be the ignition module on the distributor, with my experience with hall effect or optical sensors, they either work or they don't? I did not change the fuel filter, could it be as simple as that being clogged even though the carb looked to be shooting plenty of fuel? Any input or suggestions would be helpful.
Thanks guys!
