Well I have been working on an intermittent power loss/ engine miss for the last few weeks. What I was experiencing was a power loss when I got the truck up to speed and let off the gas a little. I would feel a loss of power then power would come right back. Found the dist. cap in poor condition and appeared to have spider web cracks so I replaced the cap and rotor, plugs and plug wires. No change. Next I replaced the fuel filter. The one that is near the fuel pump. No change. So still thinking it is a fuel issue I put a whole can of Seafoam Fuel Treatment in. Well as of right now she is running better. Here is one thing I noticed. Lately, while running bad, when filling up the tank I noticed a big whoosh when I removed the fuel tank cap. Like the fuel tank was under pressure, not vacuum. I have added fuel twice since it has been running better and no whoosh when I remove the fuel tank cap. Still not sure if it was the fuel cap malfunction or something like a fuel return line???? I do believe the Seafoam cleaned something out. Will run one more whole can per fill up to make sure things are cleaned out. I just hope too much Seafoam doesn't hurt anything but my wallet.
Seafoam shouldnt hurt anything. Ive been using it for a couple of yrs. now and have either had no results or positive results. Nothing ever bad.. Sometimes a carb. is so gunked up you have no choice but to remove it, clean it, and rebuild it. Following the directions is always a good ideal, however I have disconnected the fuel line at the tank and sucked it directly into the carb. let it sit for 30 min. or hour a number of times with no ill effect. I use it in everything, boat, chain saws, mini trucks, motorcycles ect. As for the pressure I would fine the return line to fuel tank (disconnecting at both ends if it has one) and blow through it.
Sea foam seems to be great but I took the fuel line off at the tank and stuck it into a can of Seafoam and it wiped out the fuel pump.It was a universal pump from Autozone and I have no clue as to what happened but it sucked about 1/4 can then just stopped pumping,it still ran but wouldn't pump.I really like the product and this is the only negative experience I've had.
fuel pump you have to change the fuel pump to an OEM. The fuel pumps run about 3 lbs of pressure but yours is kicking out about 7 and the carb. cannot get the excess fuel back to the tank fast enough ... just loading it up. my thoughts, dan
vacuum leaks are 85% of carb and idling problems, use a vacuum gauge or carb cleaner, carb cleaner will send the engine to high idle if you have a vacuum leak, make sure the vacuum port in the air cleaner canister is working properly, also check that your vacuum advance hose isn’t cracked coming off the distributor to the vacuum manifold tree. The vacuum manifold tree is brass on the bottom to go in to the block and plastic on top. Plastic wears out with time and will break or leak, which causes a vacuum leak. Some manifold vacuum trees are 3 or 4 port, make sure to replace it with a new one. When I buy parts I buy 3 at a time that way I have them on hand or in case they can’t get them any more. The vacuum manifold tree is located behind the carb. If you looking at the carb from the right side of the bed, it will be to your 1 O’clock tucked down inside. Remember to use a marker or different colored tape to mark the vacuum lines so you know where everything goes back too! Good luck!’
