I've been working on my car for about 6 months now (72 302) trying to get the body in shape. we had the car started a few times throughout the 6 month period and it seemed fine then. now when I start the car it's smoking pretty bad and wouldn't hold an idle. the sound from the engine didn't sound smooth when reving either, and it smelled like it was really flooded. thinking it was flooded we revved the engine for a while and kept it running at a high rpm but it still wouldn't idle. we didn't do anything to the engine except change the oil. we replaced the vaccuum advance line as it was looking old and cracked. I'm sure we put in on the correct place on the carb, the nozzle on the front near the top. it's a Holley 4 bbl. the nozzle on the bottom near the front I believe was blocked off before and it's plug came off so i replugged it up and it didn't help. when the engine was running there was a gas vapor that looked like steam coming out of the bottom nozzle before I replugged it. I took the air cleaner off and there is that same vapor that looks like steam coming out of the primaries, and there is gas trickling into the secondaries. I don't know anything about carbs so any help would be really appreciated. one more thing, when I changed the oil i put 5 quarts in, I don't think that should have been too much for a 302? if anyone has any ideas or a vacuum diagram for that it'd be very helpful nick
since you say the car sits and it sounds like you rarely start the car i say the neddle and seat is stuck... try putting a new one in. or tap with a small hammer to see if that will losen it up... however i would just put a new ones in. but then again it could be something else too... but i'd change that anyways!
Also could be as simple as stale gas. I read that gasoline has a 90 day shelf life now. Syphon out the old gas and add fresh, could save you a lot of work and frustration. If that is not it, then you have 1 step of trouble shooting done. I personally have had gas go stale over 1 winter. Depending on your climate ( and it is mostly a humidty factor) you could have stale gas and all of the symptons you described match that. Dan
is there an easy way to siphon out the gas with sucking it through a hose? my carb is pretty new, probably about a year and a half and the car has been started a few times and was actually driven about three months ago and was fine. the gas has been in the tank for about 6 months though total. the tank is actually almost completely empty, pass E, so maybe I could just fill it up without siphoning out the old?
Carb problem You have stated that the tank is almost empty, this leads me to believe that you have gotten some trash from the tank into the fuel bowls and is maybe holding the float needle open. Maybe some H2o in there too. Have you removed the float level sight plugs in the bowls to see if the fuel is level with the bottom of the hole? Car must be level and both bowls full of fuel, did the carb ever backfire when trying to start it, possible power valve blown out too. Without knowing your carb number etc. it is a shot in the dark, these carbs do have an external float adjustment on top of the bowl or bowls. See if you can get a good Holly tune up book and follow the procedure in them. Not to hard to fix these carbs once you have the idea whats inside and what things do. Most rebuild kits at the parts store's come with a diagram and can be confusing with the different models they fit, hang in there it will turn out ok if you take time and learn as you go. Good luck as always.
B-12 to the rescue? I've always been told that a can of B-12 chemtool in a tank of gas can only help things.....especially if the car sits more than runs. Or after the car has been sitting....just what I was givin' for free....
I use Stabil for gas that sits a while. Up north we have vehicle that sit for 6 months quite often. I would first pull the plugs and clean/read 'em. They may be fouled. I would slso get a rebuild kit, replace the power valve and needle and seat and gaskets. Look at the bowl while you are in there and check for crud in the fuel. That would be a start.....
I bought a haynes on how to work on holley's. I went through it and now it runs better than it ever has. like a new car thanks for all the help, I feel like I have a much better understanding of carbs. thanks again nick
