loss of power

[gv78ta]

ok i was on my way out to the speedway the other weekend for a car show and when i almost got there my car felt like it lost some power and it started sounding kinda bubbly. i have also noticed that i'm using about twice as much gas as normal since this happened and seeing as how 93 octane is now 2 dollars a gallon i really would like to fix this problem. this problem is not constant either it is a little bit intermittent but most of the time it does what i described above. if anyone has any insight on this please let me know. all info appreciated.

[68chevelle]

what car and engine? deatails please. like engine whats done to it and stuff like carb and ignition. that would probably help.

it almost sounds like your carb needs to be rebuilt. there could be something that is blocking the needle and seat or something causeing to to flud a little.maybe even your plug wires are arcing sometimes and not sometimes. you could wasily check to see if the plug wires are all fine cuz i have searched for problems for quite some time and then discoverd that it was just the plug wires causing it.

[gv78ta]

its a pontiac 400 motor and a carter 4bbl carb

[68chevelle]

is the carb new? did you let it sit for a long time? im still kinda thinking it could be the carb. or maybe a vacume leake somewhere or something.

[gv78ta]

no the carb is old, i just bought the car about 3 months ago and from what i can tell they let the car just sit around a lot and didn't drive it. i've got the carb rebuild kit and i should be doing that within the next week or so. if it is the carb would that cause the power to be intermitent and the bubbly sound also?

[68chevelle]

it could. i dont totaly know what you mean by bubbly sounds. but its posible. just rebuild it and find out. it shouldnt make anything worse, just make sure they float is adjusted corectly.

[gv78ta]

by the bubbly sound i mean when the car actually feels like it lost power then it sounds like it is underwater

[macktoschool]

Check into what 69chevelle said about a vacuum leak. If it's using a lot of gas, that could suggest ignition timing. I would check for a crack in the vacuum advance hose.

[gv78ta]

well i started the carb rebuild today, i should be done with it and back on the car by about 6 tonight. i'll let you know how it went. when i get the carb back on then i'll check the timing too.

[gv78ta]

well the carb is rebuilt and back on the car. that's the good news. the bad news is i still have the same problems. i was speaking with a friends dad and i noticed a new thing that if i'm turning left kinda fast so that the car leans pretty good then the engine smooths back out and runs good but as soon as the car goes back level or on right turns the engine looses power again and gets the kinda bubbly sound back. anyways my friends dad said that this sounds like i might be getting vapor lock in my fuel lines. the only way he knows of fixing this is to get about 4 wood clothes pins and put then on the fuel line. somehow this fixes the problem but if this is the problem then i would like to find a more attractive way of fixing it if at all possible.

[macktoschool]

Wow, I can't say I've heard that one before. I've always solved a vapor lock condition by either changing the gas cap (stopped venting) or re-located the fuel lines away from the engine (excessive heat around your fuel lines is a bad thing). It sounds to me though, that you have a fuel pickup problem. Either there is some crap floating around in your tank that is not making it through the pickup (common with cars that have sat around a lot),your fuel pump is shot and sucking air, or your gas gauge doesn't work and you're running out of gas . If I'm not mistaken, I beleive there is a "sock" type filter in the tank that's supposed to block most of this stuff, and it might be plugged. This is one of those start at the tank and move forward kind of solutions. I would either commit to doing that now, or be content with chasing this thing until your hair falls out. Good luck though, I know how frustrating these can be.

[gv78ta]

well i tried reseting the floats in the carburetor again today and i still have the problems so i'll try the relocating the fuel lines thing and see if that works. but i know its not that i'm running out of gas because i have this problem even when i have a full tank.

[macktoschool]

Good luck, but I still think there is a Sock filter in the tank you might want to look at.

[Murray B.]

Originally Posted by gv78ta

... sounding kinda bubbly.

Bubbly could be low octane fuel in a motor that needs high octane. Over the years the octane rating of fuel has dropped. The owners manual for my '74 Norton recommends USA 91 octane regular fuel. Today regular can be as low as 87 octane. Try some octane boost additive and see if the problem stops.

[gv78ta]

well guys i feel really dumb. turns out that somehow the spark plug wire for my #1 cylinder got cut and it was making connection when the car would lean. the dead cylinder explains the power loss and the bubbly sound.