I was hopeing one of you might have an idea of what this could be. My car runs fine around town but just recently I started haveing problems on the highway. Its usually when I go to pass and I really romp on it, it just falls on its face and if you feather the throttle it will backfire and every once in a while catch and surge for a second then die out again but as soon as you stop it calms down and runs fine. Any ideas? Fuel delivery maybe?

Thanks for any help.

I say Fuel problem. check/change your filter, maybe about time to rebuilt the carb if it hasnt been done recently.

Ditto on the fuel filter....my SBC 350 recently had the same issues. After changing out a $.80 paper filter, the problem went away. Check the easy stuff first! Good luck.

I had something similar happen to my '74 Camaro when I still had it on the street. The sock on the fuel pickup had clogged and collapsed, and was sometimes blocking the flow of fuel almost completely. Then it would shift, and it would run fine for a while.

Sounds like a fuel problem of one sort or another.

I had similar issues caused by a loose needle seat inside the carb. It would idle and drive slow, but put any load on it and it would run out of fuel. The loose seat severely limited the fuel flow into the float bowl. It wasn't fun when it started...while in the passing lane at 70mph in traffic.

Check your float level and the filters; the inline filter if you have one and don't forget the sintered metal filters where the fuel lines screw into the carb bowls.

Tom

Hope you find the problem. Could be several things, as described here.

Fuel Filter....

happened to me many years ago, everything was brand spanking new.

Turned out the sock in the fuel tank sending unit was sucking up rust from the tank and plugging it up.

Ok so I changed the inline filter and no change but next week when I can afford it I'm going to get a carb rebuild kit I deffinetly think its a fuel issue originally a week before it really started giving me problems it was running a little crappy on the highway so I put dry gas through it and ran it hard on the highway and it seemed ok but this is allot worse before it would stumble and if you tromped on it it was ok but now it just totally craps out and no it isn't fun at all. I'm gonna pull the carb and see what I can see but I've never rebuilt one before so wish me luck and thanks for all the replies. Also for the sock issue I would have to drop the tank and replace it right?

Just take the sending unit out shouldnt have to drop it if its accessible uinder the car. The rings just tap them some counterclockwise a bit, the rest comes right out. Careful with the rubber seal and pulling the unit out not to damage it.

I would say check the fuel pump. if sounds like its losing fuel pressure. We had one start to crap out on the way back from a vacation. started running like crap at 75, but would run okay at 70, by the time we got home, it was running at 55. next day it finally quit. jim

Well I think I found the issue I pulled the carb and did my first tear down it was actually kinda fun. It was pretty nasty in there all kinds of crap. My carb is an edelbrock and it has one fuel line going in and two metal screens one where it goes in and another further down the line the second one was all gunked up and had a piece of stuff that looked like electrical tape on it I'm guessing this is the issue along with the rest of the crap in the carb. I will find out when I put it back on I suppose. My question now is do I just spray it with carb cleaner or is there a better way to clean it can I boil it in water or is it gonna cause problems I have it all torn down except for the bottom half that includes the bowls and butterflies.

Ryan,

You can buy GUNK carb cleaning solution in a bucket that comes with a wire basket. Simply put all metal parts into the basket, ease it down into the bucket and let it soak. Should be able to find it at any decent auto parts store.

Yup, sounds good.


Dont boil it in water whatever you do.

Ryan,

You can buy GUNK carb cleaning solution in a bucket that comes with a wire basket. Simply put all metal parts into the basket, ease it down into the bucket and let it soak. Should be able to find it at any decent auto parts store.

That is good stuff but whatever you do, do NOT get that stuff on your skin. Rubber gloves are certainly a good idea. Also be sure to replace the lid tightly when you are not using it.

Backfiring......sounds like jumped time to me. Had a GTO Judge with the same symptoms and it had two broken teeth off of the crankshaft gear.

Could be the mechanical advance mechanism frozen in the distributor. I had the same problem in a 350-4V Monte. The mechanism was corroded and the distributor wouldn't advance the timing at all. the vacuum pot would make it run fine at idle and cruising @ high vacuum conditions but wouldn't get out of its own way on freeway and sucked gas like a Hemi w/ both carbs wide open.

Well I rebuilt the carb and it came out good started first try but it is still haveing the same problems. I am quite iritated this morning since I'm not really sure where to go from here and I don't have much money to replace parts. I pulled the distributor cap and the terminals and button don't look the best but I'm not sure if that could cause the problem. also I checked my vacume advance and it moves freely and the hose is In good shape. Thanks again and anymore help is much appreciated.

Catylitic converter is clogged, lol, maybe you have an exaust restriction somewhere. One of the converters on my 85 Fullsize Blazer fell apart and was clogged just on the one side, had a similiar issue to yours. Yes I know you don't have cats, lol.

hey, sorry i didnt get back right away i lost internet for a bit. so i rebuilt and installed the carb same issue. before i put the carb back on i blew threw the supply hose and found no restriction at all. so i said screw it and baught a holley because i need the car on the road since my backup died. thing runs better than ever now. i think something is wrong with the edelbrock but im not sure what yet and i havent taken the right class at school to know. so at some point i will mess withit but for now all is well ish. look for my other posts for current issues.

It sounds to me like your running out of fuel at high RPM as well. I would advise getting your hands on a fuel pressure guage to see where the pressure is at.