carbed 350 surging/loss of power under load
 

I have a carbed 350 and I just did a full tune up on it but the car had this issue when I got it. Idles fine with no problem. when you pick up the rpms and get on the throttle to pick up speeds from say 30-40 up to highway speeds the car surges and looses power almost as if it is staving for fuel.....any ideas? I appreciate any help.

Re: carbed 350 surging/loss of power under load
 

You probably listed your own problem. Fuel. If it feels like it's starving it likely is. I had a similar issue. I could rev in the garage all day. I could drive around town pretty well as long as I didn't lay into it at every stop. Hell, one day I got on the highway and was able to do 65-75+, but had an old lady in front of me on the ramp, so I got up to that speed VERY SLOWLY.

Anywho, my on-carb fuel filter was full of rust dust after maybe 20 miles. Tank looked like it was full of coffee. I'm still putting it back together, but I'm pretty sure that was my issue. Between the sock in the tank being completely plugged and the fuel filter not doing so well either. Spark and air were good soo....

Re: carbed 350 surging/loss of power under load
 

I just changed all my fuel filters but true in the tank I have no idea. trying to get this car on it's feet has been a trip.

Re: carbed 350 surging/loss of power under load
 

Now you did say carb, but are you running a block mounted fuel pump or an in-tank?

Re: carbed 350 surging/loss of power under load
 

Re: carbed 350 surging/loss of power under load
 

edelbrock 1406....msd distributor....in-tank with regulator.

Re: carbed 350 surging/loss of power under load
 

I have a stupid question.....this kid I got the car from had this regulator on here....it was a factory 305 tbi car....now I know the in tank tpi pumps make WAY to much pressure for a carb but he chose to still use the tbi original pump did he need the return line hooked up to the regulator?

Re: carbed 350 surging/loss of power under load
 

The return should be used. Also what regulator? Do you know what pressure range it's good for and where its set?
does the car load up when it sits idling?

Are you sure it's not breaking up? Where is the timing set, what's the max advance?

Re: carbed 350 surging/loss of power under load
 

I took advice from DevX83z and changed the fuel filters and just drove her like 6 miles and.....nothing, didn't do it so I think it is safe to say that it was fuel delivery. I already bought a rebuild kit for that edelbrock 1406 so I will be cleaning that carb up. I honestly have no idea what regulator that kid put in the car. I know this has nothing to do with this but, I have a passenger oem seat and tbi ECU for free if someone wants them.

Re: carbed 350 surging/loss of power under load
 

Cut the filter open when you took it out? Just to see how bad it might have been? I ask because if you changed the filters once recently and now again, it's not really solved just bandaged.

Re: carbed 350 surging/loss of power under load
 

First off, save your fuel pump by replacing the regulator with a return-style regulator. A non-return style regulator will allow pressure to build up behind the regulator and make your pump work hard.

Another problem that you "may" be encountering is the fact that in a blocking-style (non-return) regulator, your fuel is sitting in the fuel line until it is ready to be pumped into the carb. With modern gas (think ethanol content) fuel can start to boil at about 100 degrees. If you have headers, your under-hood temps can easily reach this temperature. A return-style regulator will feed unused fuel back to the tank where it can be cooled down, and feed your carb with freshly cooled fuel more consistently. Vapor lock and fuel starvation problems can occur when you pump bubbles into the float bowl.

Since your're running the Carter AFB/Edelbrock 1406 I'll assume for the moment that you don't have excessively "skinny" secondary metering rods.

There are a whole host of other problems, like timing, centrifugal advance, and probably more that I can't think of at the moment that can have the same effect. But I'd start fixing your fuel system first.

Re: carbed 350 surging/loss of power under load
 

True. I will add, IF YOU ARE ABLE TO DO SO, plumb the return style regulator into the RETURN line. This way the fuel is unrestricted from the pump to the carb, and restricted in the return line back to the tank. Easier to do with a Holley carb, not as easy with your Carter AFB/Edelbrock 1406.