Ok..I have this 454 in my 76 442...I just bought this car about a month ago...While driving. ?.if I floor it...power drops off when pedal is on the floor...if I slightly ease into it...no problems.....any ideas?....im thinking weak fuel pump...too small of fuel line...or fuel splashing rto the back of the carb maybe? ??....any help would be great.

 

Could be weak fuel pump, could be a fuel filter especially if high-speed performance is affected. Could also be carb pump or secondary problems. We can help more if we know what type carb you have. A QuadraJet by design will rarely fuel starve the secondaries unless fuel level is too low. A Holley with a bad power valve or secondary vacuum diaphram will do this type thing.

Olds used 3/8" fuel lines on their V8's so unless this car started life as a six-cylinder, doubtful the fuel line is too small.

Could also be tied to spark advance. if vacuum drops off too far on hard acceleration and the vacuum advance diaphram is iffy, spark can retard and drop power.

 

I would make sure your tune is maximized, I have a 454/ T400 with an Hei and 3:08 gears in mine, can shred tires with it.

 

My bet, carb rebuild time. You're not draning the carb by giving one stab on the gas pedal.
What kind of carb is it? Are the secondaries opening? Is the accelerator pump spraying gas?

 

Secondaries opening too fast
Any links missing or maladjusted on the carb?

Vacuum break is supposed to also slowly release the upper secondary air valve upon WOT in order to get the proper transition to full 4-bbl... assuming QJet here. Easy to ck the VB unit to verify it is working and holds vacuum.

 

The carb...believe it or not...says Carter AFB performance series right on the front. I look at it and it says...Edelbrock...but must be before Edelbrock took over. Anyway.. bought an Edelbrock accelerator pump , and will try that first.

 

Ok another question...I have since noticed that the previous owner has evidently bottomed out the car once or twice and as a result...Flattened the two bottom header tubes. So I'm having trouble finding engine swap headers for it, so since this is an A body car, will any A body car header fit??? It has headers now, so one would think a 454 A body header should fit. Right??

 

Yes, treat it like the Chevy version of your Cutlass.

 

will do. Thanks...been trying to put shocks on this thing....lord what a pain in the a$$!!!...got the front ones one, but the back ones...those two bolts way up top...HA!!!.... that's been fun, my buddy has a lift...so that's where its going next.

 

Those upper bolts are a bear, hope you have long arms.

 

well when it rains it pours. couldn't get the car started, did all the typical checks, carb was bone dry. so I throw a new fuel pump on it, still cant get fuel, cant get anything to come out of the tank. Soooo...looks like ill be dropping the tank, and since its out might as well throw a new sending unit and fuel hoses on it, new screen on the sending unit I hope solves the problem. Tried blowing air both ways, nope...notta. gonna do a couple more checks before the tank is out. Gonna try to suck fuel through the line, see if I can get some fuel, and run a long hose from the fuel pump to a gas can, make sure that ok, I put on a holly pump and had to change the clocking to get the hoses to fit, so I hope I didn't screw that up, would like to drive this thing some day!!!

 

See if your blockage is in the tank or the fuel line by disconnecting the rubber hose at the tank and fuel pump, then blow some air through it.

 

The tiniest leak in any of the rubber or steel lines between tank and pump and you will get mainly air instead of fuel. Replace all the rubber. Inspect the metal for wet spots, chafing, etc. Dropping the tank and redoing the sender/ sock can't hurt.

 

Ok....an update. Changed the fuel pump..AGAIN, ended up putting on an actual 454 pump, fuel was coming up from the tank, I think the pump arm was too short. I thought they would be the same thing as a small block chevy, this is not the case! Today had a few hours on my friends lift, and changed out the sending unit, hoses from the tank and the starter. Tightened up the tranny pan bolts, and changed out the shocks in the rear( much easier with the gas tank out!).
SO...the problem now is I have a miss in the right bank, and the third cylinder, has new plugs and wires, ill double check both again tommorow, but its a dead cylinder, just hoping its something simple, but havent been that lucky so far. Anyway that where im at as of now.

 

ok here are some pictures of the beast

 

Make sure your wires and plugs are good and seated properly, it's not unheard for parts to be bad out of the box.

 

So i posted this on another thread, but i seemed to have hurt the engine some...opps. When i get on it hard, a small amount of blue smoke puffs out, so i dont know if a have a bad valve seal or a broken ring, but with the amount the previous owner spent on this engine i dont want to totally screw it up, sooo....im gonna pull it and do a refresh on the motor, and hope like hell i didnt scar a cylinder. so while thats being done, ill throw in a 350 i have so i can keep driving it, may save a little on gas as well!!

 

Well glad to hear your still at it, hopefully nothing serious. Before you pull it, why not do a thorough compression and leak down test. Valve guide seals can be changed simply without pulling the heads and are very inexpensive. You can do a lot of troubleshooting while the engine is in the car and not have to take it apart.

 

i may do that, but thinking im gonna put a different cam in it and may as well just refresh the whole engine anyway. I really want to know what compression ratio im running because i dont think its what the previous owner has told me, shoot i'm not even convinced it's a 454 at this point!

 

Post some pictures of it.