newbie tech question

[chevyconvert]

just drove my new car today (see "chevyconvert" under newbies)
1970 440/six pack/4-spd.
the car runs/drives/shifts fine. no misses.
When you start to really give her the gas she justs starts to die (bog?) until you let up on the gas and she smooths out. Same thing trying to accelerate up a steep hill.
I'm thinking electrical first. The ammeter is pegged to the "C". Loose connection maybe or bad alternator.
It's almost like it temporarily runs outta gas.
Any help appreciated.
Thanks

[4Cruizn]

My first thought is the carbs??  What do the plugs look like??  Maybe needs to be jetted??  Not sure but I know we'll get to the bottom of this!! 

[Oldschool]

Are you able to check the fuel pressure? You could be running out of gas. It has enough pressure at idle low rpm/load, but it's possible that when you load it up and extend the rpm's, the fuel pump can't keep up with the demand.  Did the previous owner have similar gremlins?.  Have patience---we'll get to the bottom of it.  BTW--great looking ride!...........Oldschool

[chevyconvert]

4cruzin:Haven't had a tool near her yet. no black smoke or soot in the tail pipe though. I realize lean would be even worse!
If it's running lean could it cause this?

oldschool: that's exactly what it feels like! the previous owner was a chevy guy...bought this car with a couple of others at the same time. never drove it!

[4Cruizn]

What size fuel lines are you running??  5/16 or 3/8 ?? 

[chevyconvert]

I just got the car today so a little unfamiliar with it.
I assume its the stainless steel (?) looking line under the passenger door next to 2 smaller brake (?) lines. haven't traced them further.
If so it's 3/8'' o.d. and was told all three are new (and they look it).

thanks

[4Cruizn]

How about the sending unit in the tank??  That would need to be upgraded as well.  Lean jets could cause it I would think . . . let see what Chryco has to say about it. 

[chevyconvert]

chryco?

[dodgetkboy78]

Almost sounds like one of the carbs isnt getting fuel..................................

[MEK-Dangerfield]

My guess is a fuel problem. Possibly a bad accelerator pump on the carb., or the secondaries are opening too soon or too late.

  Mike

[torredcuda]

A bog like you descibe is a temporary rich or lean condition in then carb assuming everyting else is OK.If it is just off idle I would guess either the accerlater pump is bad or you may need to do some tuning of the pump cam,squirters etc.If it is at a higher criusing rpm it is in the jetting or the timing of the secondarys opening.

[Super Blue 72]

I agree, my first guess would be the accelerator pump in the center carb.  (We are talking a 3x2bbl set up right?)

When's the last time the center carb was rebuilt?  If i'm guessing correctly, with the engine off, look down the venturi of the center carb and move the throttle rod.  In theory you should get a good shot of gas from the accelerator pump.  If not, it might be time to rebuild the center carb and go from there.  I'm not too familiar with the six pack set up but I think the outer carbs don't have accelerator pumps so you don't have to look there for accelerator pump issues.

I don't think that it's an electrical problem.  The ammeter pegged to the C is a separate problem from the ignition system.  You say there's no misses.  Electrical usually shows up as being very abrupt changes in the engine, rpms.  Fuel is more surge like and smoother than electrical problems.  My best guess.

[chevyconvert]

thanks for the input.didn't have much time tonite to look at it after work. The fuel line off the tank turns out to be 5/16'' o.d. though.
I'll try and followup on your suggestions a.s.a.p...
Thanks again