Help! Firebird 400 problems

Hi, my name is George Crawford. I own an 81 firebird formula that i recently dropped a rebuilt 79 pontiac 400 in. It ran fine for awhile then i put an edelbrock performer intake and 750 edelbrock carb on it.
It ran great for a couple months then the weather cooled down and it has run like shit. When i try to start it it overloads on fuel and floods and when i do get it going it runs real ruff and dies if i don't turn the fast idle way up to keep it idling. I checked the floats for sticking and they seem to be fine. (The carb and intake are brand new with only about 100 miles on them.) I installed an in-line fuel filter because i thought that might be the problem but it still won't run right and the air filter isn't clogged. I even backed off the idle screws to make it run leaner and it didn't help. Besides the intake and carb everything else is stock. Please let me know if you have any solutions...I can't figure it out.
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"George" . I own an 81 firebird formula that i

thats alot of carb for a stock engine. if i were you i'd drop to a 500 -550 cfm carb. usually anything over that is just wasting fuel on a stock engine. fuel doesn't vaporize as easy at lower temps. and those intakes are cheap for a reason. get a victor jr.
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First off, IIRC a Victor Jr is a SBC intake, won't fit on a Pontiac 400.
Second, a Performer intake flows the same or worse than a stock intake. They are cast from the same dimensions as a stock intake. The only thing you gain is a bit of reduced weight (but maybe a bit more for a late model EGR restrictoid intake.).
Third - the 79 400s came with 800 cfm quadrajets as fars as I can tell. A 500-550 will choke the crap out of a 220 hp 400.
Fourth - Quit buying those Edelbrock AFBs, waste of money. They can be made to run well but it takes more work than tuning a quadrajet or a Holley. If you know how to make the air cleaner pan fit, run a 750 Holley DP (4779 IIRC). A cheaper route is a good poncho (7074262) Qjet or an early Buick Qjet.
Cold weather and carb problems sounds like a choke problem to me. Is the carb fitted with an electric choke? Is the choke opening all the way? It's the first thing I would check with what you outlined above.
Dave(running an 800 Holley DP on the 355 with no problems)
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Throw out the aftermarket carburetor---useless. Why buy something poorly modeled off the original when the original does just fine? :)
Put the stock 17059263 Q-jet on there and tweak it from stock a little bit. It will run 10 times better, get better fuel mileage and perform better.
There's no reason to deviate from a Q-jet on most applications, especially a 1979 stock 400. As noted, it's putting out 220 HP, nothing outrageous. Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
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says...

I'll second that. I don't think any of the 4bbl Pontiac 400-455 came with anything smaller than a 750 cfm. A 500 cfm would choke the living $#%T out of a 400! S.I.N.N must be thinking about Chebbie garbage.
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Also assuming we are talking about a Pontiac 400 there is no such thing as big and small block in Pontiac.
Same basic thing from the 265 vin S all the way up to the 455 vin W.
Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
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snipped-for-privacy@uiuc.edu (George) wrote in message

Well i solved the problem...Anyone interested in the solution, it turned out to be fouled plugs...I checked them previously, and i was getting some spark...i figured enough to make her run anyway...they were ac delcos...i picked up some bosch platinums and she runs like a top...i also took your advice and turned the idle screws to leaner...she's running great...not quite as snappy as i hoped still though..any advice on that i'd appreciate it..thanks for the help other wise... George owner of an 81 formula with a cherry 400 in it.
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