Carburetors Carb discussion and questions. Upgrading your Third Gen's carburetor, swapping TBI to carburetor, or TPI to carburetor? Need LG4 or H.O. info? Post it here.

cold start requires pumping gas pedal?

Thread Tools
 
Search this Thread
 
Old 04-23-2011, 12:47 PM
  #1  
Junior Member
Thread Starter
 
Handmedown86's Avatar
 
Join Date: Apr 2011
Posts: 1
Likes: 0
Received 0 Likes on 0 Posts
cold start requires pumping gas pedal?

Hey guys,
I just joined this board today to hopefully get some answers. Father-n-law sold me an 86 Z28 w/305 carb for $500. for a cold start, i have to pat the gas pedal about 30+ times to get it running. After that it starts right up fine. Seems its loosing vacuum? Thanks ahead of time for the help.
Old 04-23-2011, 03:10 PM
  #2  
Supreme Member
iTrader: (1)
 
EvilCartman's Avatar
 
Join Date: Apr 2000
Location: Northern CA.
Posts: 5,321
Likes: 0
Received 4 Likes on 4 Posts
Car: '82 Z28
Engine: 350
Transmission: TH400 4,000 stall
Axle/Gears: Currie 9", 4.56 gears
Re: cold start requires pumping gas pedal?

Should only take one or two pumps at most. If you haven't tried starting it today, go out there, take the air filter housing off, pull back the choke blade so you can have a look down the small primary boosters of the carb. Work the throttle and see if any gas is shooting out, if there was, go ahead and try to start it without pumping the gas any more. If nothing is coming out then the gas is draining back out of the carb or the gas is just evaporating out of the fuel bowl.
Old 04-23-2011, 11:27 PM
  #3  
Member
 
DoubleV's Avatar
 
Join Date: Jun 2009
Posts: 218
Likes: 0
Received 0 Likes on 0 Posts
Re: cold start requires pumping gas pedal?

Is the choke setting? In other words, does the flapper above the primaries snap shut when you fist pump the gas? If it doesn't, that's most likely your problem along with the possibility of what EvilCartman says about the gas leaking out of the carb overnight ( leaky well plugs ).
Old 04-23-2011, 11:54 PM
  #4  
Supreme Member
 
built91Z28's Avatar
 
Join Date: Feb 2010
Location: Orlando
Posts: 1,446
Likes: 0
Received 2 Likes on 2 Posts
Car: 1991 Camaro Z28
Engine: 357, Canfield heads, solid roller,
Transmission: Upgraded 03 Cobra T56
Axle/Gears: 9" 3.50 gears and Detroit Locker
Re: cold start requires pumping gas pedal?

With the warmer weather here now, I doubt its anything to do with a choke. I have a Mighty Demon carb, theres not even a place to mount a choke, and even with my motor built like it is, 1 pump of the gas pedal and it fires right up. Does the same even if it gets into the 30's. The choke will let it run when cold without having to hold the gas down, but shouldnt stop it from firing up.
Old 04-24-2011, 05:13 PM
  #5  
Supreme Member
iTrader: (1)
 
EvilCartman's Avatar
 
Join Date: Apr 2000
Location: Northern CA.
Posts: 5,321
Likes: 0
Received 4 Likes on 4 Posts
Car: '82 Z28
Engine: 350
Transmission: TH400 4,000 stall
Axle/Gears: Currie 9", 4.56 gears
Re: cold start requires pumping gas pedal?

I've found that q-jets need a choke even when warmer weather is around, or at least the one on my other car does. Like yours, my race Demon will start up in cold weather without much trouble.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
jklein337
Tech / General Engine
2
09-19-2018 06:23 PM
Wade787b
TPI
2
09-29-2015 01:15 PM
johanlindgren
Interior
2
08-16-2015 12:16 AM
355tpipickup
Tech / General Engine
3
08-13-2015 07:35 AM
drathaar907
TPI
0
08-06-2015 04:20 PM



Quick Reply: cold start requires pumping gas pedal?



All times are GMT -5. The time now is 08:33 AM.