View Full Version : My carb keeps coughing..
12-31-2002, 08:52:00 AM
I have a Holley 4160 (list 1850-4) 600cfm carb w/electric choke.. These past couple of weeks that it's been pretty cold in the morning, the car has been pretty tough to get started.. I usually turn the key & crank once to get some fuel & oil flow, then pump once on the gas & crank again.. It'll usually start then shut off on me after 15-20 seconds..then when i try and start it again, sometimes the carb will flood and cough up some fuel. My air filter is shot b/c of this. I also noticied that there is no fuel filter. Unless it is internal on the carb, but i dont think so...so I know that i have to add one, but what else could be a problem that is causing the flooding and "coughing up" of the gas? What i usually have to do to get it started is take off the air cleaner, stick a screwdriver in the "flap" to keep it open, then it'll start, but roughly until it warms up.. (10 minutes min. b4 I can drive it so she dont stall)....
12-31-2002, 05:23:00 PM
4spd Z28's owned '68,'71,'77new,'78new,'80new,70 still,daily driver 87 G/N.
Home Page on 1970 Z28
Chevy's Baddest Toys
12-31-2002, 11:45:00 PM
First thing is I would pump the pedal before you crank over the engine. Second where is the choke setting at (black round cap on carb) and does the fast idle work when you start the car (does the car idle above 1200 rpm when cold). It sounds like you might have the choke too rich causing it too flood or the fast idle is set too low or not working. Thats why I said to pump the pedal before cranking as that is what sets the cam for the fast idle.
70 camaro 350 th350
74 trans am 400 th400
01-01-2003, 11:50:00 AM
Well, as for the choke, I dont really know how to check what setting the choke is at..but..I took off the black cover, sprayed some carb cleaner everywhere, and also noticed the positive wire was loose. So i fixed it & so far so good..but the weather got warm so i'll just have to wait n see..
As for the fast idle, I dont think it's working b/c it doesnt idle that high... It'll idle at above 1,000rpm, then after a minute, i'll give it gas an it'll drop to about 700 or so.. then it'll either warm up or stall...
also got another prob..When i drive and come to a stop in gear, the accelerator linkage(or throttle linkage) sticks a little causing the car to idle high(1,000 - or higher rpm)..but it i stick my foot under the gas pedal n push it up, she goes to where she should be.. I tried changing the return spring to a heavier one, but then it's too heavy.. no happy medium..but i dont think the problem is the spring, something's up with the linkage... any ideas??
Considering either rebuilding or just buying an edelbrock performer 600 w/elec. choke..
01-01-2003, 11:18:00 PM
Holly Carbs run very well when Clean.
The electric Chokes on Hollys are good, but
the choke plates stick a lot. Make sure
you Gummout the linkages and that the little
plastic cams on the passenger side of the
carb are free to move with the choke plate.
Hollys run like crap when dirty... and it
don't take much dirt to get a Holly to
It sounds to me like you need to clean and
adjust your carb. One place to start are the idle air passeges on top of the
Venturies. They are little tiny pressed-in
brass plugs that clog up really really
easily and will cause all sorts of trouble.
After cleaning, I'd adjust the choke. I
THINK that the Holly Electric choke covers
have a little pin in them that pull the
bimetalic spring that operates the fast idle
cam and choke plate. Make sure that pin
engages the bimetalic spring.
As to the 'Fuel Filter'... there is one
internal to the carb (Pull off the fuel
line and then the big bronze nut). Many
times it's removed because someone said they
don't work well and clog.
As for replacing the carb (If it comes to
that) Edelbrock makes fine Intake Manifolds
and should stick to what they're good at.
I have no doubt that you can get this
carb to work fine if you put some cleaner
and care into the equation.
Just my humble opinion.
'78 LT Type.
350 CID - Nothing Stock
Stil needs Slicks,
and a Headliner...
01-02-2003, 06:37:00 PM
Hey, thanks alot Will for the advice.. The other day i took off the plastic cover on the choke and sprayed some carb cleaner in there,as for that little pin you mentioned, would that be the piece that is on the plastic cover? If so, i did make sure it was engaged. But i'll check it again...And I also have to check out that fuel filter.. How do you actually make an adjustment on the choke though? It gave me trouble again this morning.. The only way she starts in the cold is by me having to stick a screwdriver in the "butterfly" to keep the choke open.. it's frustrating, but i know it's something stupid that I'm just missing..
Well, thanks again..
01-02-2003, 10:03:00 PM
You might have more than one problem, and you might be inducing more problems trying to fix the first. If you are getting backfire through the carb, that means that you are getting fire into the intake manifold. Your carb cannot do this. For this I would look at valves and ignition. This could also cause hard starting, causing you to crucify your carburetor. Before you nail the carb to a cross, make sure your ignition system is working properly (look at the plugs and check timing) and your valves are working (do a compression test and if necessary pull the valve covers and watch the valve train operate). My money says you will find a problem and start a new positive relationship with your Holley. I say this because I just went through it. Good luck.
74LT 350/4spd Midnight blue metallic w/black interior
01-02-2003, 11:46:00 PM
a rebuild or a new carb,,,,,evidently there's trash in the carb as well..I've told folks before,,AFTER a rebuild,,fuel filter,,fuel filter,,fuel filter....
and they still want to blame a clean carb,,that was...
01-02-2003, 11:50:00 PM
p/s,,,,396 in my chevelle wouldn't even think of running before 170 degress,,,,180-90 usually..no choke,,,but it would still crank in 30 degrees with a 1/4 shot...