• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Engine will not idle and is very choppy

EccentricMagpies

Well-Known Member
Local time
12:56 PM
Joined
Apr 19, 2011
Messages
313
Reaction score
36
Location
Wisconsin
74, 360 with a quick fuel carb...

Motor is in the car and has been Dyno'd. Number of hours? Not sure what amount of time these run at. I have the specs if those help?

I just replaced the fuel tank, sender and fuel line all the way to the carb.
On my first attempt to start the car it almost instantly started and actually ran at a slow idle. Felt satisfied I heard enough i finished some other things and replaced the fuel line from filter to carb with a chrome braided hose, mainly because i noticed a small leak on the flare connection I had and decided to just swap out with a hose.
Ran it again for maybe a minute, sounded fine.
Next I needed to fill the transmission with oil while running in neutral. Now it seems to run choppy, it starts hard (basically need to floor the petal to get it to fire and I cannot simply let go of the gas or will die)

Someone suggested that debris in the port would possibly be the issue.
When I cut the braided hose the one thing was trying to avoid getting any shavings inside and I ran fuel through the line prior to installing. But i'm wondering if this could be my issue? Just seems to make sense. (or wishful thinking that it's not something worse)

would this involve disassembling the carb or is the port removable from the body?
 
Recheck fuel lines first make they only have soft bends not sharp ones. Or use a five gallon gas tank and run a hose from the carb to the five gallon tank. If the engine runs then you know you have fuel delivery problem. If it doesn't run look in the carb open it up and make sure you have gas going into it.
 
Where's the fuel in the sight glass on the fuel bowls? I'd check your needle and seat on the carb and clean with carb cleaner while they are out. I bet something got stuck in there with all the changes.

I flush and blow out the lines before installation to make sure they are clean.

Edit: If not vacuum leak as posted above...easier to check first!
 
Carb Contamination is fairly likely.
That said I had similar symptoms with a bad amplifier (ignition module) and also when the shaft bushing in my distributor got dry and bound up.
You could check both of these pretty easily by pulling the distributor key in run and do a spark check with a spare plug.
Spark should be blue and crisp.
Note rotor and distributor orientation before doing anything.
 
if you have to hold it to floor to start I would say it is flooding, need to clean needle and seat imo.
 
Thank you all for the tips on this symptom I was having.

I originally thought it might be my solenoid but it was memorial weekend and the local auto part store wasn't even open and then I ended having to order it in.
I just put the new solenoid in and it fired right up and sat at the idle it once had.

I did notice that the wire to carburetor was unhooked on top of it.
It would be nice to take the car for a short drive but that can't happen yet. I will be careful to pay attention since I still do feel something could be in that carb with everything new going on.
Thanks,
 
How about a picture of that 'unhooked' wire going to the top of your carburetor?
 
Aren't all the QF carbs equipped with a strainer on the fuel feed inlets on the fuel bowls?
 
I am curious as to which solenoid fixes having to hold it to the floor starting and a choppy idle.
 
Auto Transport Service
Back
Top