Car stumbles under load.
Thread Starter
Drifting
Joined: Jul 2006
Posts: 1,871
Likes: 6
From: Sault Ste. Marie Ontario
Car stumbles under load.
Hi Guys,
A little help if you would please. My car stumbles above 3000RPM. It sounds like the ignition is stuttering but I think it may be fuel starvation.
I have a 454 with an Edelbrock performer carb. The ignition is MSD with a 6000RPM chip.
I just changed the fuel pump inlet hose to a preformed "S" type thinking the old line may have been pinched. No change!
Is it possible the return line is pumping too much fuel back to the tank and starving the carb?
A little help if you would please. My car stumbles above 3000RPM. It sounds like the ignition is stuttering but I think it may be fuel starvation.
I have a 454 with an Edelbrock performer carb. The ignition is MSD with a 6000RPM chip.
I just changed the fuel pump inlet hose to a preformed "S" type thinking the old line may have been pinched. No change!
Is it possible the return line is pumping too much fuel back to the tank and starving the carb?
Burning Brakes
Joined: Aug 2005
Posts: 1,164
Likes: 1
From: Europe, France
Does the engine rev freely ( in neutral ) above 3000 RPM or not ? This could indicate if it is ignition or fuel related.
What kind of carb do you have ?
Vacuum secondaries or DP ?
Did you check fuel pressure and float levels ?
Do you have a fuel ( and possibly clogged ) filter ?
Does it stumble the same if you punch the throttle hard and if you do it progressively ?
What kind of distributor do you have ( points or electronic/magnetic pickup ) ?
What kind of carb do you have ?
Vacuum secondaries or DP ?
Did you check fuel pressure and float levels ?
Do you have a fuel ( and possibly clogged ) filter ?
Does it stumble the same if you punch the throttle hard and if you do it progressively ?
What kind of distributor do you have ( points or electronic/magnetic pickup ) ?
Burning Brakes
Joined: Jan 2006
Posts: 1,223
Likes: 174
From: Fort Wayne IN
I was finally able to confirm my fuel starvation problem by putting the car in neutral, reving it up and holding it until it started to stumble, then shutting it off immediately and pulling my bowl sight plugs. Sure enough the primary bowl was empty and I concluded that the fuel pump was not keeping up with the engine.
Thread Starter
Drifting
Joined: Jul 2006
Posts: 1,871
Likes: 6
From: Sault Ste. Marie Ontario
Thanks for the input guys. Everything is brand new so I'm going to start with measuring the fuel pump pressure and then move on to the carb.
This is the first Edelbrock carb I've owned so I'll have to study the manual and take it one step at a time.
This is the first Edelbrock carb I've owned so I'll have to study the manual and take it one step at a time.
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