Edelbrock carb problems

Scott,

In an earlier response you mentioned that you did not replace the needles and seats. Do it. If they are hanging up, and it sounds like they are by your description of what's happening when you hold the top upside down.

We run two Carters on a Nostalgia Super Stock Plymouth. If the needle and seat gets to be an issue, all other carb tuning will not seem to matter. It's one of the first things to make sure you have correct before messing with any jetting or metering rod changes. One thing you can do to check to see if the floats are "flooding" the motor is to run the car without the air cleaner on it. Get the engine up to speed, and then let it idle. When it cuts out, or if it will continue to run, look at the top of the carb to see if it is wet. If it is, it's a dead give-away that the floats aren't correct. If you set them correctly with the top off, and the carb's still wet, the problem is likely in your needle and seat. There are two per carb. I believe that there are two sizes for AFB style as well. The part number for the ones we use in our 750's (same as 650) is: 25-861. I hope it helps.

 

Your problem is that you have an Edelbrock carburetor.

 

Scott did you ever figure it out?

 

....and a fire extinguisher.

 

Umm, not turning over isn't a carb problem. Is it seizing up temporarily till it cools off and can turn over again?

 

The best thing I ever did with a Holley carburetor is tape a dollar bill to it and throw it in the lake,,the damned thing loaded up and caught my 40 sedan on fire,,I hate them! HRP

 

This turn over thing must mean different things to different people also won't crank. To some it means won't start To me it's the starter won't turn the engine or the motor is stuck.

 

To me it sounds like flooded cyl.s If the float is wrong and dumping fuel in to the manifold it will get a hydro lock and not turn over untill the fuel leaves. Most of the time in goes straight to the pan and contaminates the oil( pull the dip stick and smell for fuel).

 

cool thread...take a Carter over a Holley any day.....

 

While I am a Holley guy ( or was anyways) rebuild or build-um from scratch, its what I am used to from drag racing, BUT Recently I rebuilt my Edlebrock, leaning it out as much as I safely could.

The float high and low level are equally important. I think 7/16 high and 15/16 low......

In closing, it is a very simple carb, and my engine runs the best it ever has right now. So I like the Edlebrock just as much now that I have had one apart....

 

Exactly what happened to us on a NEW 2-4 setup with the street fuel pump, which supposedly did not require a regulator because they were all tested to put out less than x lbs. pressure. I got this thing running sweet, then, all of a sudden, it would fill the top of the intake manifold with gas. Scarey shit. The Rear carb would waterfall, filling cylinders and that was everything new and floats adjusted 5+ times. Fuel pressure regulator solved the waterfall, but these carbs are OVERLY sensitive to fuel pressure. 5.5 lbs MAY be TOO much. Try lower.

How about some more input on the needle hook location on float. Please be specific about where it should be.

 

It's in the link rfraze. Needle hook do's and dont's.
http://www.crankshaftcoalition.com/...hester_Quadrajet_4MV_carburetor#Trouble_spots

 

Sounds to me like you might have a major vacuum leak. Are you sure of your carb to mainifold fit, and that you have the right gasket under it. Make sure there are not any vacuum outlets on the carb that don't have a plug on them or a line that has slipped off. Might also be pumping way to much fuel in and locking a cylinder when it won't retry.

 

Funny how some things work for some people and don't for others. I run an unregulated stock fuel pump to feed two 600cfm Carters and never had a problem in the last 5 years with this setup.

 

Happened to a buddy. I found he had the Fuel supply & PVC connection switched at the carb. Qjets have the fuel supply in front where the PVC connection is on the Edelbrok

 

HELLO... You keep linking Quadrajet info to an AFB thread..

 

I just did mine and it did the same thing. The problem I had was that I set the floats incorrect. I listened to U tube instead of reading the instructions. Once the floats were exactly set the way the instructions said it worked right.

 

HELLO!!!
It's cause rfraze asked about it dude!
And maybe you should read the whole thread. The op swapped back to his quadrajet and parked the eddy a long time back.
DUH!!

 

I am thinking that if we had used a stock fuel pump, instead of the "street", this is the one you need, pressure-tested Edelbrock pump we bought, we might not have needed a pressure regulator. I see an Edelbrock carb and I think pressure regulator, but this was supposedly a "matched set". Our "tested" pump showed 10 pounds of pressure on the regulator gauge I then installed. The waterfall situation stopped at about 5.5 lbs.

At ease on the needle hook question! I did ask, because there are some very smart or experienced people on here and someone previously mentioned a trick.

 

I had a similiar problem on a dual quad set up I built many years ago.Had a matched pair of AFB's and a stock pump that put out 6 lbs pressure. After many trys adjusting the floats and different needle/seats I installed a regulator. Had to run it at 3 lbs to stop the flooding.
So I experimented with different size fuel supply lines. Found the cure by going larger on the lines feeding the carbs. 1/2 inch as compared to the 3/8 originally used. THe bigger lines provided a bigger pressure drop after the reg and I was able to increase fuel pressure to 5 lbs.
THat might explain why one set up runs great at 6 lbs and another set up needs a reg to control the pressure.

 

Thanks for the tip, NUTS. I did build 3/8 hardlines for this one and will keep that in mind.