Technical Edelbrock Carb issues

Hey everyone,

Haven't really been on the board in a while. Still have the 38 panel, and I was wondering if anyone else had been experiencing issues with edelbrock? The engine is a 351 windsor bored and stroked to a 408. Carb is an edelbrock 1411 750 cfm. This is the third one I've had. Replaced the first one in 2017, which appeared to work properly for awhile, but developed an issue with not keeping idle and the engine was just loosing power. Replaced that one last year and now I've got the same issue developing. Was driving fine, when like a switch the engine lost it's idle set and kept wanting to stall. Had to rotate the throttle screw three full turns to get the idle somewhat stable, but I've again lost power. Anyone else had this issue? Thought is might be a manifold leak, but when I tried misting around the seals there was no change in the engine idle.

I'm going to call Edelbrock this week as well. Will post whatever I find out. Thanks in advance for any advice!

Regards,
Christopher

 

Having the same issues on new AVS 500 CFM on a 350

 

how much fuel pressure do you have hitting the inlet ? i had an eddy acting the same way and i had too much pressure so it was kind of flooding itself out . if i recall 4-5 lbs is about the max for input pressure. another possibility is its getting hot and percolating the fuel .

 

Yep. Fuel pressure is critical with these carbs. Find out what your fuel pressure is before you do anything else. Edelbrock will ask you the same question. It may not be a carburetor problem at all. Ideally, you want about 6psi fuel pressure with that carb.

 

Hey guys,

I have a fuel pressure gauge in the engine compartment just a short distance from the carb and it is reading around 6 psi. Which is what it has always read since I had the truck. So I don't think it is that.

I don't run the truck very often. Really just start it up once a month to keep things working and then a short spin around town every so often when the weather is good. Was running great last summer when the carb was brand new. and I maybe have 100 miles on it since then, probably less.

 

I have coined the term "edelbrock sludge". I use these carburetors on about everything i build because i buy them cheap at swap meets, and can walk into o'Reilly's and buy a rebuild kit off the shelf. But my experience is that ever so often you gotta pull the top and clean the fuel bowls. With the main jet's being located on the floor of the fuel bowls, there's no way that they aren't susceptible to trash. And idle issues are sometimes corrected with a good "burping" of the carb to suck that crap on through. Rev that baby up to around 3k and choke it out with a rag. Then clear it out. Fuel pressure and float level are important on them as well. Hope you get it figured out man

 

6 lbs a bit high

 

Check the accelerator pump shaft. They are made of plastic,and take a curve over time.When it gets bad enough the carb acts like you say....no idle,and you have to run the rpm up to keep it going.Run the engine,and put pressure on the top of the shaft where the linkage fits.If it smooths out as you press on it ,and take out any curve you need a new one.

 

I have Edelbrock carbs that get crapped up in the fuel bowls from E10 gasoline.......no issues with straight gasoline. Seems their aluminum is susceptible to exfoliation/corrosion from the alcohol in E10.

 

I have changed to a holly. No more edelbricks. That is what I think of them.

 

If you've got a fuel pressure regulator, cut the pressure back a pound or two. Fuel volume is more important than fuel pressure. Look down into the throttle bores and see if there's fuel dripping from the main nozzles and puddling on the throttle plates when the idle goes wonky.

You might also try disconnecting the fuel pump and temporarily hooking up a small gravity feed fuel tank. A gas tank off of an old lawn mower or similar works well for this. You just need enough gas to keep the float bowl filled for a short time. Fire it up and see if it starts idling normally again.

 

I have also found this to be true, particularly with cars that aren't driven often. Non ethanol fuel does help but locally is only avaiable in a few stations and then at a high price plus only 90 octane.
Best solution I have found if you need the extra octane is premium 10% plus Sta-bil 360* additive.

 

A few pictures to give some indication. I think the fuel pressure is well within what Edelbrock suggests.

 

Nothing but Holley for me. Never had any luck with Edelbrock carbs along with my brother and friends who are running them. Had a new one on my 302 in my 51' lasted a year, went back to Holley!

 

Thanks- LLOYD'S PAINT & GLASS, "And idle issues are sometimes corrected with a good "burping" of the carb to suck that crap on through. Rev that baby up to around 3k and choke it out with a rag. " (I'm a long time AFB fan )
I've seen this done with the choke flap also

 

Never had a problem with an Edelbrock carb. Always keep pressure at 4 1/2 to 5 psi. One one my 53 F100 is 15 years old. Latest one on another rod works great at that pressure.

 

I always dump a bottle of Gumout or Lucas nitro cleaner in every full tank to keep the bugs out. Also burn Shell 93 Nitro+ only. Lloyd's spot on about the sediment and the jets. Need to crank it up every now and then for a 30 minute trip at operating temp to blow the carbon off the pistons, too. Kill two birds.

Joe

 

Sounds you are driving around on old gas to me. You have never run a full tank of fresh fuel out of it.

 

If your not racing, and that may not matter, look at the 750 Summit if your going to buy new again. Too many favorable reviews too ignore. Seems funny but I’m running on 2 WCFB carbs that were manufactured in 1953 and been no trouble for me in 6 years. Manufacturing, sealants, coating, etc of the past may have just been better even tho toxic I guess….

 

Could be, but I always run it down to less than a quarter before I refill and I always run premium. Carb cleaner may be worth a shot.

 

. .Today’s gas is seasonal blended for the temperature. Most gas looses the light around 45 days so this contributes to the problem when they sit. Does the same thing in lawnmowers. The ethanol in today’s gas deteriorates and degrades the rubber parts in the fuel system. The less gas you have in the tank the more of a condensation problem, the moisture makes the alcohol separate from the gas also. You can check the gas by putting it in a 10 ml graduated test tube put in 5 ml of gas and add 1ml of water and let it sit and it will separate and you can see the water between the gas and alcohol and figure your %.

 

Another vote to knock the pressure down to 4.5

 

Thanks everyone for the insight!

Edelbrock is recommending I check and adjust the floats. So I guess that it my upcoming weekend project. Wish me luck. I'll also pick up some gumout cleaner while I'm at it. I'll be back to report if it works.

 

I've had that issue several times with mine. Same carb for 25 years. Have to throw it in neutral, to keep revs up, to get it home. Junk in the idle/air bleeds. First time, just removed mixture screws, and give it a little blast of carb cleaner, and compressed air. Next time, I sprayed carb cleaner down the bleed openings, in either side of the primary opening/choke plates. Don't have a diagram handy, but if I find one I'll attach it.
Bottom line, like @Lloyd's paint & glass , mentioned above, junk in the circuit.

 

Thanks! I was reading another thread where someone said it was blocked air bleeds, which they blew out by removing the idle screws and spraying carb cleaner down until the cleaner came up the bleeds. Slightly annoying, but if that is all I need to do to re-establish normal operation, not the worst outcome.

 

There are 2 square float bowl vent holes on the top of the carb, near the plates that hold the main jet needles. Pour in a good dose of Marvel MO in these holes when the vehicle sits for any period of time. Keeps the crappy corn juiced laced fuel from drying out in the float bowls and leaving that nasty white powdery residue.

 

They don't like heat, 1 inch phenolic spacer works well.

 

Three carburetors, same symptoms? What ignition are you running?

"Was driving fine, when like a switch the engine lost it's idle set and kept wanting to stall."
^^^ This gets me right here. "Like A Switch"

I'm not saying it is the ignition but it is a possibility. What is the common denominator? Going through three carburetors, that's a clue.
I would go through the tune up procedures and makes sure that the engine is in time and what ever ignition you have is in spec. One warning....When a distributor is worn, it can have a wandering zero.
Meaning....you set it this week, everything is cool.
A month later...."Was driving fine, when like a switch the engine lost it's idle set and kept wanting to stall.".....

Another thing to look at is fuel pressure....
Dirty gas tank...
Ballast for ignition....faulty?....lack there of?.....has one and does not need it for what ignition system you have?...
Switch?
Connections?
Coil?
Grounds?

I would build the carburetor and go through the tune up stuff paying close attention to the electrical system.

 

Look for a Carter Competition series kit it and go I don't like the knock offs.

 

I kept thinking it was an ignition issue when the second carb developed idle the issues. Checked everything in and out, and kept checking off and on for a year because the carb was very new so figured it must be something else causing all of the idle problems. Found nothing. Timing was good and everything was working properly. Wires were all good. It's all pretty much MSD ignition. Pulled the carb, replaced it again and everything worked great, at least for about a year. Still always worth checking again.