Can you help me . . . Edelbrock can't!

[skullman]

All your ideas are helping me rule out things that might have been a problem. I have ruled out electrical as a problem. The floats are correct but I lowered the just a tad. The fuel pump was a 5.7 to 8 lbs pump so I put a regulator on and the engine is running great at 4 lbs . . . however it didn't help the problem. I can't get a heat insulating gasket until Wednesday (remember I live in the boonies and it was a holiday weekend to boot) so I'll change that on Wednesday. I took the car out on a 20 mile run today and checked the plugs when I got back. They signs of dry fouling which indicates an overly rich mixture or too cold a plug. My first thought was to fine tune to get a little less rich air mixture when I discovered a problem with the carburetor which may or may not be contributing. The idle screw on one side of the carburetor appeared to be tuned to the engine, but in trying to fine tune the carburetor after the drive I have discovered that it only makes a very slight difference in the running of the car. I can screw it all the way in and the car barely stumbles at all and I can take it completely out of the carburetor and the car again just barely stumbles until I put my finger over the hole then the car runs good again. I've tried cleaning and blowing this out but nothing changes. I'm not sure what this indicates but I'll keep you posted as I continue to mark things off of the list. Thanks again for all the suggestions.

 

[bill4u6]

Edelbrock uses step up springs on there meatering rods now if you are pulling low vac you can put weaker springs in. what happens is a long duration cam and low vac will let the rods lift and alowe excess fuel in at idle and this makes adjusting your idle jets impossable

 

[Rick]

Vapor lock is a terrible thing.I think you need the insulator plus reroute your gas line away from the headers or manifold.The reason i say this is it runs like raped ape till you shut it down.At this point the heat from the engine starts to boil the gas somewhat and you get vapor lock.When the engine cools down the vapor goes away.Just my old butt talking from expierience.I had a Henry J that did the same thing but just my opinion.

 

[Rick]

Read this and tell me i'm wrong.
Vapor lock - Wikipedia, the free encyclopedia

 

[Hotrod46]

Just a little suggestion on the insulator gasket. You don't have to get the one that Edelbrock sells. It's too expensive IMO. I've always been able to find them cheaper at a good parts store. Sorry, I can't give you a specific application to ask for. If they'll let you look through their gaskets, you can usually find one. Get one that's divided or has four holes. I've used both types and can't tell much difference. Don't get an open one as that may cause mixture or distribution problems.

You'll need longer carb studs with the thicker gasket too.

You also might need to pull the metering rods and step-up pistons and check to see if the one on the side that is not responding is moving freely. It might be stuck in the up position. Getting the metering rods back in the jets as they should be can sometimes be a little tricky too. The rod on that side may be out of place.

I agree with bill4u6. Put a vacuum guage on it if you have access to one. Low or wandering vacuum can cause rich mixtures if you don't run lighter step-up springs.

Mike

 

[skullman]

More good ideas. The Edelbrock owners manual says the springs might need to be changed to set the idle if the vacuum reading is 8 or below. My gauge shows the vacuum to be 13-15. I'll see about getting a set of weaker springs tomorrow. I also checked and metering rods and springs on both sides are in place and moving freely. As for the gasket I have been through the entire collection of gaskets at both local parts houses and nothing like a thick heat insulator gasket for this application. But I'm thinking this might be a lot of the problem. I just tried to start the bucket and the hard start has kicked in again so I immediately pulled the carbureter and no only was the gasket wet (some of which could be from pulling the fuel line) but so was both sides of the intake. I'll know once I get a gasket installed. If nothing else I'm getting a real education at what can go wrong and what to check. I'll update again once I get a gasket and a set of weaker springs. Thanks again for all the ideas.

 

[Brucer]

For the insulator gasket, you might consider a 1inch phenolic spacer...jegs or summit sells them,make sure you get longer studs..

I'm not real familiar with edelbrock carbs, what does the accelerator pump arm look like? I know on a holley you need a few thousandths play in the pump arm if not at idle the pump arm will contact the pump and can cause a drip and cause a flooding situation..

 

[tnoftsger]

Just a thought, is you fuel tank vented? If not, the pressure inside the tank and lines can go WAAAAY up due to expansion of the fuel and vapors. This increased pressure can overwhelm your needle and seat and push gas in the motor until the pressure returns to something the needle and seat can handle.

If you have a pressure guage, watch it for 15 min. after you shut it off and see it the pressure climbs.

 

[skullman]

Just wanted to update everyone who offered suggestions for this problem. I tried almost every suggestion made here and after doing that and literally doing everything that Edelbrock recommended the problem didn't go away. Finally in frustration I returned the new carburetor as faulty, literally bolted on a another new carb and have been running with a smile on my face every since. C'est la vie! It has been a learning experience and I just want to say thank you to everyone who offered a suggestion(s).

 

[rooster57]

Those damn Eldebrock "Kuhneutson valves" are a pain in the neck. Here is a great place to get parts for it.
Kuhneutson Valve - $65.99 : KaleCoAuto, Hard to find automotive items!

 

[putz]

Nice to hear that it is running smooth. Put some miles on her.

 

[Screaming Metal]

Hi guys. My bucket is finished and have it on the street, but I'm having some carburetor issues that are taking the fun out of driving it. The car will fire up and run like a bat out of h - - - first thing in the morning and will run and start all day long as long as I don't let it set for more than 10-15 minutes. It I start the car within 10-15 minutes it will fire immediately and run great . . . but if it sets for 30-45 minutes I have to crank and crank and crank before it will start. Pumping the gas pedal or not makes no difference. Once it becomes hard to start it will continues to be hard to start until it is completely cools . . . like overnight. Also after you have cranked and cranked to get it started it runs like a champ again and the whole process repeats itself. I have talked with Edlebrock's tech guy several times and he can't seem to help me. The engine is a fresh 350 with brand new Edelbrock 1406 carb on Edelbrock Performer RPM manifold. Everything is new . . . mechanical fuel pump (with pressure rating of 5.7-8 lbs), spark plugs, wires, Pertronix Ignitor and Pertronix coil, fuel filter, steel fuel lines, wiring and 14" x 4" air filter. Is there anyone out that who has experienced this problem and can help a frustrated old hot rodder enjoy his ride?

Edelbrock is a good product........only talk to the tech's the salesmen don't know anything.............unless you talk to Vic himself or his daughter.......

 

[skullman]

It's summer here in Oregon and this is my everyday ride for the summer . . . rain or shine . . . except for the days I doing something new to it. I bought and rebuilt it to enjoy and that's what I intend to do. I talked with a couple of tech guys at Edelbrock. and as with most tech-ie types there are good ones and bad ones. The first guy I got was pretty much no help at all, but the second tech guy was able to help. Quite honestly the guys on the forum helped as much as anyone. Cudos to hot rodders and their experience . . .