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

[skullman]

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?

 

[Duke]

I have the 1406 Edelbrock on my 38 Chevy P.U. and it has been a great Carburetor. I will make a wild guess here and say your float level is too high possibly caused by the float being stuck from being bounced around in shipping. I would pull the top off and check it out. With it being new you shouldn't have a problem with the tank being a little higher the the Carb. It is good idea to have a shutoff valve on the tank also. Good Luck - Let us know what you find - it will help us all.

 

[crossingts]

hmmm i kinda have the same thing going on. it cranks maybe 30 sec then starts ans smoke alittle like to much fuel i have checked the plugs yet. this engine did the same thing with a different carb so i wasnt to concerned it always does start. will be nice to see what the others have to say about it

 

[putz]

It sounds like you are vaporlocking your fuel line when it gets hot are your fuel lines along way from heat sources?

 

[Brucer]

Just out of curiosity, are you guys engines grounded to the chassis?

 

[skullman]

My fuel lines run along the frame on the passenger side of the car away from any heat source. The steel line leaves the fuel pump and the runs up the front of the engine and up along the valve cover away from any heat. There is at least 1" clearance all around the line. As I understand it vapor locking would not only affect the starting but the running as well which is not my problem. When the car starts it runs flawless and strong . . . my only problem is the starting. Even when it fires up there is not smoke which indicates it's not flooded.

 

[skullman]

Oh, and yes the engine is grounded to the frame.

 

[Wild Mango]

This is where a fuel pressure gauge justifies its $25:00 price. Makes diagnosing things like this easy.
My nasty suspicious mind thinks you have an electrical problem. Even if you have a vapour lock type problem she should still fire up on the gas in the bowls.
Something somewhere is loose, low tension electrical connection wise, is where I would look first after making sure the fuel pressure is OK just to eliminate that as a possibility.
Oh, and make sure the tank vent is clear. If thats blocked/ish the pump will pull a vacuum on the tank and when you shut off the vacuum will pull the fuel out of the line(but not out of the bowls, see earlier comment) and short term the pump will not pull vapour against the residual vacuum.
Happy tinkering..................................

 

[Hotrod46]

What carb gasket are you using?

I don't know if they still do, but Edelbrock used to recommend a thick insulator gasket. I know they send a thin gasket with the carb, but they still said to use a thick one. This was to keep fuel from boiling in the bowls. The aluminum body of the carb sometimes allowed this to happen.

Also, Edelbrock says no more than 5-6 pounds of fuel pressure. Makes me wonder why they sell 7 pound fuel pumps.

I spoke with the Edelbrock rep at Knoxville and he said that insulator gaskets and pressure regulators solve most of the issues with these carbs.

Mike

 

[terrymac]

I'm running 2 500 cfm edelbrocks with progressive linkage and had both float and needle valve issues. Irregularly the needle valves in the primary carb would stick and the residual pressure in the line would bleed off and flood the engine. If I started it right up or shotly after I shut it off there didn't seem to be a problem other than a few puffs of black smoke. But if it sat a bit it would whirl some before catching. I took the top off and sprayed the needle valves with air intake cleaner and lowered the floats. The engine is running alot better and starting easier. I didn't have any float specs so I just dropped then about 1/16
worth a look Good luck
T

 

[RPM]

The engine has to have several things to run! Compression, Timing, Fuel, and Spark. Would it be safe to "ASSUME" that the Compression and Timing? They should stay the same from heat. Seems the problem gets worse with heat. Electronic things hate heat! So is the engine losing its spark when it gets hot? Take an extra plug and open the gap way up, to about 3/16. Next time it won't start pull a plug wire and stick in your test plug and be sure to ground the test plug to the engine. See if you have spark, a bright blue spark.

GOT SPARK. Lets look at the fuel. Put a fuel pressure gauge on it and see what it has. None of this bull about it squirts across the room stuff. We need some numbers. Should be about 6 PSI. OK got fuel pressure. Pull a plug and see if it is wet or is it dry. If it is wet the engine is flooded, if it is dry it is not getting and fuel. Take the air clener off and look down the carb. DO NOT CRANK THE ENGINE. It might back fire and burn you face. Work the throttle linkage. Do you see gas being squirted out from the accelerator pump? Take a flash light and open the throttle all the way up and look down into the intake is it all wet, with gas? If it is all wet the carb is probably boiling over when it sets and heat sooks. The float level is too high, or the fuel pressue is too high, the needle and seat are leaking. See why we need a reading on that fuel pressure.

My guess is the float is set wrong and when it sets the fuel boils out and is flooding the engine. Try holding the throttle wide open when trying to start it.

 

[Francis Blake]

I have been working on engines for 55 years and I agree exactly with Ron. hope you get her fixed...Francis

 

[skullman]

Thanks guys. A lot of good suggestions . . . some I've tried and some I haven't. I have checked the plugs several times and they are always dry. Looking down the carburetor there is no indication of dampness from gas. I will open the throttle up completely and check down in the intake. I look over all the suggestions and check what I can over the long weekend. However living in the boonies requires a lot of patience because nothing is ever in stock. So getting things like a pressure gauge will have to wait until after the holiday. Thanks again for the suggestions.

 

[Brucer]

Ive had a coil cause a problem similar to this before, believe it ir not, coil would get hot and wouldn't put out enough voltage... I thought it was carb issue, but the carb wasnt draining after I shut the vehicle off, floats we're fine, needle and seat were good,power valve ok. My stepdad walked by and asked if I checked the coil, had a stock coil I swapped in and problem was solved..
I never thought a coil would make a car act like that..
I've seen ungrounded engines do that also, that's why I asked..

 

[RPM]

I went back reread your original post. What engine is this? Can you swap out the Petronix stuff for an HEI?

 

[rooster57]

I would also check that the 12 volts to the to the distributor is constant and doesnt degrage with heat. Connect a DVM to the distributor and monitor the 12 volts as the engine warms. Then monitor the voltage as you try to restart. Anything below 10.5 volts is to low running.

 

[just for fun]

The fact that it does start seems to point away from electrical problems. Faced with your situation, I would run it to normal temp let it sit long enough to be in "no start" setting. remove one plug wire, put spare sparkplug on that wire and set spare plug on manifold. Got spark? YES! put heat insulator under carb. NO Replace "brainbox" in distrubter.

 

[bill4u6]

Run the engine till it gets hot eather in the shop or on the road park it and remove the air cleaner use a drop light and look down the the carb what you will be looking for is gas driping down inside of the carb if it is there is one of two things going on dirt in the seat or float level. what happens this gas pouring down into the engine takes awhile to everaporate and then the engine will start and run fine untill it is shut down and then it will do the same thing all over again.:sad:

 

[409T]

Level of fuel in the float bowl is too high.

 

[jmr122848]

i vote electical, just because I had a GTO that did the same thing. some dummy didn't get 12 volts to the coil on start and when it was hot it wouldn't start. ran good, started cold, would restart, but sit for 10 min and you might as well just wait and hour.