Running Problem
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Mountain Pass
Joined: Aug 2000
Posts: 139
Likes: 1
From: Marshall TX
Running Problem
I have a '78 F150 Explorer with 400/C6 that a year ago I took off stock carb/intake and put on Edelbrock Performer Intake and Reman Edelbrock 1406.
It has run fair the past year with a few stumbles here and there taking off from a stop which I attributed to the Edelbrock's reputation for the stumble at take off, but the other day I started it and out of the blue it ran horribly and bogged down and died. I finally got it running and limped it home(I was about a half mile from home). I took the carb off and opened it up and floats, needle and seats and all seemed to be free and work fine. I put it back together but have the same problem. It will start and idle but when you give it gas it bogs down. If you let off it will idle but if you keep giving it gas it will die or it will bog and then rev up. If it dies it starts hard. I've checked for vacuum issues but don't see anything. I even replaced fuel pump and fuel filter but issue remains.
I haven't performed any work or anything to the truck to maybe have caused the problem. It just happened.
It has run fair the past year with a few stumbles here and there taking off from a stop which I attributed to the Edelbrock's reputation for the stumble at take off, but the other day I started it and out of the blue it ran horribly and bogged down and died. I finally got it running and limped it home(I was about a half mile from home). I took the carb off and opened it up and floats, needle and seats and all seemed to be free and work fine. I put it back together but have the same problem. It will start and idle but when you give it gas it bogs down. If you let off it will idle but if you keep giving it gas it will die or it will bog and then rev up. If it dies it starts hard. I've checked for vacuum issues but don't see anything. I even replaced fuel pump and fuel filter but issue remains.
I haven't performed any work or anything to the truck to maybe have caused the problem. It just happened.
Lead Driver
Joined: Mar 2004
Posts: 8,922
Likes: 152
It sounds like the squirters weren't ever working right and aren't working at all anymore. I'm not a fan of that style of carb but i'm sure someone on here knows a lot about them. I'd just buy a Holley and move on.
Thread Starter
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Mountain Pass
Joined: Aug 2000
Posts: 139
Likes: 1
From: Marshall TX
I had an Edelbrock on my '69 Super Bee that never worked right. I put it on a '78 F150 with 351 race crate motor and it worked fine. It stumbled all the time on my Bee... never did on the truck. I've heard more than one person say that they had one of the Edelbrock carb and it works fine on one motor and no matter what you do it never works right on another motor.
....Weird.....???
I was wondering if by chance it might be something other than the carb causing the issue.
....Weird.....???
I was wondering if by chance it might be something other than the carb causing the issue.
Postmaster
Joined: Mar 2011
Posts: 2,698
Likes: 7
From: Taxachusetts
What's your timing set at?
With your vacuum gauge hooked to manifold vacuum - what are you reading at idle?
(the 1406 has manifold vacuum on the right nipple, ported on the left as looked at it head on).
With the motor still idling, pull the vacuum advance line from the carb and plug the port - apply vaccum (suck on the line or use a "Mighty Vac") to the line - any change in idle?
Pull the distributor cap and rotor - check that the weights/cams can move freely.
With your vacuum gauge hooked to manifold vacuum - what are you reading at idle?
(the 1406 has manifold vacuum on the right nipple, ported on the left as looked at it head on).
With the motor still idling, pull the vacuum advance line from the carb and plug the port - apply vaccum (suck on the line or use a "Mighty Vac") to the line - any change in idle?
Pull the distributor cap and rotor - check that the weights/cams can move freely.
Thread Starter
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Mountain Pass
Joined: Aug 2000
Posts: 139
Likes: 1
From: Marshall TX
If I remember I set timing either at stock or a couple degrees advanced a while back. I don't have a vacuum gauge but will try this evening to see what the distributor is doing.
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
Are you running a fuel pressure regulator? most Eddy carbs require one to make them "happy".
How about adjusting the linkage on the accelerator pump for a bigger pump shot?
Are you sourcing ported or manifold vacuum for your vacuum advance? ported vacuum will give you a more responsive throttle just off-idle.
How about adjusting the linkage on the accelerator pump for a bigger pump shot?
Are you sourcing ported or manifold vacuum for your vacuum advance? ported vacuum will give you a more responsive throttle just off-idle.
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Senior User
Joined: Feb 2013
Posts: 266
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From: Idaho
You can check your spark plugs. But first check to see if the carb is actually pumping gas into the engine...turn your vehicle off and take your air cleaner off. Look down the carb and pump the accelerator. You should see two good streams of gas when you pump the accelerator. If that part is working good start looking at your ignition system. If its not your accelerator pump might be worn...then take a quick look at your spark plugs this will tell if its burning good or not.
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Thread Starter
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Mountain Pass
Joined: Aug 2000
Posts: 139
Likes: 1
From: Marshall TX
I don't have a vacuum gauge but with engine off I sucked on vacuum advance and it moves freely.
I will check pump shot this weekend.
It's weird... it ran fine for a year or more, then one day I started it and it's run bad since.
I will check pump shot this weekend.
It's weird... it ran fine for a year or more, then one day I started it and it's run bad since.
Senior User
Joined: Jul 2011
Posts: 151
Likes: 1
From: Nanaimo BC
When you get it idling look in the carb for any fuel drips off the boosters. When you shut it off watch for a small wisp of fuel vapour. Also listen for small crackling noises from inside the carb. Eddy carbs don't like more than 5.5 psi fuel pressure.
What you described sounds like slight flooding.
What you described sounds like slight flooding.
Thread Starter
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Mountain Pass
Joined: Aug 2000
Posts: 139
Likes: 1
From: Marshall TX
I hope its not a cracked head!!
It does seem like flooding.... when I can manage to get it to run(it won't idle) and shut it off I can put my finger in the barrels there is gas that gets on my finger. If it is flooding why would that happen overnight? The carb is only a year old...
It does seem like flooding.... when I can manage to get it to run(it won't idle) and shut it off I can put my finger in the barrels there is gas that gets on my finger. If it is flooding why would that happen overnight? The carb is only a year old...
Postmaster
Joined: Mar 2011
Posts: 2,698
Likes: 7
From: Taxachusetts
As mentioned before - Edelbrocks don't cotton to more than 5 - 5.5 psi fuel pressure. Have you a fuel pressure regulator? If not, the excess pressure could be forcing fuel past the float into the venturis.
Another thing to consider is that you have a 1406 - meant for economy, inherently lean. You adjust (richen) the mixture screws to get rid of the lean hesitation and then you have a too rich mixture causing a (quadra) bog.
Try this if you can - get the springs, metering rods and jets from a "stock" 1405 and put 'em in your 1406 and go from there. Edelbrock also has a tuning manual online - free.
Another thing to consider is that you have a 1406 - meant for economy, inherently lean. You adjust (richen) the mixture screws to get rid of the lean hesitation and then you have a too rich mixture causing a (quadra) bog.
Try this if you can - get the springs, metering rods and jets from a "stock" 1405 and put 'em in your 1406 and go from there. Edelbrock also has a tuning manual online - free.
Senior User
Joined: Jul 2011
Posts: 151
Likes: 1
From: Nanaimo BC
If you feel gas it's flooding. Likely got something in the needle/seat.
Start it up, turn up the idle to keep it running and tap on the carb where the fuel inlet is with the end of a screwdriver. Sometimes that will clean it out and reset the needle. Or if you have a rubber fuel line to the carb squeeze it off while it's running and let it go and you could flush out the needle that way. Worse comes to worse you'll need to pull the top off the carb to check it out.
Changing the jets, springs and rods from a 1405 will only produce a very lean 1406 that you'll need to richen up to get it running right again.
Idle mixture screws are for idle only. Adjusting them richer doesn't cause a bog. There's 2 circuits. Idle and power. One common cause of the bog in a eddy is the secondary air valve weight. It's too heavy and doesn't respond quick enough causing a bog.
Start it up, turn up the idle to keep it running and tap on the carb where the fuel inlet is with the end of a screwdriver. Sometimes that will clean it out and reset the needle. Or if you have a rubber fuel line to the carb squeeze it off while it's running and let it go and you could flush out the needle that way. Worse comes to worse you'll need to pull the top off the carb to check it out.
Changing the jets, springs and rods from a 1405 will only produce a very lean 1406 that you'll need to richen up to get it running right again.
Idle mixture screws are for idle only. Adjusting them richer doesn't cause a bog. There's 2 circuits. Idle and power. One common cause of the bog in a eddy is the secondary air valve weight. It's too heavy and doesn't respond quick enough causing a bog.
Thread Starter
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Mountain Pass
Joined: Aug 2000
Posts: 139
Likes: 1
From: Marshall TX
Update:
I put known good carb(Holley 600) and issue remained. I set timing mark on balancer with timing tab and looked at rotor and it was dead on.
Symptoms- still will barely run regardless of how much gas you give it and will eventually die... spits gas out of top of carb(slight backfire).
Is it possible it jumped timing a little...? Will that cause the above symptoms? It's the original motor... 216,000 miles(but doesn't burn oil yet!!!)
I put known good carb(Holley 600) and issue remained. I set timing mark on balancer with timing tab and looked at rotor and it was dead on.
Symptoms- still will barely run regardless of how much gas you give it and will eventually die... spits gas out of top of carb(slight backfire).
Is it possible it jumped timing a little...? Will that cause the above symptoms? It's the original motor... 216,000 miles(but doesn't burn oil yet!!!)