Carb issues... need help..

[Marck]

Hey guys..

I've been away for a while dealing with a lengthy bad personal situation, but I've finally gotten to a point where I want to start doing Marck-stuff again.. 

That means Charger-stuff..

Now, honestly I haven't driven my Charger for a couple of years, but I've kept it in the garage, and fired it up once in a while, and made sure the battery was kept charged, tyres inflated and so on.. The basics..

Before typing this I've changed out the gas, and tried spraying carb clean in the carb. (not sure if done correctly)

My issue is, that I can get it to idle fairly easy, but I have to feed in the gas s-l-o-w-l-y if I want to bring up the rpm, otherwise it stalls. It makes a "hissing" sound if I feed in the gas to quick. A quick dap of the throttle brings it almost to a stall, but it recovers almost everytime.

I'm thinking carb related..

Now, my general understanding of carbs is, that air and gas comes in, magic ensues and I get to light up my tires.. 
I've tried google and youtube, but with out some basic understanding of carbs I'm pretty much lost.. 

I'm adding pictures, and would appreciate any advice on which screw to adjust, or where to spray carb clean..

Thanks guys..

-Marck

[XH29N0G]

The hissing sound is probably diagnostic, but I don't know what that is (vacuum?).  I do know that sometimes after a car sits for an extended period of time that the accellerator pumps can fail.  Are the accellerator pumps sending in gas when the throttle is moved? 

[Marck]

The hissing sound is probably diagnostic, but I don't know what that is (vacuum?).  I do know that sometimes after a car sits for an extended period of time that the accellerator pumps can fail.  Are the accellerator pumps sending in gas when the throttle is moved?  

It can rev as high as I want to - but slowly in the low rpms, so I'm not thinking fuel starvation? Or am I missing something?

Thanks.. 

[XH29N0G]

The accellerator pumps put a shot of gas in when the butterflies initially open.  This keeps the engine from stumbling.  Once the flow of air through the venturies increase, gas is sucked through the boosters to allow the engine to run at high RPM and keep accellerating.  The symptom would be an engine that falls flat when the accellerator is depressed, but could work OK if the RPM are already high, so it might work OK from 3500 to 5000 rpm, but not for RPM lower than 2500-3000 RPM

[Marck]

The accellerator pumps put a shot of gas in when the butterflies initially open.  This keeps the engine from stumbling.  Once the flow of air through the venturies increase, gas is sucked through the boosters to allow the engine to run at high RPM and keep accellerating.  The symptom would be an engine that falls flat when the accellerator is depressed, but could work OK if the RPM are already high, so it might work OK from 3500 to 5000 rpm, but not for RPM lower than 2500-3000 RPM

Ok, that sounds a lot like my situation.. I'll have a look down the carb and see if it shoots in gas when I move the throttle linkage.. Thanks.. 

[Marck]

https://youtu.be/YQ-dcSmmigs

I'm not seeing any gas.. 
Can carb clean fix this?

[Just 6T9 CHGR]

More than likely the accelerator pump diaphragm has ruptured if you are not getting any stream of fuel....this is of course after you verified that the fuel bowls are indeed filling up and the float level is correct....

[Marck]

I think I've figured it out.. There seems to be a fuelpressure problem.. I'll begin takimg it apart tomorrow, and see where I'm loosing pressure..

[John_Kunkel]

Doubt if it's a "fuel pressure" problem, if there's enough fuel in the carb to run the car there's enough for the accelerator pump.

As stated earlier, either the pump diaphragm is ruptured (but this usually results in fuel dripping out the bottom of the pump) or there is a blockage in the pump circuit. Some Holleys have a discharge needle valve below the pump nozzles, in a car that has sat for some time the valve can become stuck preventing fuel from getting to the nozzles.

[XH29N0G]

https://youtu.be/YQ-dcSmmigs

I'm not seeing any gas..  
Can carb clean fix this?

As Just 6t9 and John said it is likely the diaphragms on the accelerator pumps.  Make sure gas was in the carb bowls when you do/did the test.  If the bowls were empty then there would not be any gas and you might get a false negative, but my guess is that there was enough gas and you just diagnosed your accelerator pumps.  

Provided it is the pump, you will need a new pump of the right size.  There are two different possible sizes.  My guess is you have 30 cc rather than 50 cc pumps.  I found a video online at https://www.youtube.com/watch?v=MaVmVplBeJo that shows how it is done.  You will need something like that found at the following page http://www.jegs.com/i/Quick+Fuel/793/35-1/10002/-1, but there are plenty of other places to get these.

If you have a fuel pressure problem, that is another issue altogether and will point to the fule pump or some other issue.  

As an aside, I see you are from Denmark. I should know more, but I only managed to learn two phrases (my daughter taught me when we lived in Odense).  "Det var Ikke mig" and "Jeg vil ya ikke" (I thought it sounded more like gil ya).  She was in kindergarten at the time.  We spent a year and a half visiting your country and had a wonderful time.  The phrases worked only a few times to get me out of trouble or keep me from responsibility  

Good luck with the carburetor and car.  I hope the accellerator pump is the fix.

[Marck]

Thanks for the input guys, I've read and re-read them all..

I took this video of my fuel pressure, so you guys could chime in on it..
https://youtu.be/OxAeZcC8QJE
Now, I could easily block the line with my finger and no gas came out, and the fuel pressure gauge I have in the car didn't even move when I turned on the pump.
I'm gonna work on the fuel pump first, since it needs doing anyway, and I hope it might fix my other issue..
I'm guessing that something got stuck in the intake on the fuel pump.. 

I'll report back what I come up with..

[Marck]

https://youtu.be/YQ-dcSmmigs

I'm not seeing any gas..  
Can carb clean fix this?

As Just 6t9 and John said it is likely the diaphragms on the accelerator pumps.  Make sure gas was in the carb bowls when you do/did the test.  If the bowls were empty then there would not be any gas and you might get a false negative, but my guess is that there was enough gas and you just diagnosed your accelerator pumps.  

Provided it is the pump, you will need a new pump of the right size.  There are two different possible sizes.  My guess is you have 30 cc rather than 50 cc pumps.  I found a video online at https://www.youtube.com/watch?v=MaVmVplBeJo that shows how it is done.  You will need something like that found at the following page http://www.jegs.com/i/Quick+Fuel/793/35-1/10002/-1, but there are plenty of other places to get these.

If you have a fuel pressure problem, that is another issue altogether and will point to the fule pump or some other issue.  

As an aside, I see you are from Denmark. I should know more, but I only managed to learn two phrases (my daughter taught me when we lived in Odense).  "Det var Ikke mig" and "Jeg vil ya ikke" (I thought it sounded more like gil ya).  She was in kindergarten at the time.  We spent a year and a half visiting your country and had a wonderful time.  The phrases worked only a few times to get me out of trouble or keep me from responsibility  

Good luck with the carburetor and car.  I hope the accellerator pump is the fix.

It's funny, but quite a few on this board have been in Denmark, either on vacation or for work..
You actually remember the best ones for getting of the hook.. 

[Just 6T9 CHGR]

Thanks for the input guys, I've read and re-read them all..

I took this video of my fuel pressure, so you guys could chime in on it..
https://youtu.be/OxAeZcC8QJE
Now, I could easily block the line with my finger and no gas came out, and the fuel pressure gauge I have in the car didn't even move when I turned on the pump.
I'm gonna work on the fuel pump first, since it needs doing anyway, and I hope it might fix my other issue..
I'm guessing that something got stuck in the intake on the fuel pump.. 

I'll report back what I come up with..

That is most definitely a problem

[XH29N0G]

I agree.  The fuel pump should pump fuel.

[69wannabe]

Anytime one sits for awhile say more than 6 months without getting started up and ran even a little bit the fuel goes bad these days and your fuel system will need some attention. I would get a new fuel pump from mancini racing. The carter street pump is a good choice and more than likely a holley brand carb kit to freshen up your carb with. As nice as that carb looks it really shouldn't be to bad to get cleaned up. Once you pull both bowls and metering block's you will need to spray cleaner through all the holes in the main body and in the metering blocks to make sure they are all open and clean. Also replace both your accelerator pumps since they may be stuck and not pumping any fuel down the throat of the carb. Amazon has many holley books that are easy to read and understand. Be sure to wear safety glasses when you are using carb spray since it will not do your eyes any good if it gets in either one of them. A new set of spark plugs may be good for it too since it's been sitting for awhile. Glad you are back to working on your charger!!!

[XH29N0G]

One quick question?  Have you taken a small funnel and filled the bowls with fuel (through the air vents) and then tried the accelerator pump test? 

[Marck]

One quick question?  Have you taken a small funnel and filled the bowls with fuel (through the air vents) and then tried the accelerator pump test? 

No, haven't had time to mess with it since my last post, but I might get to it tomorrow.. Just to clearify, the airvents are the two diagonally cut tubes on either end, right?

Thanks.. 

[Marck]

Anytime one sits for awhile say more than 6 months without getting started up and ran even a little bit the fuel goes bad these days and your fuel system will need some attention. I would get a new fuel pump from mancini racing. The carter street pump is a good choice and more than likely a holley brand carb kit to freshen up your carb with. As nice as that carb looks it really shouldn't be to bad to get cleaned up. Once you pull both bowls and metering block's you will need to spray cleaner through all the holes in the main body and in the metering blocks to make sure they are all open and clean. Also replace both your accelerator pumps since they may be stuck and not pumping any fuel down the throat of the carb. Amazon has many holley books that are easy to read and understand. Be sure to wear safety glasses when you are using carb spray since it will not do your eyes any good if it gets in either one of them. A new set of spark plugs may be good for it too since it's been sitting for awhile. Glad you are back to working on your charger!!!

Thanks, if I can't get the pump to work again I'll definately look in to Mancini..
Thanks for your tips about Amazon, will be looking into that right after I press "post".. 

[Marck]

I was just looking in to the different books about Holley carbs, but I can see that they cover different carbs.. Does anyone know, from the pictures, what version mine is?

[69wannabe]

Looks like you have a 4150 style double pumper on there. On the choke horn there is a list number that will be something like 4777 or 4779. the 77 is a 650 and the 79 is a 750. 

[Marck]

Looks like you have a 4150 style double pumper on there. On the choke horn there is a list number that will be something like 4777 or 4779. the 77 is a 650 and the 79 is a 750. 

It does actually say 4779-9, which males sense as I was told it had a 750 on it.. Thanks.. 

[XH29N0G]

One quick question?  Have you taken a small funnel and filled the bowls with fuel (through the air vents) and then tried the accelerator pump test? 

No, haven't had time to mess with it since my last post, but I might get to it tomorrow.. Just to clearify, the airvents are the two diagonally cut tubes on either end, right?

Thanks.. 

yes.  I do not know the best way to fill them.  I modified a funnem to make an insert that was even smaller than the are.

[Marck]

Sooo, fuel pump works just fine, just ran the inlet line straight to a gas can and it flowed like a champ all the way to the carb..
I'm now in the process of draining the tank, so I can drop it, and see what's what in there..  

[Marck]

So, here's what I learned today.. There's nothing wrong with the fuel pump, any of the lines or the tank..
It seems that the pickup in the tank can rotate, if I turn the hose on the outside, which has the ufortunate effect that the pickup in the tank finds it self above the gas level in the tank..
I pretty sure that when I put the tank back in, when I had gotten the trunk floor fixed, I connected the hose in such a way that the pickup was not on the bottom of the tank.. After having drained the tank to change the gas, I put just enough gas back in it, to make it run but not well.. Is my guess..

I guess the pickup is not supposed to be able to rotate, anybody tried this before?

[Marck]

So after a lot of messing around with the gas tank, fuel line and fuel pump, it has helped a bit, but the issue remains.
I've just ordered the pump diaphragm from Jegs. The sum of the parts came to just over 5 $, but with shipping and tax I'm ending up paying just under 50 $ for it.. 
Thanks for all your help..