New Fuel Pump??
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Joined: Dec 2004
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From: Raynham MA
New Fuel Pump??
My 76 sb 350 auto L82 is having trouble, now it doesn't start. I think it's the fuel pump. So I pulled it out and bought a new one at Autozone. Not sure if this was the right move.
Problem is:
1. It's too tall, don't think it will even fit. Should I be using a different one?
2. The arm that sticks out in the old one has a spring under it, the new one does not
3. There are only 2 outlets in the old FP, while the new one has 3?
4. I noticed I had 2 fuel lines coming up from the back of the car, the smaller diameter one is capped off. The larger one feeds the fuel pump. Why would this be?
Thanks for any advise..
Problem is:
1. It's too tall, don't think it will even fit. Should I be using a different one?
2. The arm that sticks out in the old one has a spring under it, the new one does not
3. There are only 2 outlets in the old FP, while the new one has 3?
4. I noticed I had 2 fuel lines coming up from the back of the car, the smaller diameter one is capped off. The larger one feeds the fuel pump. Why would this be?
Thanks for any advise..
Le Mans Master
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
AZ gave you a stock replacement.
The PO has eliminated the return line so you need a replacement 2 port pump.
Have AZ look up a fuel pump for an earlier year or plumb the return line back in.
The PO has eliminated the return line so you need a replacement 2 port pump.
Have AZ look up a fuel pump for an earlier year or plumb the return line back in.
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Joined: Dec 2004
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From: Raynham MA
I think it hangs down too low, not sure it will even fit. Also, the fuel lines are going in another direction. Not sure what issues i'm going to have with that.
Maybe I'm better off getting one exactly like what I have? Just need to figure out what it is. There is a # on it, s9009e28a. Not sure if this is a model #, etc.. Maybe it's a Holly FP? Trying to do some research online to see If I can identify what it is.
Maybe I'm better off getting one exactly like what I have? Just need to figure out what it is. There is a # on it, s9009e28a. Not sure if this is a model #, etc.. Maybe it's a Holly FP? Trying to do some research online to see If I can identify what it is.
Race Director
Joined: Jul 2001
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The new pump looks like the correct one. The one you removed is definitely not the correct one and it seems that Bubba has previously visited your car with his usual downgrades.
I would get the correct fittings to go with the correct pump and be done with it.
How did you conclude that the fuel pump is at fault?
I would get the correct fittings to go with the correct pump and be done with it.
How did you conclude that the fuel pump is at fault?
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Joined: Dec 2004
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From: Raynham MA
Ya, that's what I was afraid of.
So I guess the question is if that smaller fuel line coming up as a pair with the main fuel line is the return? It was capped off. So that needs to feed into the smaller pipe on the fuel line?
I'll take a look at some of my manuals to see if I can get more specifics, like what the return actually does and how to test that it is working. not sure why the PO capped it off. maybe it wasn't working?
As for why i think it was the fuel pump. No real good answer there. Just that the carb was just rebuilt and I have a new fuel filter and it was running fine until all or a sudden I would be driving and it was acting like it was starving for gas, bogging down. I made it home but then next time I tried to drive it I got it started for a few minnutes then it stalled. Finally won't start anymore unless I poor gas in the carb then it runs until that burns out.
Just figured I didn't know how old the FP was and seemed like a inexpensive fix. Would try that then see if I need to do anything else at that point.
So I guess the question is if that smaller fuel line coming up as a pair with the main fuel line is the return? It was capped off. So that needs to feed into the smaller pipe on the fuel line?
I'll take a look at some of my manuals to see if I can get more specifics, like what the return actually does and how to test that it is working. not sure why the PO capped it off. maybe it wasn't working?
As for why i think it was the fuel pump. No real good answer there. Just that the carb was just rebuilt and I have a new fuel filter and it was running fine until all or a sudden I would be driving and it was acting like it was starving for gas, bogging down. I made it home but then next time I tried to drive it I got it started for a few minnutes then it stalled. Finally won't start anymore unless I poor gas in the carb then it runs until that burns out.
Just figured I didn't know how old the FP was and seemed like a inexpensive fix. Would try that then see if I need to do anything else at that point.
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From: Raynham MA
I'm looking through the books I have but don;t see the detail I'm looking for. Wondering if it is normal to have 2 fuel lines coming up from behind. One is smaller than the other in diameter and in my case the smaller one is capped off. Is that the return? Do I connect that to the new fuel filter which has the extra connection for it? Just want to know before I do something stupid.
Also, should I be concerned that this smaller diameter line was capped off? Is it possible I may have an issue with it?
Also, should I be concerned that this smaller diameter line was capped off? Is it possible I may have an issue with it?
Race Director
Joined: Jul 2001
Posts: 15,892
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I'm looking through the books I have but don;t see the detail I'm looking for. Wondering if it is normal to have 2 fuel lines coming up from behind. One is smaller than the other in diameter and in my case the smaller one is capped off. Is that the return? Do I connect that to the new fuel filter which has the extra connection for it? Just want to know before I do something stupid.
Also, should I be concerned that this smaller diameter line was capped off? Is it possible I may have an issue with it?
Also, should I be concerned that this smaller diameter line was capped off? Is it possible I may have an issue with it?
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Joined: Dec 2004
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From: Raynham MA
Looking into this more. I think this is an Edelbrock performer RPM fuel pump. I kno my engine was rebuilt and they put an Edelbrock carb and Edelbrock Performer RPM intake on it. So it would make sense that they put an Edelbrock performer fuel pump on as well, I guess. Taking a look at a picture of the #1721 Edelbrock Fuel pump, look the same.
Might be easier for me to just get the exact replacement for what I have. Just that it costs twice as much.
Might be easier for me to just get the exact replacement for what I have. Just that it costs twice as much.
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From: Raynham MA
or save some money and do what opetes74ttop said. Use the one I have and plum the return line back in. Just hoping there is no reason I "need" to use the edelbrock one if my intake manifold and carb are also Edelbrock performer... Well, actually, i swapped out the Edelbrock 750 carb for a Holly 600. That another whole story..:-)
Instructor
Joined: Oct 2009
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From: Stanley NC
Another item that is often overlooked is the rubber S hose that comes from the steel line on the frame rail to the fuel pump. It costs only $12 if you get the correct one, don't even use a standard rubber hose. This is a simple replace job and worth the effort to ensure you have a good one in the system. Ask me how I know????? I replaced fuel pump, had tank cleaned out and more......and it was a bad S hose. Education is priceless. On that second small line I believe that is the return line to the tank. If bubba just used a 2 port pump last time probably just plugged it since did not have a place to connect. Best to have it in the system so I would go with the 3 port pump.
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From: Raynham MA
I have the 3 port pump that is recommended for the car as the correct replacement.
As for the 2 port pump, not that I'm trying to defend Buba
But he had the engine rebuilt and put on Edelbrock Performance RPM intake manifold, carb and fuel pump. That was probably why it is on there.
I think I'll just use the replacement fuel pump that costs $35 since I already have it and see no real reason to spend another $70 for the Edelbrock FP.
As for the S hose. Is that not rubber? I'm not familiar with with an S hose is. I'll see if I can look it up. Right now there is just some rubber hose connecting the fuel line to the FP. Then steel from the FP to the carb. Figure i need more rubber hose to reconnect the fuel return line to the new FP.?
As for the 2 port pump, not that I'm trying to defend Buba
But he had the engine rebuilt and put on Edelbrock Performance RPM intake manifold, carb and fuel pump. That was probably why it is on there.
I think I'll just use the replacement fuel pump that costs $35 since I already have it and see no real reason to spend another $70 for the Edelbrock FP.
As for the S hose. Is that not rubber? I'm not familiar with with an S hose is. I'll see if I can look it up. Right now there is just some rubber hose connecting the fuel line to the FP. Then steel from the FP to the carb. Figure i need more rubber hose to reconnect the fuel return line to the new FP.?
Instructor
Joined: Oct 2009
Posts: 165
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From: Stanley NC
Yes the S hose is rubber and it runs from the steel fuel line on the frame rail to the fuel pump inlet. This is supposed to be a reinforced rubber hose, not a standard rubber hose. If just standard rubber it is subject to soften due to the heat in the area and can draw in even on the inside and look normal on the outside, hence my problem. My hose was soft enough one could push it together even when cold so replacing it fixed my fuel lost problem. For $12 it is worth replacing with a correct hose to be sure you do not have a standard rubber on now. Can prevent stops in the future.
Melting Slicks
Joined: Oct 2002
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From: St Louis MO
The S-hose is molded into that shape. If you try to bend a straight hose, it will kink or at least restrict its diameter badly.
The 3 port pump returns a very small portion of the output back to the tank to keep the fuel in the main (3/8") line cool, avoiding vapor lock. It is best to use this small return line, but if it's not there, the 1/4" output may be simply capped off.
A few years ago, I cut open one of these 3 port pumps and found that the small line is simply fed through a small internal orifice .058" in diameter. With this knowledge, I added a small return line to my high volume Edelbrock mechanical fuel pump by plumbing in another fitting which is restricted by a .058" orifice. It works fine - no vapor lock problems with the '78 Vette, and it runs mid-11s in the 1/4.
The 3 port pump returns a very small portion of the output back to the tank to keep the fuel in the main (3/8") line cool, avoiding vapor lock. It is best to use this small return line, but if it's not there, the 1/4" output may be simply capped off.
A few years ago, I cut open one of these 3 port pumps and found that the small line is simply fed through a small internal orifice .058" in diameter. With this knowledge, I added a small return line to my high volume Edelbrock mechanical fuel pump by plumbing in another fitting which is restricted by a .058" orifice. It works fine - no vapor lock problems with the '78 Vette, and it runs mid-11s in the 1/4.
Melting Slicks
Joined: Mar 2008
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From: Austin Tx
You may be able to get away without using the molded 'S' line if you can reuse that 90deg fitting that is on the old fuel pump. With that fitting, you may not run into the kinking issue that results in using a regular line to a stock pump - ie. it wouldn't be making the double (S) turn, and would be a simple U turn.
If it was me, I would go back to stock. The return line is there for a reason. I would also get the "S" line, and not use the 90deg fitting. Getting it all back to stock will remove all confusion about what is going on in the future.
If it was me, I would go back to stock. The return line is there for a reason. I would also get the "S" line, and not use the 90deg fitting. Getting it all back to stock will remove all confusion about what is going on in the future.
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Joined: Dec 2004
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From: Raynham MA
After further investigation. Found some notes. the FP is a Carter M4891 that outputs 8 psi fuel pressure. It was put on the car with a Edelbrock 750 CFM 1411 carb. I now changed out the carb to be a 600 CFM Holly.
Question is: If I was to replace the Carter will that work OK with my Holly 600 CFM carb? Or do I need to use the Corvette replacement FP that is the correct replacement.
Any issues here I need to beware of?
Question is: If I was to replace the Carter will that work OK with my Holly 600 CFM carb? Or do I need to use the Corvette replacement FP that is the correct replacement.
Any issues here I need to beware of?
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From: Raynham MA
ok, that's good to know. Thanks.
So the only reason I am hesitant to use the OEM one is I'll have to spend more money and time "fixing" the fuel lines (such as getting the S hose) and the fuel line to the carb probably won't fit right either since the inlet and outlets on the new FP are in different locations.
Guess I was thinking using another Carter FP would match up exactly and require less work. ?
So the only reason I am hesitant to use the OEM one is I'll have to spend more money and time "fixing" the fuel lines (such as getting the S hose) and the fuel line to the carb probably won't fit right either since the inlet and outlets on the new FP are in different locations.
Guess I was thinking using another Carter FP would match up exactly and require less work. ?
