problem getting 350 started

[SirRobyn0]

I just realized that I had never checked what the fuel pump specs say for the replacement pump on my truck. I ordered it from Rockauto and paid for the more expensive ACDelco unit. Turns out the specs for every pump listed for my 1980 K25 5.7L says that pump pressure is rated for 40GPH @ 7.5-9PSI.... Every quadrajet source I have found says that pump pressure should be no more than 7 psi and ideally should be 6 PSI. The only pump on rockauto that listed a minimum pressure lower than 7.5 was a Carter unit that listed 2.0PSI minimum and no maximum.

I was curious, so I went to autozone and NAPA websites. Autozone lists the exact same pumps, but with no pressure ratings. NAPA only has their own brand pump, but also listed as 9 PSI maximum pressure.

Airtex. 40725 looks like an affordable alternative to an edelbrock pump jegs and speedway also listed some low pressure pumps Didn't mean for this to post twice anyways that Carter pump I saw that too I tbink it was an m4651? I'd think it's a safe bet. Most of the pumps I saw were only showing about a 2.5 LP spread like 7.5-9 psi so I'm thinking that Carter has gotta be under 6 I'd gamble with it

I have noticed the high specs on the replacement pumps but never went out of my way to look for a lower rated pump. That is some good information for sure. I can justify the $21 for the airtex pump a lot better than the $100+ for the Edelbrock. As some of you already know the Edelbrock performer is a direct descendant of the Carter AFB, which leads me to wonder if the low pressure Carter pump is the same pump as the Edelbrock, just with a different name and pricing, which for a while Carter AFB's and Edelbrock performer carbs were available at the same time, just with differant pricing and edelbrock was chrome, where as the AFB was not. Interesting info.

 

[curse]

I ordered a 5 psi fuel pump. It was around $23 from rockauto, regulator leaks and adds too much clutter to my motor anyways.

 

[Bextreme04]

I ordered a 5 psi fuel pump. It was around $23 from rockauto, regulator leaks and adds too much clutter to my motor anyways.

What was the part number?

 

[curse]

MF0001

Package Contents Mechanical Fuel Pump, Gasket, Instruction Sheet
System Pressure 5 PSI
Inlet Outside Diameter (in) 0.375
Fuel Type Gas
Gasket or Seal Included Yes
Inlet Type Hose Bead
Outlet Type Threaded
Outlet Quantity 1
Inlet Fitting Thread Size 5/8 in. - 18 UNF
Average Flow Rating (GP) 40

 

[SirRobyn0]

I ordered a 5 psi fuel pump. It was around $23 from rockauto, regulator leaks and adds too much clutter to my motor anyways.

MF0001

Package Contents Mechanical Fuel Pump, Gasket, Instruction Sheet
System Pressure 5 PSI
Inlet Outside Diameter (in) 0.375
Fuel Type Gas
Gasket or Seal Included Yes
Inlet Type Hose Bead
Outlet Type Threaded
Outlet Quantity 1
Inlet Fitting Thread Size 5/8 in. - 18 UNF
Average Flow Rating (GP) 40

Please let us know how it works out for you.

 

[curse]

Please let us know how it works out for you.

Of course. Sounds like I should see the pump by next Friday.
Side note: The lower pressure did make the motor run at a normal idle finally but I didn't run it long due to the leak.​

 

[idahovette]

Jeez Kyle, my old eyes can't read those black letters!!

 

[SirRobyn0]

Of course. Sounds like I should see the pump by next Friday.
Side note: The lower pressure did make the motor run at a normal idle finally but I didn't run it long due to the leak.​

At least now you know fuel pressure is the problem. I'm just curious the regulator that you bought that leaked what brand was it. I have seen them leak, but it's not all that often. On another thread months ago I lamented the fact that most people, including myself, and even when installing them on customer cars, usually mount them inline on top of the manifold. I was bitching about the possible fire hazard if the regulator were to leak and the gas went back towards the distributor. We discussed mounting them on the firewall vs inner fender well. With that said, I can only think of two that leaked and it was just like yours it happened immediately after it was installed so likely a factory defect. When I've seen them go bad after years of use it's because they either get plugged up inside or just stop flowing enough fuel under load. It's just another rabbit hole to go down

 

[curse]

Spectre performance 2519, it was only $24.10. I know it's a cheapy but I wanted to see if pressure actually is my problem. If so I planned on a quality regulator.

Then I find out about lower pressure pumps which is what I would have done before the regulator.

 

[Rusty Nail]

Dude Ive never added a fuel pressure regulator, in my life.

 

[curse]

Dude Ive never added a fuel pressure regulator, in my life.

Neither have I but it seems like my current pump has some power! I've never even known someone having to use a regulator.

 

[Rusty Nail]

Me either but we really like makin easy things hard around here it seems of late.

I stay out of it mostly.

 

[SirRobyn0]

Spectre performance 2519, it was only $24.10. I know it's a cheapy but I wanted to see if pressure actually is my problem. If so I planned on a quality regulator.

Then I find out about lower pressure pumps which is what I would have done before the regulator.

I have to say I've never used that brand. Will be interested to see how the pump works out.

Dude Ive never added a fuel pressure regulator, in my life.

Me either but we really like makin easy things hard around here it seems of late.

I stay out of it mostly.

@Rusty Nail, yes you do (stay out of it mostly) and sometimes I think that makes you the smarter guy. I always feel the need to say what has worked for me because I've seen so many of these problems before, but I have to say I've also learned some new things as well. Sometimes I think it would be so much easier for me if I would just shut up.

 

[Rusty Nail]

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[SirRobyn0]

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Thanks a lot!