# Replaced Fuel Pump! Still runs bad...



## 5hundo (Sep 10, 2007)

I described my problem a few weeks ago but I thought it was a lack of fuel supply. Well, I replaced the Holley Red pump with a Holley Blue. 

...that did no good. 

I think I'm going to rebuild the carb and replace the fuel rail. That way, I know I've got a fuel system that's 100% good to go.

What else could this be? I've heard timinig might be a problem...

What else?


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## Rukee (Feb 8, 2007)

We need more information, what kind of car, engine, what`s the problems your experiencing?


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## Nick! (May 12, 2008)

Did you consider the fuel filter?


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## 5hundo (Sep 10, 2007)

Nick! said:


> Did you consider the fuel filter?


Replaced it when I put the new pump on, so it's brand new...


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## 5hundo (Sep 10, 2007)

Rukee said:


> We need more information, what kind of car, engine, what`s the problems your experiencing?


1967 Le Mans with a 455 and a Holley 750...

It idles fine but as soon as I put a load on it, it dies. I can even rev it up, without issue but as soon as I put it on the road, it dies on me. 

Vacuum system? Carb needs rebuild?

I dunno...


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## Rukee (Feb 8, 2007)

Looking down the throat of the carb, can you see it spray a steady stream of gas as you pump the throttle? In other words, is the accellerator pump working?


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## speedwrenchx10 (May 6, 2006)

What kind of ignition?If it is converted to GM hei distributor unplug vacuum advance hose and see if it will accelerate.The vacuum advance may be pulling the pick up coil wire apart causing no spark.Cover carb with hand when trying to rev if it helps could be lean.Rusted through suction side of fuel line can cause fuel pump to loose prime.Hope this helps.


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## 70455goat (Nov 5, 2007)

5hundo said:


> 1967 Le Mans with a 455 and a Holley 750...
> 
> It idles fine but as soon as I put a load on it, it dies. I can even rev it up, without issue but as soon as I put it on the road, it dies on me.
> 
> ...



A FEW IDEAS -
1. I had a bad coil that gave me similar indications. I had a points distributor and a stock coil. The coil would work fine until it got warm or when it was under a high spark condition. Then is would just quit working.

2. As basic as it seems, my son's chevelle had similar indications and it ended up being a clogged PCV valve. Idle is about all it could do. The engine couldn't breathe.

3. My 65 Impala SS had a similar problem and it ended up being a hairline crack in the distributor cap. I actually tore the whole engine apart and still didn't fix it. My next door neighbor came over and ripped the distributor cap off and put on a new one one and it ran perfect. I would have never thought of a crack in the cap.

4. Broken down plug wires also have caused me trouble before.

5. Check vacuum and where the vacuum is being pulled from on the carb. I am not an expert on which vacuum you are supposed to use (ported or manifold), but I know it made a difference when we were trying to get the chevelle running again, after the engine was rebuilt.

Good luck. I hate when I can't figure out what is going on.

Dale


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