My mechanical fuel pump is starting to give me some problems. It delivers too much fuel pressure to my Edelbrock carb and causes flooding. It is on the hairy edge as it doesn't do it all the time. Today it was giving me grief AND it started to leak fuel from the seem on the fuel pump. So here are my options.

A. Replace my fuel pump with another mechanical pump and put a regulator on the fuel line.

B. Remove the mechanical pump and install a good electric fuel pump.

I'm leaning on the electric fuel pump option unless someone can give me a good reason not to go that direction.

 

Check my most recent thread for a reason not to use electric. Truck died, pump filled carb/cylinders/oil pan and ground with gas thanks to stuck float. I'd rather go back to mechanical.

 

Hi Steve, my 2cents -mechanical fuel pump will likely be cheaper and I think slightly more reliable. An electric fuel pump will for sure need to be regulated as memory serves, I think max inlet fuel pressure on a carb is maybe 6 or 7 psi. You'll also need to buy a block off plate for your mechanical fuel pump and of course wire it up.

From a safety standpoint, in the event of a collision and key is on, fuel pump will be energized (key on) even though engine might die. This would possibly lead to pumping fuel out of a broken fuel line. You won't have this with the mechanical unit, engine off - no pumping.

Noise will be another factor as many electric fuel pumps are noisy and produce a distinctive sound you might not like. Lastly there will be the mounting issue and needed bracket plus some new fuel line & fittings so the cost keeps going up.

I think the electric offers an advantage of pumping more volume at a higher pressure however if you don't have a set of Dominators you are feeding, then it will likely be performance wasted.

Oh and when it comes to reliability I think I read once that the majority of vehicle stalls are related to electronic reasons rather than mechanical - but I don't have the stats to back that...

Good luck with whatever you decide.

 

A fuel pressure regulator set at 5 or so psi should fix the excess pressure. You would need one with an electric pump also. If the mechanical pump is OK except pressure, I'd suggest the regulator is the simplest/cheapest/best fix. I understand Holly regulators are best.

 

Mechanical fuel pump and a good FPR (my Holley 12-803 is working great) set at 5.5 psi ...... and carry a low pressure electric pump in a box for backup if it worries you..

 

I just put a 12-803 on my cart at Summit Racing. Do you have any photos of your installation?

OK guys, I think mechanical is the way to go. I found a Carter fuel pump that will work. Now my OCD is kicking in, While I'm doing this, I might as well do that so I'm looking at some nice braided fuel lines and pretty fittings with a nice XRP fuel pressure gauge.

 

LOL

 

The real cool kids have a gauge before and after the regulator

 

I'll be "That guy," and say that I love my electric pumps. There are possibilities of problems with whatever fuel system you go with. Personally, I've had a mechanical fuel pump be sneaky about it's failure and fill my sump with fuel and it DIDNT stall the engine; just kept eating away at bearings with diluted fuel 'till I discovered the problem.

If you select an electric pump, unless you go with a good gerotor unit, expect some noise. I have a knockoff "Red top," that Summit sells as a house brand package with a pressure regulator that has worked well for YEARS, but was noisy and now sits switched to "Off," unless I need to prime the system after a long sitting spell.

You can do all kinds of cool stuff with the electric units, like running them through a Hobbs switch, which will shut it down if it doesn't sense oil pressure.

That will prevent the fuel pump from running and running and running if other systems fail, like in the thread mentioned above.

 

Pic for you, just in case.

 

Thanks Grinner, Any chance you could widen out your shot a bit to show the hose routing? I'm looking for some ideas as to locations.

 

I used brass barbed hose ends and regular gas line, but it'll look great with the braided stuff. I also made my mounting bracket and used longer studs at the carb's two front mount bolts, I had made it when I discovered that it interfeared with a vac hose, so I added an offset dead center. The fuel supply line from pump and filter goes into FPR at bottom center, then out back exit to carb.

I've checked it about a year after install using same guage and tee setup between FPR and carb, still dead on 5.5 psi .... so I didn't see a reason to add a gage under the hood.

If you added the guage, you can do it with a tee or use the unused port that I plugged. The extra line you see with short piece of copper tube is an extended vacuum line to PVC, not fuel.

I've seen pics of your engine bay, it'll look great there!

 

This is a good subject to bring up and psychlopath touched on it too. At a bare minimum, I highly recommend installing an oil pressure cutoff switch to prevent the pump from running with the engine OFF but key ON. Three-terminal switches with START and RUN inputs and 1/8-inch NPT fittings are easily available.

However, this does not prevent the pump from shutting off in a collision where the engine happens to stay running. Note, however, that the risk isn't any greater with a mechanical pump than it is for an electric pump with an oil pressure cutoff switch. You can cover this extra layer of safety with an inertia cutoff switch, but these are almost as expensive as the pump itself.

I'm in the process of installing a Carter P4070. I chose this over the Holley red pump because the instructions offered a little more freedom with regards to mounting. The Holley instructions are very adamant about placing the pump below the tank, although I'm sure some folks "cheat" without problems. The Carter instructions say the lower the better, but offer some maximum distance above the tank. In either case, closer to the tank and out of the engine bay is better.

My pump is installed, I'm just in the process of necking down the fuel lines. The pump was highly recommended and I'm interested in seeing the results. The reviews I've read say this pump does not need a regulator, as it is internally regulated to 6 PSI, and an Edelbrock theoretically is supposed to tolerate this.

Sounds like a moot point since the OP is going with mechanical. I think that's the most straightforward approach to the problem.

 

To me it depends on the situation. My '78 reg cab still has a mechanical pump, runs fine. My '48 was hesitating especially when it was hot out, beginning to vapor lock. Removed the mechanical pump and installed an electric pump, problem solved. My '78 crew was doing the same so I installed an electric pump next to the selector valve and used it to help push fuel to the mechanical pump. A couple of weeks ago I built and installed a new 466 and made an aluminum block off plate (have made many of them, very easy) for the mechanical pump and now I'm just running the electric pump. As far as noise goes, being all the way to the rear of the truck, no noticeable noise.

 

That's a nice plate; looks just as good as the store-bought ones.