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2bunik
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Question about fuel pump

Post by 2bunik »

Not on the s-10
I bought a holley red electric fuel pump today. but I do have question on it and I hope someone here can help me out since I dont go to any other forums. If I install the pump and it pumps at 6 psi to my carb.. how is it supposed to know the differance between fully open throttle and idle.. all it is, is a ground and key on power..? can someone shed some light.. Last thing I want is to either flood the carb or not get enough gas when I mash the pedal. thanx :oops:
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HenryJ
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Re: Question about fuel pump

Post by HenryJ »

2bunik wrote:...I bought a holley red electric fuel pump today....If I install the pump and it pumps at 6 psi to my carb.. how is it supposed to know the differance between fully open throttle and idle.....Last thing I want is to either flood the carb or not get enough gas when I mash the pedal. thanx :oops:
Unlike a mechanical pump the fuel pressure stays the same at all engine speeds. An advantage to mechanical pumps is that as demand increases , so does the pumps volume. They also tend to heat the fuel less during the process of pumping the fuel. (A good return bypass regulated electric pump is better yet since you do not lose the HP by driving a mechanical pump)
Holleys red pump is the street pump and does not have an external regulator if I recall correctly? The internal pressure relief maintains the 6 psi.
The needle and seat on the carb. should hold back 6 psi with no problems, and prevent flooding.
The float is what controls the fuel entering the carb. and prevents flooding.

What is it going on?

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Post by killian96ss »

What kind of carb are you using? Most Holley carbs can handle 8psi with no regulator. I had their blue pump with a regulator on a 390hp ZZ4 350 with a Holley 750, and it worked great set @ 7psi. The only thing I didn't like about this setup was that it had no return line, so the gas can heat up a bit especially in hot weather. Your red pump will work fine with almost any carb @ 6psi. I have experimented a lot in the past with carbs and fuel pumps, and I would be able to help more if I knew what you kind of setup your running like engine size, carb size and type (vacuum secondary or mechanical), horsepower, and volumetric efficiency.
Rusty

Post by Rusty »

I have a Holley red pump on the heater for my VW bus. Works great. I've have no fuel delivery problems, even on defrost!

(Now I sit and wait for the "What they h*ll are you talking about???" comments :lol: )
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Post by 2bunik »

I am running a ford 302 30 over, edelbrock 600 carb, mallory unilite distributor, crane cam (don't know the specs on that but it is mild) BBK headers, 289 heads (three angle valve job) All roller valve train, edelbrock performer intake, Griffin radiator, c4 transmission, B&M shifter. That is most of it.. then for fuel I was running a cheap stock mechanical fuel pump.. But it started leaking fuel so I went to Schuck's and scooped up the holley red. I bought the block off plate and some fittings. I would say its pushing about 300 hp at the wheels. I just use it to go to work and back ( 1/2 mile from where I live). :idea: I should walk.. or its sitting in the garage getting tweaked.. I was going to instal the pump but decided to ask you guys before I put fuel through it. My main concern was starving the engine of fuel when the pedal gets mashed. do you think that could be a problem? also like henry J brought up .. where is the excess fuel gonna go? :!: Am I missing something else on this setup..
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Post by 2bunik »

Should I go ahead and install it? with no regulator and no fuel return?
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Two 10s in a custom box and Pioneer Premier 400w amp, Quad mod,Body lift, bed light.
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Post by HenryJ »

You'll be just fine. The red pump doesn't use a reg. or return. It should be enough pump, if you do not plan to hold high rpm's for long periods of time.

In about a year ,if you drive much, plan on a rebuild kit for it and put a really good fuel filter in front of it (between the pump and tank). Be sure to mount that pump close to the tank. They do a better job of pushing fuel than pulling it.

I used to run twin Holley Blue pumps on the HenryJ. I went through six pumps and as many or more kits , in the last 13 yrs.
Finally got tired of them heating so bad in the street driving that I dumped them for Carters.

If you end up making a bunch of fuel line changes , make sure you have adequite line size. I would want a minimum of 3/8 line. (I run two 1/2" lines on the HenryJ)

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Post by killian96ss »

HenryJ wrote:You'll be just fine. The red pump doesn't use a reg. or return. It should be enough pump, if you do not plan to hold high rpm's for long periods of time.

In about a year ,if you drive much, plan on a rebuild kit for it and put a really good fuel filter in front of it (between the pump and tank). Be sure to mount that pump close to the tank. They do a better job of pushing fuel than pulling it.

I used to run twin Holley Blue pumps on the HenryJ. I went through six pumps and as many or more kits , in the last 13 yrs.
Finally got tired of them heating so bad in the street driving that I dumped them for Carters.

If you end up making a bunch of fuel line changes , make sure you have adequite line size. I would want a minimum of 3/8 line. (I run two 1/2" lines on the HenryJ)
I totally agree with what HenryJ said. There are a few other things that I would like to point out. The filter before the pump is a good idea, but don't forget you still need one before the carb. The pump must be mounted lower than the tank, and you should have a sump welded to the lowest point on the tank to prevent pump failures caused by air pockets and the pump just working too hard to pull the fuel through the system. The sump thing is not a must, but it will help the pump a whole lot. You can get by with 5/16" fuel line, but 3/8" is definitely much better for higher volume. Make sure you run a relay and fuel pressure cut off switch in case of an accident. The switch usually mount to the block sensing oil pressure, and when the oil pressure drops below 10psi the switch will cut power to the pump. The switch is also not a must do, but rather a safety item. Also make sure you are getting the right voltage to the pump with adequate size power wires. I have also used Holley's blue pump on a 390hp ZZ-4 crate motor in a 68 Impala for about 4 years without having to rebuild the pump once. The only thing I don't like about your setup is the the Edelbrock carb. I have used several of them (Edelbrocks & Carters) with no good results. The newer Holley Avenger carbs are 100% better than the Edelbrocks, and I think they are much easier to tune. When I switched from Edelbrock to Holley the difference was amazing to say the least. :roll:
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Post by HenryJ »

killian96ss wrote:Make sure you run a relay and fuel pressure cut off switch in case of an accident.... a safety item.
Amen
I have also used Holley's blue pump on a 390hp ZZ-4 crate motor in a 68 Impala for about 4 years without having to rebuild the pump once.
I'm probably running a bit more corrosive fuel and maintaining 9 psi probably wasn't helping matters. The teflon bushings in the motor were the worst of my problems, causing a drop in fuel pressure when they heated (one siezed during a race).
The only thing I don't like about your setup is the the Edelbrock carb. I have used several of them (Edelbrocks & Carters) with no good results. The newer Holley Avenger carbs are 100% better than the Edelbrocks, and I think they are much easier to tune. When I switched from Edelbrock to Holley the difference was amazing to say the least. :roll:
I'd agree that the Holley's are a good choice for best performance, but I've had good luck with the Carter's for daily drivers. It seems to me that you always need to adjust the Holley's to keep them running right, where the Carter (Edelbrock now) runs until it needs rebuilt. I have never been able to get the Carter to run right again after a rebuild though.
The Carter is better than a Holley for a 4x4 , since it is less likely to starve the main jets during off level operation.
Last edited by HenryJ on Wed Mar 17, 2004 12:37 pm, edited 1 time in total.

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Post by killian96ss »

HenryJ wrote:The Carter is better than a Holley for a 4x4 , since it is less likely to starve the main jets during off level operation.
I would have to agree completely, and the spring loaded needles also help for bouncing around off road. The Carter's are definitely more user friendly, but I have found that when you get a Holley tuned just right it makes more hp and torque, but it's all about getting the right jets, and power valves to work in combination with the vacuum secondary springs, which sometimes takes a million trial and errors, but works great once you have figured it out. :D
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Post by 2bunik »

I recently started working on cars about four years ago.. But I have two other hobbies that I keep up with to. I Love Graffiti, and MAGIC. So I have worked alot on learning as much as possible about cars .. I have not yet learned anything about carbs and transmisions. I know the basic concept But not how to rebuild them. I eventually get around to it but as of now it is the last of my worries.. I have worked alot on my troubleshooting skills . thanks to my friend Jesse who is ASE certified. I just got me a 2,500 page book I am reading.. has many troubleshooting senerios and ASE questions. Alot of info on the modern technology that I really want to learn.. The book doesnt have anything on high performance though. and that is why I ask you guys.. ok so after my biography.. The fuel pump is a go.. One problem I have is I have to mount it in the engine bay.. I mean I dont want to but it would be a Royal Pain in th A to mount it by the tank.. what do you think.. I dont think the pump would have trouble pulling cause I can suck on the 3/8 hose beofre the pump from the bay and gas comes rushing up.. ?? :!:
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Post by AZS10Crew »

It may be true that the fuel flows through the hose easily at first, but over time, the pump will wear out faster without gravity (and a shorter hose) helping a little. There's no place on the frame rail near the tank to mount the pump? I think that's where most people usually put them.
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Post by killian96ss »

AZS10Crew wrote:It may be true that the fuel flows through the hose easily at first, but over time, the pump will wear out faster without gravity (and a shorter hose) helping a little. There's no place on the frame rail near the tank to mount the pump? I think that's where most people usually put them.
Near the tank, and as low as possible is you best bet like AZS10Crew said. When I did this on my old 68 Impala I had to fabricate a bracket to mount on the frame rail near the tank, because I ran into the same problem of not having anywhere near the tank to mount it, and it needed to be lower than the tank for a good gravity feed. After doing this I also made a nice shield to protect the pump from flying debris. I would not mount the pump in the engine compartment as the pump will be working way to hard and will more than likely fail prematurely.