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Discussion Starter #1 (Edited)
So i bought an inline fuel pressure gauge (not liquid filled) and hooked it up between the inline filter and carb. It bounces around, from 6-9...

I know i should be around 5.5-6. Could the gauge not being liquid filled cause discrepancies in the readings or is it just time to upgrade my fuel system? As of now, it's all stock.

If it's upgrade time what systems would you recommend? Im on a budget so i cant get to fancy.

BTW i have a 350 sbc

Thnx
 

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If possible, could you describe the "stock" components you have? What brand of fuel pump, what kind of carb, what size fuel line from the tank to the pump, what size fuel line from the pump to the carb, etc, etc...

The more information you provide will give someone in this site some clues to what's happening in your situation...
 

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Discussion Starter #4 (Edited)
If possible, could you describe the "stock" components you have? What brand of fuel pump, what kind of carb, what size fuel line from the tank to the pump, what size fuel line from the pump to the carb, etc, etc...

The more information you provide will give someone in this site some clues to what's happening in your situation...
Im sry, im usually more descriptive


i have an edlebrock 1411 750 carb the hose diameter is 3/8's. From the carb it goes down to the gauge, then the filter...

...to the fuel pump

From the big AC stamped on the side, i can only assume it's an AC Delco pump.

I'm going to buy a liquid filled gauge tomorrow, just looking at the gauge as i was buying it, a little voice in my head was screaming "this thing is garbage!" But of course i still bought it. It fluctuates with the idle of the motor and i think a liquid gauge would prevent this.

I'm also thinking i should shorten the hoses between the filter to gauge and gauge to carb.

What do you guys think?
 

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I would definitely shorten it and get it away from that exhaust!!!!

You might want to route that fuel line closer to the intake vice near the top of the headers. You will need to put a 90 degree fitting on the inlet of the carb and run that hose to the front part of the motor.

As for the 750CFM Eddy, I think you need to be at 7-9psi to make it driveable. Of course that stock pump will cavitate if you were to mash the throttle. You might need to step up to an Eddy or Holley mechanical fuel pump to be on the safe side.


Dan
 

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Discussion Starter #6
Sounds good, i'll go to autozone today and buy a 90 degree fitting, liquid filled gauge, and then reroute the fuel line.

I'll check out the fuel pumps on summit, any reason not to go electric?
 

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On manual fuel pump the bounce (Pulse) is normal.
Especially at low RPM.

Factory manual fuel pump is a pulse pump.


FYI
Al
 

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I think the pump is failing. That mechanical is probably self regulated, so the supply is varying and too low. Pumps are cheap.

Like Dan suggested, get rid of that nasty fuel line before it catches on fire!

rob
 

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On manual fuel pump the bounce (Pulse) is normal.
Especially at low RPM.

Factory manual fuel pump is a pulse pump.


FYI
Al
X2!!!
It operates off a lobe on the cam.

Also.....Don't bother wasting any money on a liquid filled gauge if it is going to get mounted under the hood. The under-hood temps will be too high and the gauge will not read correctly.:no:

And YES...... Reroute that fuel line away from the exhaust!!!!! Better yet, run a steel line and do away with all of that rubber line.
 

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Discussion Starter #10 (Edited)
On manual fuel pump the bounce (Pulse) is normal.
Especially at low RPM.

Factory manual fuel pump is a pulse pump.


FYI
Al
Thanks for the info Al

FYI, your "FYI" wasn't necessary and came off as pompous...

Anyways, i just bought all the components to reroute my fuel lines, honestly it's really not that close to the header, but i've wanted to clean it up for awhile anyways so ill do it today.

D-man, thnx that explains why it bounces with the idle, should i go electric? Luckily the auto parts store didnt have a liquid filled one, thnx for the info, ill stick with the one i have.

As for the sh**** black hosing, i hate it too, and will completely remove it once i decide which pump system to buy.

Thnx
 

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it's in a lot of his posts, just like the imho (in my honest opinion) the FYI is just letting you know something... he's not being crass or pompous. :no:
 

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Discussion Starter #12
I understand, and im not necessarily say it was pompous, just that it could come off that way to some ppl.

Obviously the post was for my information and i didnt need an FYI to confirm that, that's all i'm saying, and i really do appreciate the info because it let me know why the gauge was bouncing.
 

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My gauge bounces between 5-6 psi at idle. Its an inline gauge just before the carb, looks somewhat like yours.

I agree with the others, the less rubber fuel line you use the better. At a minimum you could use rubber line off the pump and then bend up some steel line to get up to the carb, then a small amount of rubber line to the carb. I had that setup for years with no problems. Since then I routed braided steel line with fittings to the pump, and from the pump up into the carb. It was more expensive so I didnt do it until later.

The further you can get the fuel line away from the motor and exhaust the better. I've seen some cars where the fuel line is touching against the engine block, obviously thats not good. If you're unsure of what would be a good idea, I'm sure you could start a new thread and ask for engine bay fuel line routing pics, etc. That would give you a lot of ideas as well if you were considering re-routing things.

I think Al was just trying to help out. His comments are usually short and to the point which is nice (unlike mine which include a lot of rambling, haha!). He's a nice guy though. Text really limits the true expression of what someone is trying to say sometimes I think.

You might be ok with 7-9 psi on an Eddy carb, some guys seem to have no problems, but the Eddy carb manual specifically states no more than 6 psi of fuel pressure to the carb. Most fuel pumps put out more than this, but there are some that put out 5-6 psi. The carb manual states that 5.5 psi is optimal fuel pressure for the carb to function properly. I'd try to shoot for that if I were you. You could keep your current pump and run a regulator to the carb, or just try to find a pump that only puts out 5-6 psi and skip the regulator.

Good luck man!
 

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fuel line routing

Here's a few pics of how my fuel line is routed to and from the pump to the carb just for reference. Not saying mine is 100% correct or the only way to do it, just showing you to give you some ideas. I've never had any issues with vapor lock or fuel leaks/fires, etc.





 

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Thanks for the info Al

FYI, your "FYI" wasn't necessary and came off as pompous...

Anyways, i just bought all the components to reroute my fuel lines, honestly it's really not that close to the header, but i've wanted to clean it up for awhile anyways so ill do it today.

D-man, thnx that explains why it bounces with the idle, should i go electric? Luckily the auto parts store didnt have a liquid filled one, thnx for the info, ill stick with the one i have.

As for the sh**** black hosing, i hate it too, and will completely remove it once i decide which pump system to buy.

Thnx
I'll remember that next time you need free advice.

Dam right I will.



Al
 

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Discussion Starter #18
I'll remember that next time you need free advice.

Dam right I will.



Al
Lol, ok clearly i have aggravated you and i want to start off by saying im sorry Al. Carls right, sometimes emotion and how things come off through text can be construed and misinterpreted and i majorly jumped to conclusions. You've helped me out a couple of times, just as you did here and i should have noticed from your past posts that you are a man that cuts to the chase. Again i'm sorry

Carl I like the way you spell things out and what may come out as a "rant" to some people, i find very informative and helpful.

I've rerouted my system (i think) to the best at which the parts i have on hand will allow.



I'm still using the hosing for now and will definitely be using braided line when i upgrade my fuel system in the near future. I tried to use a 90 degree fitting like you used carl but of course, when screwed all the way in points towards the driver side. I was going to shorten the hosing but found when i did so it kinked near the fuel pump.

Im worried the hoses are to close to the heater and lower radiator hoses so ill have to find away to fix that.
 

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X2!!!
Also.....Don't bother wasting any money on a liquid filled gauge if it is going to get mounted under the hood. The under-hood temps will be too high and the gauge will not read correctly.:no:

.
I have had two of the liquid filled guages and both worked fine when the engine was cool. As soon as the engine heated up the guage pressure slowly dropped off. The car performance didn't change and I'm pretty sure my car had more than zero fuel pressure.
 

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Lol, ok clearly i have aggravated you and i want to start off by saying im sorry Al. Carls right, sometimes emotion and how things come off through text can be construed and misinterpreted and i majorly jumped to conclusions. You've helped me out a couple of times, just as you did here and i should have noticed from your past posts that you are a man that cuts to the chase. Again i'm sorry

Carl I like the way you spell things out and what may come out as a "rant" to some people, i find very informative and helpful.

I've rerouted my system (i think) to the best at which the parts i have on hand will allow.



I'm still using the hosing for now and will definitely be using braided line when i upgrade my fuel system in the near future. I tried to use a 90 degree fitting like you used carl but of course, when screwed all the way in points towards the driver side. I was going to shorten the hosing but found when i did so it kinked near the fuel pump.

Im worried the hoses are to close to the heater and lower radiator hoses so ill have to find away to fix that.
What happened to your fuel filter?

And for what it's worth, my underhood fuel pressure gauge is more of a "got fuel?" gauge. The little guys are usually not very accurate at all.
 
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