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I have installed a new fuel pump.... & the fuel pressure regulator I am using (Holley) I think is the 4-7 PSI model.. I am looking for the Holley 1-4 psi regulator. Is this what folks are using...
I want 2.5 Psi fuel pressure..
Also, do our cars use a fuel 'return' line? do I need to get a regulator that has this feature? I do not think my 'return' line is hooked up,, IF there is such a thing a a 'fuel return' line on these cars... FI cars I know have it... but on this ole NIKKI.... just don't know..
The stock setup uses a return line and no regulator. There is just a small restrictor built into the return setup.
I would recommend a stock fuel pump as long as you are running a stock Nikki and don't need a bunch of extra fuel flow. There are only a few reasons to deviate away from stock... The OEM pump is quiet/reliable, delivers the low fuel pressure the stock carb needs, and is not a pain to mount.
Most aftermarket pumps should be installed with a return style regulator for long pump life. I think that the 12A cars have a small return line (1/4"?) that do not flow enough fuel to keep an aftermarket pump and regulator happy. This was the case with my Mallory fuel pump and regulator .
the only difference between the 4-7psi holley and the 1-4 psi holley is the spring, so you can buy the rebuild kit for the low PSI model, and use that. or since the holley regulator isn't very good at regulating pressure, i've got a couple used ones i'd sell cheap.
the stock fuel system does run a return line, and i'll second the if you're running a Nikki, the stock fuel pump works great. plenty of flow, and pressure is rock steady.
stock pump with holley regulator has LESS flow, and pressure was all over the place.
Well, my fuel pump started acting up at the same time as the leading ignitor failure.... I replaced it with an EdelBrock That I think should handle the job....\
It's just this damn regulator....HOLLEY... my buddy had the same fuel pressure gauge & said it was garbage. IDK, if it is causing trouble or not??? ..It's MADE IN MIAMI, LOL So, I'm looking to replace that....
Problem is, the are a few fuel regulators at this $30 or so price range then it jumps to $170 - $250....LOL... with nothing in the middle.... still sorting this fuel issue out...
i did some checking, and the car had a 2" diameter 0-20 psi pressure gauge and i have a 5" 0-5 psi pressure gauge. both gauges agreed, but 2 psi on the small gauge is less than a needle width, so it was pretty useless
if you have the nikki, you are really better off with a stock pump, it moves plenty of fuel, and pressure is rock steady.
THX J9fd3s..... my plan was to replace the faulty fuel pump with one that can support more flow & psi... I plan to change the induction here pretty soon & I wanted a fuel system I could grow with..
car came with a Holley 'blue' (a spare) which was inop. before I even got it...LOL so, I got the EdelBrock fuel pump & the Holley 1-4 psi regulator....& I figured I'd be good... this set-up cost me less than an OEM pump would cost at around $130.00, unless I'm mistaken (on the cost) &the EdelBrock should be able to support more flow.. I am wanting a Camden SuperCharger.... but in the very near future, I am going to have someone customize a NIKKI for me to hopefully flow as much as a Holley 650 or something ... should gain me about 40hp with the other Mods on the car. Hopefully!!!
Hey there. Just picked up a new rig (1983 GSL Street Port). I'm getting way to much fuel pressure to my Holley carb (8psi). As it sits I have a Holley FPR with a return line goin' (stock 1/4"). The FPR isn't regulating low enough. So I check out racing beat and saw the Holley FPR they have suggested is only using one of the two outlet ports (identical FPR). Do I need that bypass line?
For the Holley 1-4psi regulator the two ports are just two options. You can hook one to the carb and one to a gauge, or just block off the un-used one. Return line goes back from the carb, no need to return one from the regulator.
I've got the second port on mine just plugged with an appropriately sized and threaded brass plug, then later I teed off the line halfway between my regulator and the carb to put in a gauge.
Someone mentioned it earlier, but if you want to measure a fuel pressure as low as 3.5psi (where I've got mine set) you need a gauge where that number is in the middle third of the range. Good gauges have a rating that looks something like this "3%/2%/3%" meaning that in the first and last third of the gauge's swing you could be +-3% whereas in the middle third you'll be off by 2%. This might not seem like a lot, but 3% of a 20psi gauge is 0.6psi. When we're aiming for 3.5psi that's a lot!
In my previous post I accidentally said Holley carb I'm actually running a Weber carb. Did some digging and the previous owner put a Holley blue fuel pump and a bypass regulator. So I'm swapping the FP for a Holley red. I also grabbed a 1-4.5 psi non bypass regulator. I was thinking about doing a dual regulator set up to keep the bypass line goin. I think it's overkill. (My old man insists) is the bypass that important? Also, as I don't know for sure. does the Weber have a return line? I didn't see anything on the carb. But there is something on the manifold.
Webers don't usually have a fuel return line so that's normal.
I honestly don't know if the combination of a non-return-style carburetor and a blocking-style regulator causes issues. In my setup there's always some fuel flowing through the regulator no matter what because excess fuel comes back via the carb's return line. But in your case the fuel would have to come to a complete halt if, say, you had the car off but the ignition in IGN position to run the fuel pump.
My guess (and it really is only a guess) is that your dad is right and you should probably be using a return-style regulator (which conveniently could use your stock return fuel line since your carb isn't using it), either as your only regulator, or if you can't find one that can drop the pressure low enough, at least have it before the blocking style one.
this is what Mazda wants for fuel on the race cars, i'd suggest a volume test after the regulator.
the Weber is kind of nice because you can set it up for the pressure you want, within reason. Mazda specs 4.3psi
07-03-18, 05:23 PM
