I know it sounds like a dumb question but there are no such things as dumb questions just dumb people so please enlighten me. The rx7 I have came with an aftermarket fuel pump and fuel regulator on it, and it has the stock nikki carb. I am wondering if there is a way to adjust the regulator or if it automatically adjusts the pressure. I have never messed with a regulator before so I don't know anything about them other than what the purpose of it is. The reason I ask is just to check off another possibility that could possibly be linked to my problems in other posts.

 

Need details on the model pump and model regulator. Also is this for a stock nikki
or some other carb?

I think the nikki is very sensitive to correct pressure which should be about 3.5
psi, no more. Someone with a nikki needs to verify.

Each carb will have different requirements.

 

hopefully it is adjustable, otherwise its a bit pointless.

the PSI you end up with will vary a little, probably mostly because the average 0-15psi gauge isn't accurate in the 1.5-2.5psi area.

so the carb wants to see around 2psi, and if you don't buy a good gauge like Re Speed sells, then you have to use the butt dyno

 

Its true...I have a holley red pump with profuel reg set at 3lbs...it runs identical on the 2lb setting and even 1.5! I figure my fuel gauge is suspect, but it shows correct pressure until everything warms up. Then it can be off as much as 1.5 lbs

 

yeah its relative, if we used my gauge it would read a different number, but the car would run the same.

 

I have the same issue with my Holley gauge. I can adjust the regulator and the gauge will show anywhere from 0-4 PSI, but the car runs the same. You think it would at least lean out on the open road with "0 PSI."

Bahlorm, chances are it's a Holley regulator or something very similar. There should be a nut on one side with a threaded bolt sticking out from it. That bolt has a hex head inside of it for an allen wrench. You have to pop the outer nut loose first with a 5/8" and then you can turn the threaded bolt with with an allen wrench or even your fingers if it's loose enough. Turn it clockwise to raise the pressure and counter-clockwise to lower it.

 

Okay I will give it a shot lizard thanks. I have no idea what kind of pump or regulator is on it, all I know is he put in a pump that produced 7 psi which overloaded the nikki carb and then afterwards he put in a regulator. So I am not even sure if it is adjusted correctly and could be the reason why my car running ungodly rich

 

More than likely.

 

Okay, I have jacked the car up and looked under it and I saw it has those universal 12v micro fuel pumps, I then didn't see a regulator anywhere around the fuel pump and definitely not in the engine bay. So my question is if I am a regulator where would I be? Right now my guess would be at an auto parts store because he lied and never put 1 on to begin with, but I may just be looking in the wrong places?

 

usually they are mounted up by the carb, cant see why he would put one under the car... that'd be a PITA

 

Yeah there isnt anything on the fuel lines in the engine bay other than an extra fuel filter for some odd reason. I just went out with a fuel tester, supposed to be for fuel injectors but say it tests all model mazda down to 1980 so I just wtf why not see what it says, it is really hard to determine exactly the pressure of it but it was real close to the first notch which would be about 5 psi lol.

 

Okay scratch that above. I looked everywhere on the fuel line to see that there wasnt a regulator at all. So I went out and bought a holley regulator that is for 0-4 psi and a gauge that registers that low. Now I put the gauge on and it tells me I am getting 1 psi of pressure, and now it dropped down to 0. I highly doubt I put the gauge on wrong since it just screws into the top of the metal piece then connects 2 fuel lines to it but yeah.... I don't have the regulator on there yet because it kept leaking on me and I have run out of time. But this is where I have gotten so far, and I suspect that the problem I am having is in the fuel system instead of a vacuum problem.

 

Sounds like you found your issue, no regulator.

That holley model should do the trick its what I have on my dell. Note that the in line fuel pressure guages are mostly junk that you get for 10 or 15 bucks at the auto parts stores. I splurged and got a fluid filled one from jegs which is 0 -15 but even its not accurate down that low and after it heats up it reads at 1 or 1.5 psi which is I know is BS. I just use as way to make sure when its cold that I have the regulator adjusted about where it needs to be then I further adjust the regulator by sound very carefully. I just opened it in 1/4 turn increments until the carb starts to bumble a bit which means its pushing past the needle than back it down a bit.

You get the fuel pressure down nearer to where it belongs and you'll be a
happy camper I bet.

 

FYI, those noisy little micro pumps are garbage. I got one that leaked, and the replacement gave sporadic pressure that made my car run like ****. I finally just got my money back. An upgraded pump is money well spent.

Use a liquid thread sealant like locktite on the threads of all the fittings when you put the regulator and gauge together. Be careful not to overtighten anything. Once you get the leaks fixed, follow T G Farrell's instructions.

 

Just did all that, got the regulator in the gauge in which is reading 2 psi I found out there was another fuel filter (which makes 3 on this car) on the pump and it was completely clogged so I thought that might help a lot to replace! I replaced it just to have my pump go completely out on me. Found out this awesome pump only pumped out between 2 and 3 psi, so I went and got another pump that pumped up to 7 and regulated it down to 2 again. So with that all replaced unfortunately I am still having the same problem, it is just not as bad. I got the car to idle down to about 800 rpm instead of 1500 and it idles much smoother, but still hesitates

 

Oh and I also just got gas and found out that I am currently getting a full 16.5 mpg on average after almost 170 mile. Which is twice as much as I was getting with the chevelle I have been driving daily lol. But I would hope to get at least around 20ish.

 

with a good running stock 7 i was getting average 22-23 country driving

 

Yeah whatever this cause is its eating through my gas. But at the same time it might not be too much because it has been idling/revving for at least a total of around 2+ hours, plus with fuel leaking trying to get the regulator on so it may not be too bad

 

Get it running right before worrying about the mileage. Like for a few weeks, then
start working on the mileage. Oh and yeah all that idling and fiddling with the carb
and what not probably wasted a bunch of gas.

 

Yeah probably lol, plus with the problems its got right now I am sure is causing gas milage to lower

 

Currently now I have a mr gasket 7 psi pump that will work until I can afford to get the pump from racingbeat, the holly regulator and this gauge that cost me $30 that's supposed to read accurately down to 1 psi and got it all running between 2 and 2 1/2 psi. So hopefully that is all set up correctly, I don't thing I have ever had to do so much work with a fuel system as I have done with this car lol. Mostly all new rubber lines so the fuel should be in good shape now