sgieldon

After going threw (2-Holley, 1-Stewart Warner, 1-Mallory) Fuel Presure Gauges I'm getting readings of 2-3 P.S.I. Difference @ Idle and WOT????

Please don't suggest Check This and Check That!!!
Just looking for a Straight Forward Answer on your Experience.

A quick FYI.
RB Holley, Streetport setup w/ Center Hung & Dual Feed
MalloryComp140 w/Reg
Set @ 6psi

Each Gauge gave me different readings no matter what I tried???
All where checked being taped to the windshield and mounted directly to the Regulator.

Thanks for any Recomandation i.e. Gauge that actually Reads Correctly.
sgieldon
steve
P.S. How was the Race on Sunday here in Eugene? Icebreaker39
I had to go to Seattle over the weekend to Breakup with the Woman!
to much distance for relationship.
Mike and Jeff-Did you Guy's Race???

Siraniko

iTrader: (13)

there will be different pressure @ wot and idle. At idle, the carb doesnt require much fuel. Therefore, the fuel bowl is closed and fuel pressure stays at the line. At WOT, the pressure will drop as the pump is feeding fuel to the bowl. Think about a garden hose. Close the spray nozzle and you will notice that the hose will get somewhat expand. early in the morning, Im not sure if I explained that correctly. I need beer.

sgieldon

Hey Wackyracer;
I understand all that!!!
I just need a Gauge That's Accurate.
I called Mallory this morning and they Guarantee me that there Model # MAA-29724 will match up perfectly with my Motor-Carb and Fuel Cell Setup.
All 3/8 from Tank to Carb w/$350.00 invested to get the Gas to the Carb.

I'm just looking for info on Experience with Fuel Gauges.
Thanks for the Input.
sgieldon
steve

P.S. Wackyracer;
Thanks for your input as always. It's of great value that you and other members of this board try to help each other through our Daily-(Lets Try This or That) that makes the Rotary World Survive.
I like how we and you try to help as much as possible.

OK DavidGrimes; Kick in here any time now.
steve

Tom

Have you tried Yaws 0-5psi gauge? http://www.yawpower.com/gauge.html

Siraniko

iTrader: (13)

steve
If I were you, instead of buying of buying/trying out different gauges, I will install an in-line fuel pressure gauge; that’s in addition to the gauge/FPR combo. SUM-G1710. Thats what I have used to diagnose fuel pressure problems in the past.

sgieldon

I thought about that setup at one point but since I'm running the gauge straight off the Mallory FPR #MAA-4305M Three Port Reg.
No point in that setup.
Like I stated before,-I taped the Gauges to the windshield to watch the difference between all ranges of driveing my BaBy. o.e. Idle-WOT-65-90-120-138 on a Sunday that's about as Fast as I can Afford for a Ticket in a 65mph posted!!!
I did however kick the **** out of a 300ZX in all the above. So my Fuel issue can't be that far off.
Thanks Again
sgieldon steve

Siraniko

iTrader: (13)

you may wanna put a jet between the soft return line and the hard line to regulate the flow back to the tank. Thats to ensure that you will get the proper pressure at the carb

vipernicus42

iTrader: (4)

What you need to do is read Paul Yaw's big rant about fuel pressure gauges.

Read my summary of the problem here:
https://www.rx7club.com/showthread.p...ghlight=gauges

While I go and find the original article.

Paul Yaw has a gauge that will give you an accurate read. I just have to find it.

Jon

vipernicus42

iTrader: (4)

Here's the article:

http://www.yawpower.com/fueldel.html

And he sells the gauge for about $50. I know, it's BLOODY expensive, but it's the best damn gauge you can buy and you'll only have to buy it once. Oh.. and it doesn't get permanantly mounted, only when tuning.

Jon

Edit: And you can buy the gauge here:
http://www.yawpower.com/crbacc.html

Edit on the Edit: I guess I forgot to read the announcement on the contact page that the shopping cart is under construction. So I guess you have to e-mail him or call him. In the past he's been a little slow with e-mails sometimes, but hopefully you'll hook up in a timely fashion.

Tom

Look a few posts up. Already pointed to Yaws site...

sgieldon

Fuel Return Line is Non Existent.
All of the Orginal Fuel Sytem is in the Dump. Too Include the Fuel Tank.
This is a Brand New steup.
84GSL 12A Pineapple Racing WeedWacker Motor that scares the Hell out of any Passenger and Kicks the *** out of anyone that F.K.S with Her.

Everyone that see's the Car goes.
Nice Car for 20yrs Young.
Then you either POP the Hood or take them for a Spinner or Both:
Ya Get A WOW Man.
After owning 6 RX's in the past. I must say (I'm Proud Of This Project).

Now if I can just clear up my 2 Delima's in the last couple of weeks I can move onto the next????

1-Accurate Fuel Pressure Gauge
2-Get my FKN Cruise to work.
I drove from Seattle last night @3am and could of used it @ least twice.
Thanks Again
sgieldon
steve
If someone can explain how to post pictures here without getting the Image to Large Message, after 3 yrs+ of posting here it's about time that I show some of my past Cars to include this Babe

DAVID GRIMES

You've hurt my feelings. You have a valid question that I can't answer. I run a noisy holley red. I will change to a Mallory some day for the quiet.

My experience with fuel pressure gauges are:

1) My purolator regulator had no gauge except the numbers on the dial. It fell apart and soaked the engine compartment. I think they are crap.
2) I have a holley regulator and NOS gauge that I believe is accurate, but who's to say. If you get what you pay for, then it ought to be dead nuts accurate, but I have never even thought to calibrate it to a known standard.

Was I nice ? Sorry not too helpful, though.

vipernicus42

iTrader: (4)

D'oh...

Oh well, more info in once place.

Jon

sgieldon

Paul has some great information!
I have in the past done some of his recomendations.
Some Good-Some Bad!

Alot depends on final aplication what your trying to accomplish and what you have to work with what you and others have Built.

I'm not sure his Fuel Pressure Guage will work as good on Holley or Weber setups with Complete Fuel Sytem Makeovers as Accurate
as he is Statement Claims.
Not Pessimism-No Experience.
Anyone tried them with a Holley or Weber???

The last thing I want is another Guage to hang on my Pegboard Of Death
Thanks
sgieldon
steve

ddewhurst

With reference to pressure gauges following is some info from www.mcmastercarr.com

I have one of these 0 to 5psi gauges for fuel for a 12A carb. I regulate to 2 psi & the accuracy of the gauge is + or - 1.5% full scale which for accuracy is: 2psi x .015 = .03 psi
The accuracy of my gauge is + or - .03 psi........ + or - 3/100 of a psi

IIRC some gauges are tolerance accross the full scale & some are closer accuracy accross the mid part of the scale with less accuracy at either end of the scale. Go look around within mcmastercarr.com


Low Pressure Steel-Case Diaphragm Gauges— ±1.5% Full-Scale Accuracy (Not Graded)
• Case: Black painted
• Designed to measure very low pressure
• General service phosphor-bronze diaphragm
• Connection: 1/4" NPT male brass
• Lens Material: Acrylic
• Temperature Range:
Ambient and Process: 0° to 140° F

Center Back Connection

Available Pressure Ranges

Pressure Figure Grad.

Range Intervals Marks



psi
0-3 0.5 0.05

0-5 1 0.1

0-10 2 0.2

sgieldon

Per Racing Beats Instructions and phone conversatios with them!
They State to Plug the Fuel Return Line w/ there Holley or Weber Carbs.

I have read in past post about using a Jet in that line.
I have not tied that setup yet.

What size Jet do I use?
Thanks
sgieldon
steve

Tom

Had the same problem when I ran 45 DCOE in my 12A stocker. The used Weber carb came with a dual line banjo (inlet and return) and I had fuel readings all over the frekin' place.

Switched to a single inlet banjo (no return). Absolutely no problems.

Try capping the bitch first and see how it responds. Worst thing that could happen is it floods.

vipernicus42

iTrader: (4)

Dude... The http://www.mcmaster.com/ place is awesome

"Catalog page 515" is what you're looking for, or just search for "Low Pressure Steel-Case Diaphragm Gauges".

If I couldn't get Paul Yaw's (with the snubber because I'm running a 6psi pump) then I would definitely get one there. Prices are similar.

The only question is, if I get the 0-5psi gauge with the centre back connector, would this gauge mount in-line off a T valve, or would it mount on the second outlet of my FPR?

Jon

Tom

I think you can mount them either way. I run my holley guage right off the FPR, but I've also got a spare in line connector lickewacky has shown in his photo.

Use an NPT fitting on the FPR, connect a fuel line, attach the guage, clamp the ends and tape the sucker to your windshield. Once it's dialed in, you should be good to go.

Siraniko

iTrader: (13)

There are 2 types of Holley FPR: 1-4 and 5-9.
Also, I experienced a problem with the mallory 4309. I was unable to set the pressure below 9 PSI using a MSD F/I pump in the FB. Per Robert @ RotaryShack, the older mallory were not designed for carb application. The newer ones are. So instead of buying a new one, I added a return to the my old Holley FPR. I works fine with my IDA and no fuel starvation since I also installed a webber fuel jet in the return to control the flow back to the tank

sgieldon

Thankyou for everyones response to this Thread.
As usual we are all up to the plate when asked too.

I recieved my New and Supposed= Up Yo Date Mallory 1-15psi yesterday.
Ran it with 2ft tube taped to the windshield and it held Steady @5-6psi.
Exactly what Racing Beat said to run at.
Re-Hooked to the FPR and @ Idle 900rpm,2000-4000-6000-7500 held @ 6psi of course no load, but that's why I did the windshield test 1st.

Damn Good Liquid Filled Gauge for $30.99US

The Tech @ Mallory had told me that the Mallory Pump and FPR that I run wired direct is supposed to make up for demand to keep the fuel flowing within a 1-1.5psi variance.
Well he is Right-On.

Mar3 i'm sure you new that, but was waiting for me to find out on my own.

Anyhew: Problem fixed and Thanks again every RotorHead.
sgieldon
steve
P.S. Mr. Grimes;
The reason I name dropped you is, in reading your Past Threads I have done some Mod's that you have written about with alot of Success. Your input is always helpful!