Fuel Pressure Isolator

[Stumper]

I installed a Mallory fuel pressure isolator on my car a couple weeks back. I run a dead ended regulator with two lines coming off to feed the carb. I had a tap and a small gauge on the rear bowel line at the regulator and had the pressure set at 7 psi. I left this gage intact to have one in the engine compartment and ran the isolator off a tap on the front bowel line from the regulator. Fuel to one side of the isolator and coolant on the other side into my interior gage. Thought I had the line full of coolant but the interior gage reads a bit over 9 psi while the gage in the compartment still shows 7 psi....:head_smack: Does this mean I still have air in that darn line ???:banghead:

 

[fugly]

usually will read low if there is air as air compresses....likely the small guage is inaccurate especially if it is fluid filled

 

[Stumper]

That's the concept I was wrestling with. Air compresses easier than liquid but also expands more and faster, with heat. But in your experiance with these things trapped air would give a lowered reading eh?
Hummm, I guess I should check with a test gage to be sure. My initial set up used the interior gage - direct fed from the fuel line when I picked the car up!! I had it set to around 7 psi. When I put the little gage (not filled) on it also read 7 psi so I has "assumed" it was correct. I hate to think I've been running 9 psi all this time. I have a test gage, maybe I can check that today and see what it shows. My luck it will read 8 psi ........
Thanks Fugly

 

[Stumper]

Well, I put a test gage on the port today. The small gage that was on the port was reading 7psi while the interior gage was up a bit over 9 psi at the start. The test gage read around 9 psi, so know i know the little one is crap. I adjusted the pressure down to 7 psi on the test gage - but the interior only came down to about 7.8 psi....... Still running higher inside than the actual, albeit not as much.

 

[fugly]

Have you tried warming the carup?sometimes they read a bit high cold-if the little guage is liquid filled, drill a small hole and bleed the fluid-it will probably read right then

 

[Stumper]

Yea, these measurements were with it warmed up. The little gage is not liquid filled - just a cheap Holley from the parts store. I'll get another one at some point. I'm more interested in getting the interior gage reading correctly. Right not it reads 0.8 psi more than the test gage did. It is also not a liquid filled gage - Autometer mechanical.

 

[fugly]

you could try topping off the antifreeze in the interior line as per the instructions....does the guage go to zero when you shut it off after a bit?

 

[Bbody540]

Hey! nice car stumper

 

[Stumper]

I see you like these ugly ducklings too?

 

[Stumper]

you could try topping off the antifreeze in the interior line as per the instructions....does the guage go to zero when you shut it off after a bit?

The interior gage has a tendency to stay about a couple pounds of pressure even after it gets shut down (alarm 1). The others went right to zero after the pump goes off. This one even shows a half pound or so after it sits for awhile (alarm 2) - it nevers falls back all the way to the stop peg... Maybe it's bad too??

 

[SUPERSTOCKRACER]

If you want to run a fuel pressure gauge inside the car just get a electric one otherwise just mount the mechanical one outside on the cowl.

I run a electric one inside my dodge coronet

 

[Stumper]

Yea, that would be an option. Never had an electric fuel pressure gage before. Do you set it against a standard mechanical or?

 

[SUPERSTOCKRACER]

Yea, that would be an option. Never had an electric fuel pressure gage before. Do you set it against a standard mechanical or?

I have a mechanical gauge in my engine compartment.I like to set my regulator from that gauge and then read my interior one which is usually very close.

 

[Stumper]

I have a mechanical just off the regulator also for making adjustments. This is the one that will need the new gage now .... I've been trying to get the interior mechanical working properly too but it seems to read about 0.8 psi higher than the test gage I used on the regulator. I guess maybe if that gage is also screwed up and I need to get anther for inside maybe I'll just go electrical and eliminate all this headache with the isolator.

 

[Bbody540]

I see you like these ugly ducklings too?

Yep, and when I'm at the track you wouldn't belive the comment's I get. the people love these car's or they hate them!

 

[fugly]

If it is consistently .8 high, I would leave it alone- mechanical is always better when possible- 1 less thing to go wrong...

 

[SUPERSTOCKRACER]

Yep, and when I'm at the track you wouldn't belive the comment's I get. the people love these car's or they hate them!

The comment I hear the most is that you only have 1 seat.:bootyshake:rotest::werd::foshizzle:

 

[Bbody540]

The comment I hear the most is that you only have 1 seat.:bootyshake:rotest::werd::foshizzle:

only need one seat to race a car:sleepy2:

 

[Stumper]

Yep, and when I'm at the track you wouldn't belive the comment's I get. the people love these car's or they hate them!

I get the same thing all the time - which is a big part of the reason I love these things... The look has really grown on me, long before I bought this one.
On the other hand I don't really care for the 62' Dodge. Pretty neat look alikes - albeit with the extra doors on mine

I used to run those Draglites and the Hoosier QTPs on mine too but recently switched to the Torque Thrusts.

 

[SUPERSTOCKRACER]

Stumper, very nice ride you got there!