Mech fuel pressure

madmikeismad

madmikeismad

So mad
Joined
Dec 19, 2009
Messages
14,347
Is it necessary to use coolant between isolator and gauge, or will just air read the same?

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Air will not allow it to work correctly. The coolant is not flammable, that's why its used inside the vehicle.
 
stlcummins said:
Air will not allow it to work correctly. The coolant is not flammable, that's why its used inside the vehicle.
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I thought it was used instead water or diesel to keep the line from freezing in winter. Not flammable makes more sense though LOL

How in the world do you get coolant to fill that tiny little line? Suck it through? Needle?

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That sir I don't know, I always said phuck it and didn't use an isolater. Hahahahahaha!
 
stlcummins said:
That sir I don't know, I always said phuck it and didn't use an isolater. Hahahahahaha!
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Haha. Since there's gaurenteed to be a little air bubble in the end of the line at the gauge, will it throw the gauge off enough to worry?

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Not enuff that has ever caused me any problems. Even on dedicated nitrous systems for the drag cars I've worked on for 20 yrs.
 
stlcummins said:
Word yo.
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**** it. I give up. There is no way to get the 12 inches of air out of the line. I've even tried sucking it through and plugging the end to keep air from getting in. All that accomplished was making my mouth taste like **** and probably taking 5 years off my life. Im just gonna take that snubber diaphram **** out and run a needle valve.

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Pull extra guage line through the housing so you can hang the guage just outside the truck. Then get it on the guage a bit loose and start the truck. It will pump the air out quickly so be ready to get some on ya. Snug it up tight, retract the slack, and be done.
 
I pushed the diaphragm down inside the isolator and filled it. Hooked the line up pressurized it pinched the line off just above the isolator and repeat until it came out the gauge end of the line.
 
Also the needle valve is easily found at homedepot if you have one. Turn that thing all the way closed, then open it about 1/32+ or a turn. Fine tune from there, but it will pulse no matter what. Mine bounces about 7psi at idle, but under throttle there is very little pulse.
 
Ridemywideglide said:
Pull extra guage line through the housing so you can hang the guage just outside the truck. Then get it on the guage a bit loose and start the truck. It will pump the air out quickly so be ready to get some on ya. Snug it up tight, retract the slack, and be done.
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It only pushes about 10in of volume. Then when you cut pressure it just sucks more air in. I tried letting it vacuum coolant back in but its too thick and diaphram ain't strong enough.

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Ridemywideglide said:
Also the needle valve is easily found at homedepot if you have one. Turn that thing all the way closed, then open it about 1/32+ or a turn. Fine tune from there, but it will pulse no matter what. Mine bounces about 7psi at idle, but under throttle there is very little pulse.
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Yeah, tried using the old one but its the wrong size fittings. And of course no one in town sells fittings so im going to have to wait until I drive through a town big enough to have a plumbing store.

Anyone need an isolater? LOL

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madmikeismad said:
It only pushes about 10in of volume. Then when you cut pressure it just sucks more air in. I tried letting it vacuum coolant back in but its too thick and diaphram ain't strong enough.

Sent from my phone.
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Don't cut pressure, that's the idea. Get it all assembled and close to tight on the guage, then start the truck and let some fuel run out while your tightening the guage fitting down. Once it's tight, there should be no vaccuum allowed to pull through and suck fuel back.

Where are you tapping off the fuel system to get the pressure feed? I put the valve right on top of my stock filter mount.

on edit: All the posts from me are regarding NOT using an isolator.. LOL.. Maybe your trying my logic on the isolator. I've never used one so I have no idea how to set one up. Never saw the need.
 
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Nope, isolaters suck.:banned:
madmikeismad said:
Yeah, tried using the old one but its the wrong size fittings. And of course no one in town sells fittings so im going to have to wait until I drive through a town big enough to have a plumbing store.

Anyone need an isolater? LOL

Sent from my phone.
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Ok I found a lowes they built since the last time I was home. With enough reducers I was able to get a ball valve and make it work LOL.

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