# Bubbles in fuel normal?



## BatmanGTO (Jun 18, 2011)

Hi all,
Took the 66 out today and had to get gas, it was just under half tank. Turns out they were out of 93 so I had to go to another station. This car is a PITA to restart. I was a good 10 minutes trying to get it fired again. I finally popped the hood and checked all my connections. While wiggling the fuel line I noticed some bubbles in the fuel filter, didn't think much of it at the time. So I go to the next station, fill up and again, can't keep it running. The first crank it will fire, I can run it for 10 seconds or so, then it just dies. So I try one more time and it won't fire. Then I get to thinking about those bubbles. So I pop the hood and wiggle the fuel lines again, a bunch of bubbles appear in the filter. I keep wiggling until no more bubbles appear. Then she fires right up. SO I get it home, immediately pop the hood and the fuel in the filter is bubbling like crazy. Wiggling the lines makes more bubbles appear.

So is this bubbling normal or is it air in the lines? Can this be coming from a leaky seal back by the tank? Or should I be looking else were?

Temp was only 80* Car was around 200* at the time of restart.


Thanks


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## Instg8ter (Sep 28, 2010)

hey Batman, may be from the rubber lines in your fuel system having micrscopic cracks bleeding air in under pressure i would replace all the rubber lines (there is a small section at the tank sending unit also).


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## 69Goatee (Aug 14, 2009)

Sounds like your fuel pump is sucking air, and loosing its prime and your float bowls are running dry. Do you know what kind of fuel pump you have, electric or mechanical? Either one could have a bad hose or cracked hard line somewhere between it and the tank.


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## BatmanGTO (Jun 18, 2011)

Nice to see you around again Brian, you must be slammed with work!

I have an electric pump from summit racing.

So the bubbles are not normal, all I needed to know. Most the fuel line looks brand new. But there are a few sections where there is old rubber hose, right by the filter.

In this pic you can see the blue line, those are beefy and look new.









This pic you can see the old rubber hose I speak of.


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## chuckha62 (Apr 5, 2010)

Is that your fuel pump sitting right behind the filter, or is that a fuel pressure regulator? If it's your pump, the location may be part of the problem. Fuel pumps are pushers, not pullers. Your pump needs to be low and in the rear of the car near the tank to work properly.If that's a regulator, that may be the source of the air.

Just a thought

Chuck


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## BatmanGTO (Jun 18, 2011)

Yeah, pumps back at the tank.


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## Eric Animal (Oct 28, 2007)

Bat, It could be a loose line at a clamp, or a defective filter. Go over all your clamps and lines...first things first. Also, check the little filter that is in the carb, where the fuel line goes in....E


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## pontiac (Mar 6, 2011)

could be fuel percolation \ vaporizing as well.


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## jetstang (Nov 5, 2008)

Start by changing out that nasty filter and feed lines. It may be clogged, if not, it's old. May be a simple fix.
Very nice looking motor!


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## BatmanGTO (Jun 18, 2011)

Any idea what brand that is (I couldn't find it on Summit or Jegs)? I like the idea of the glass, do you have a better recommendation? Do you mean change all lines from the regulator to the carb?

Thanks!


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## BatmanGTO (Jun 18, 2011)

I think I found it, it is plastic, not glass which is why I didn't see it in the other searches. I just need to find the size now.

Wix Filters 495-33003 - WIX Filters Fuel Filters - Overview - SummitRacing.com


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## jetstang (Nov 5, 2008)

It's just a fuel filter, and not a good one. Take it off, go to autozone and just match it up to one with the same size nipples, 5/16ths or 3/8ths. You can get the glass Spectre one at autozone that you can reuse and clean for under $10. Just the hose between the filter and pressure regulator.
When it doesn't start you need to look in the carb and make sure it's squirting gas from the accelerator pump and does the filter have fuel in it.
Also check your fuel pressure, it should be about 5 psi when the pump is on.


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## BatmanGTO (Jun 18, 2011)

It's about 6 psi and does have fuel in the filter, that is where I noticed the bubbles, was in the fuel that was in the filter.

Let me clairfy the no start. I turn it off, then try to re-start (when warm after driving). It will fire, run for 10-15 seconds and then just die. No amount of feathering will make it attempt to stay running. If I sit for 1-2 minutes I can get it to do exactly the same thing. If I try to start it immediately after that happened it don't fire at all. Both times I wiggled the fuel line until the bubbles stopped then she fired up and stayed running.

I haven't ran it since this, I'll try to get it out today and check the carb.


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## jetstang (Nov 5, 2008)

It's running on the remaining fuel thats in the fuel bowls and not getting new gas. That is why I'm saying to look at the squirt in the carb, no squirt, no gas, get it?? If so, then it's a fuel delivery issue, not carb or ignition. Where is the fuel pump located? Needs to be near the fuel tank and mounted low. The gas is boiling in the lines and evaporating. When you are driving it there is enough flow so the fuel doesn't heat up, when it sits it boils.
I'll put money on it that the fuel pump is too close to the exhaust and getting heatsoaked. Move or insulate the pump, or both. That is the only thing that makes sense with an electric pump. Vapor lock is a common problem with a mechanical pump, because it's near the exhaust, I used to dump water on my pump to cool it when it happened to me.


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## BatmanGTO (Jun 18, 2011)

Thanks, I get it. Just making sure you guys got all the info I could think of

The pump is in the back, here is an old pic I have handy you can kinda see it.


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