Fuel line???

sixbanger · 08-19-2005, 06:19 AM

How important is it to have all the same size gas line?
Yesterday I was under the front of my car and saw the exit line from the tank and saw that where it goes to the fuel filter it got smaller.Then it went to the fuel pump (after market) and stays the same till it goes to the metal line to the engine and to smaller rubber hose then the same going to the metal line going back to the tank.

I'm trying to get some PMO'S to work on this 69 911 with S spec's.
I started the car and it ran for a while and I was adjusting the timming and it seemed it ran like crap after warming up then a while later it would hardly run at all then it wouldn't even start.So I just pushed it aside to think what may be going on.

I had to remove the return line completely just to get 3-4PSI at the engine bay fuel gauge. The float level looks right now through the float bowl window.

As I increased the engine speed it falls right on it's face.

Thanks in advance

RT.

sixbanger · 08-19-2005, 06:20 AM

Also do I need the spacers under the manifold to keep the heat down?

Kevin Taylor · Kevin Taylor's Garage

BUMP for a brother.

K.T.
1973 911E 2.4 MFI
1983 911 SC
1965 Devin "D" - 1967 912 Power Plant

911pcars · 08-19-2005, 12:32 PM

Will probably need more background info.

For example:
Are you using a fuel pressure regulator?

When you "removed" the return line, does that mean you blocked the return?

What kind of fuel pump?

What kind of fuel filter?

When you work the throttle (engine OFF), does fuel squirt into the throttle bores?

Fuel line ID doesn't make a difference unless it's really small and restrict flow/volume.

How's the compression?
I assume you plugged the injector holes (just checking)
Points adjusted okay? How's the spark? How's the spark to each plug?

Yes, you should use insulators under the carbs.

Sherwood

sixbanger · 08-19-2005, 01:36 PM

NO
yes
Mr Gasket fuel pump 2-4 lb.
Mr Gasket glass see through
Yes it squirts
Plugh are w3sc Bosch
No injector holes
New points.
As for spark, the car starts righr up
Will get the insulators

Ran it again today. Same thing. It's like it wants more gas. I'll check the JETS this weekend.

911pcars · 08-19-2005, 03:38 PM

Is it possible to observe the fuel level while the symptom is occuring?

Sherwood

sixbanger · 08-19-2005, 08:07 PM

I watched today to see just what the fuel pressure was when the engine was given the gas and the gauge just bounced around.I couldn't make sense of just how much pressure I had. It bounced to at least lb down to zero.The needle reads maybe just over 4 lb but when I open it up it just goes all over the place.I saw in the float bowl that the level did drop some but I don't think that it is running low.Could it?If the pump was not keeping up I think this might be a factor. Should I try a larger output pump? Do others block off the return line to the tank? I've heard that this will over time knock the floats off.

RoninLB · 08-19-2005, 08:59 PM

Quote:

Originally posted by sixbanger
I was under the front of my car and saw the exit line from the tank and saw that where it goes to the fuel filter it got smaller.Then it went to the fuel pump (after market)

so you have a fuel filter before the pump? I never liked that idea personally. And you also see the carb fuel level drop by looking into the PMO glass?

Maybe check your pump volume? You could find out the info from the mfg or use Bill V's info for an idea of what your looking for in volume. I might disconnect that filter first and see what currently happens? Then check the volume with the pump feeding fuel from the tank. If ng then confirm it's the pump and not a clogged fuel tank screen/filter.

Also the bouncing gauge on a dead head carb system is from the needle and seat filling the fuel well. It should mostly stabilize at your set psi as you rev the engine with a good fuel feed.

SC vc. Carrera fuel pump

and maybe set up a signature.