Fuel Pump Starvation?

[jhorton3]

I now think the issue with rough running is fuel starvation. Here's the setup: New fuel tank, metal fuel filter, Facet fuel pump, glass fuel filter at the carbs, going into 2 HS2 carbs with the jet adjusting nut turned 12 flats.

Here's what happens: I turned the key to the run
position and the fuel pump starts ticking...loudly.
Before it would quiet down when there was fuel
delivered to the carbs, which was usually an indicated
by the glass fuel filter being filled. Now it never
quiets down and the glass filter doesn't fill. There
is some fuel being delivered as I can see it flow
through, but not like I think it should. Driving she's
shuttering under load and that fuel pump is still
ticking loud like it's not building pressure with
enough fuel.

So when I get back from church I'll pull the filter on
the pump side and see if that improves things. If that
doesn't where to next?

 

[jlaird]

Check for a stuck float valve as well.

 

[mccalebr]

Jim, when I pulled off the home grown FI unit from the TR3 this sping and replaced it with SUs, I also replaced the higher volume Holley pump with the square one (from Auto Zone), I believe it is the same pump (Facet) you have.

When I now start the TR:

1) Ignition switch moved to run, starter button NOT depressed - loud ticking, quickly at first then slightly slows, the ALMOST BUT NOT QUITE quiet (there's still a sight ticking); if you watch this under the hood you will see the small glass prefilter (mounted horizontally), just before the carbs, fill to 1/2 to 2/3 full.

2) After the ticking quietens I then hit the starter button; the ticking may continue or increase, but you can't hear it over the engine and exhaust.

I believe I would exchange the pump for another; I've read on the boards of an occasional Facet that is bad right out of the box and exhibits the same characteristics that you describe.

Just for information sake, Summit carries the small Holley pump (HLY-12-801-1) that delivers 7 PSI/97 GPH. That is still too high so the pump must be used with a regulator; the low pressure unit from Holley (HLY-12-804) delivers 1-4 PSI and is perfect. This is NOT an inexpensive solution...$103 and $27 respectively when compared to the Facet at <$40. If you do decide to go with the Holley (I am doing so on the Spridget) you can recognize both the pump and regulator easily by the red trim. The high pressure units are trimmed in blue.

Hope this helps,

Ray

 

[Healeysince59]

I had a Facet on a Jag that did the same thing. When I first installed it it was noisey untill it picked up fuel then got a lot quieter. Then one day it sterted getting noisey intermittently. I read about similar problems others were having so I pulled it and installed a stock SU.

Several things could be causing your problem. A leak between the tank and the pump and you're sucking air. A block in the line, maybe the filter. A bad fuel pump. Any of these things could cause the vapor-lock like symptoms that you seem to be having. With all the new parts you have, I would suspect the pump.

Marv J

 

[Brian_C]

If that metal filter is between the pump and the tank, I'd start there. Sounds like the pump is struggling for fuel.

If the car runs fine for a little while and then bogs down I'd certainly say it's the filter. i.e. runs fine around the neighborhood and bogs when you try to push the the speed higher.

If it still runs bad without the metal filter, then it sounds like you have a pump issue.

If your metal filter is gunked up, like mine was, you may want to look at cleaning or replacing the tank.

Brian

 

[jhorton3]

Thanks for the input guys. This pump has been odd. It's a square Facet. It's always had moments where it would just tick loudly no matter what. Before it would quiet down as mentioned when the key was turned and pressure built, but not any more. It made this kind of noise once before when the fuel gauge didn't read right and I ran out of gas. That's been a couple of months ago though.

I'll start by removing the filter before the pump and make a straight connection from tank to pump. If I still have the issue then I'll see about getting one of the low pressure Holley units Ray mentioned.

For a while I've had to run the jet adjusting nuts on the carbs way past 12 flats. 12-14 I could understand, but that's too lean for mine, and wonder (more like hope) that the fuel pump craziness is the cause. 12 to 14 is too lean. I've had to run 18-20 flats and it still acts up. I'll keep a post of progress (or lack thereof).

 

[Sarastro]

First of all, you know you're not getting enough fuel to the carbs, so whatever else might be wrong, it makes sense to solve the fuel-supply problem before worrying about other things that may or may not be a problem.

The Facets do make noise when they're dry. Mine gets noisy occasionally, which I attribute to the occasional fuel-vapor bubble. Most of the time it's quiet though, so if yours is noisy all the time, it seems almost a certainty that something is plugged between the tank and pump. Most likely place is in the filter. If this is clean, and there are no obstructions in the line from the tank, I'd agree with Ray that it may just be a bad pump.

Second, I've found that the Facet pump doesn't do a good job of forcing fuel through a conventional filter at the carb input. But, if you have a good filter at the pump input, I have a hard time seeing the need for one at the carbs too. If there were no problems with it, it might seem like good insurance. But, when I tried it, it was just too much of a restriction, so now I'm running with just the filter on the pump input.