Hello Everyone,

Tomorrow I am going to install an autometer electric fp gauge. I am mounting in to the schraeder valve with the hose kit that geno's sells. With the hose kit and the electric gauge, do I still need a needle valve to cut down the fluctuations? Also, if I do need one, is it ok to mount it after the hose right before the sender? Other than that, the install looks pretty straight forward. Thanks in advance for the help!!

Josh

 

Yes, you should still run a needle valve (snubber). I noticed when installing mine, I still got a rise and fall of the gauge needle of about 8 lbs, but no pulsations. That was before I changed my lift pump and overflow. I have not checked it since to see if it made a difference. (actually I did check it with a mechanical gauge, but not with an electric like the first time I checked it). BTW, mine is a 12 valve.

The advantage of running the valve before the hose is if you ever have a problem, you can shut the flow off at the source, but, I see no reason why you could not run it the way you want to. KD

 

I would want a needle valve, for both reasons above. Anytime you can plumb in a valve early in a line, and not worry about flow restriction, why not do it!

NAPA sells a nice little brass valve that works great.

 

Well, its all in!!! Fuel pressure is 12 @ idle and 5 @ WOT with the comp box on 3x4. Going to be upgrading to a walbro here soon.

Used a needle valve and the needle is as steady as a rock. Pretty easy install except there must have been an air buble in the line because when I first started it up, it was @ 12, then like 30 seconds later it dropped to 2, and stayed there. If I shut it off, then restarted it again, it would go back up to 12 for like 10 seconds then go back down to 2. Bled the line again, now its staying @ 12 and I let it idle for 10 minutes and it didn't change. So hopefully thats all it was and my LP isn't just working intermittently.

Thanks for all the help!!

 

Any idea on a part number for the valve or what I should ask for when I go to put my gauges in? Thanks...

 

Well, went for another drive and it looks like my lp might be toast. It'll be @ 12psi @ idle and between 9 and 11 while driving, but after about 3 or 4 minutes of driving it will drop down to 6 @ idle and about 4 while driving. If I shut the truck off, it will be @ 12 again for 3 or 4 minutes then go back down.

Anyone ever hear of this? Is it possible for the lift pump to run strong, then die down, then all you have to do is restart the truck and it'll work fine again for a few minutes? Seems pretty bizarre to me. Guess its time to upgrade the fuel system.......

The valve I got was part number 6825, it is a 1/4" npt female one end male other end.

 

WH6820 (Weatherhead), the NAPA number is the same (minus the W).

Make sure to get a 1/8" brass close nipple too, if needed.

 

Thanks a million...Sorry about the late reply, forgot which thread I posted the question to.

 

One of my lift pumps did this when it was dieing. I could also gun it to bring fp back up for a couple minutes.

 

I just had the exact same symptoms on a 5k mile old campaign pump. Put in a Holley black and all is back to normal again. Pressures seem a little low and she drops to nothing on initial startup with grid heaters cycling, but I'm going to plumb in a relay as I think the Holley black may draw too much (4amps) for the ECM to handle.

 

I heard the internal relief bypass begins sticking open, causing the lower fuel pressure reading. As the vibrations, fuel flow, etc. change, the bypass can snap shut again, raising pressure. That is why ph4tty could get the pressure up by gunning the motor -- it swung the fuel pressure really low on the pressurized side of the relief.

 

I'd read that here too, however I'm skeptical in my thinking. My understanding was that was on the output of the pump (after the high pressur point) therefore couldn't possibly affect input pressure.

Now that is warm enough for no grid heater action my pressures are very steady, and they weren't with the 5k mile old campaign pump so I'm happy.

It is time to swap out my factory batteries though too, between the fuel psi acting up on grid heater activation, and my volt gauge slipping down slightly should be any day now that my tranny will be acting up. After 6 years, its time though.

 

Hmm. I was talking about the internal relief of the Carter Lift pump sticking open. It is (I read) supposed to allow the pump to continue pumping fuel in a circle when the outlet pressure to the VP44 is too high (roughly 15 psi.) I have never seen a schematic or taken one apart, so I am not sure if that was a bogus explanation or not, but it seemed plausable, since we do not have any other regulators or bypasses from the LP anywhere. I had to set an external pressure regulator to the ballpark fuel pressure I wanted when I installed my Walbro GSL392 two weekends ago, since it would pump up to maximum pressure without one. I don't know what 100 psi to the VP would do, or if it would even make it past the stock filter housing!!

 

See, the way I understood the internal bypass on those was that it was to allow the VP to continue to suck fuel (temporarily) in the event of the pump seizing. The VP has it's own bypass, I don't see why they would need the LP to have one also?

100 PSI to the VP would probably make it impossible to start.