Midnite

Your theory about the grid heaters is an easy one to check by pulling the relay, but I can guarantee you there's no way your grid heaters are going to cause your FASS to go from a normal 15-16 psi to suddenly start cranking out 20-30 psi, or drop down to single digits.

Any time you have a gauge giving you strange readings, the first thing to do is check the readings. You need to get a mechanical fuel pressure gauge hooked up. If that still shows fluctuating readings, then proceed from there.

high bid

Is there a prefilter for the FASS or possibly a screen inside the pump? W/out sufficient psi (>5 or so)100% of the time you're killing the VP. I'd do like mentioned above and install a mech gauge to be 100% sure of your inlet psi as it's not worth the risk of another VP.

Dhughe...even w/the holley you exp this, I have had great luck w/mine?

dhughe2

Yes, and it just started recently. It was pretty rock solid. This morning when I went out to start it, the normal fp bumb brought the pressure up to 1 psi. The pump sounded cold and labored. So I bumped the starter to listen to see what happens when it runs without the grid heaters cycling. The output was 10 psi without the engine running. When I started it, it was 5-6 psi while the grids were drawing, and 9 when they cycled off.

Smokin'02

I am going to try to pull the grid heater relay.

The fuel pressure stays constant on warm days, however, cold mornings when the Wait to Start light stays on more than its normal 3 seconds the pump def. fluctuates more.


Just a thought, can switching the hot wire from the fass to the passenger side battery help at all?
This would allow the FASS to pull from a fresh battery.

Tate

Unless your two batteries are isolated from each other, you're pulling from both batteries.

infidel

To disable the grid heaters for diagnosis is very easy.
Just pull one of the small wires off each relay almost under the battery.
Doesn't matter which wire.

Smokin'02

Okay guys, I disconnected my grid heater, cleaned up batteries +terminals, then replaced the fass connections on the battery.

Problem not solved .

My next step is to install a mechanical fuel pump as well as put a new filter on my fass.


However, the reason I believe its not the gauge is because the pressure fluctuates depending on how I'm driving it. For example when I’m on the throttle it will drop and when I'm off the throttle it will rise.

Do you think its time to call FASS?

high bid

Does anyone know if there is a screen filter inside the FASS?

rebal

sounds like maybe the armature in the fass is dragging and when its warm it settles down seen starters run that way
do you live in salt country? could be corrosion creeping in to the fass motor

Tate

You're willing to buy a mech. lift pump, but not buy a $20 mech gauge to confirm it?

A bad electronic gauge will still fluctuate, it just won't be accurate. My 100 psi gauge in my 12v was acting funky, but would still give semi accurate readings, and then be totally out in a little bit. It would still rise an fall with throttle input like it did on day one. But now it just sits at 6 psi, all the time.

Smokin'02

My next step is to buy a mechanical fuel pressure gauge.

What type would you recommend? Where is the best place to purchase one?

I called fass to see if they had any ideas and ended up leaving a message.

Im in ohio. No salt water. Just salt from the road.