Sound found
Thread Starter
Burning Brakes
Joined: Feb 2010
Posts: 1,013
Likes: 2
From: California City Ca
Sound found
I was chasing a knocking sound in my Vett for a while now it’s been tracked down to the Fuel Pump Regulator.
It holds 43 PSI of pressure at Idle But as soon as you turn the engine off it drops to Zero.
It has almost NEW FIC Bosch III 24# injectors and same for the Fuel pump a Walberg 190.
When doing some more reading some are saying the Fuel pump regulator pulse dampener is bad.
That’s fine I ordered one where is it on the car.
It holds 43 PSI of pressure at Idle But as soon as you turn the engine off it drops to Zero.
It has almost NEW FIC Bosch III 24# injectors and same for the Fuel pump a Walberg 190.
When doing some more reading some are saying the Fuel pump regulator pulse dampener is bad.
That’s fine I ordered one where is it on the car.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The "pulsator" is attached to the fuel pump using a couple small sections of rubber hose between the pump and the steel line that runs up through the mounting plate at the top of the gas tank.
With your Walberg pump, there was most likely no pulsator provided. Was there anything in the install instructions that mentioned re-installing the OEM pulsator?
When I replaced the FP in my 87, I never installed the old pulsator and I don't see any difference in how the car runs or any noise from the pump or fuel flow. With a stock setup, pressure should remain in the fuel system for a good couple hours and gradually dropping off.
Try searching this section on "pulsator" to get some more info.
There is also a fuel pressure regulator that sits under the intake plenum in front of the distributor. Has that been replaced?
With your Walberg pump, there was most likely no pulsator provided. Was there anything in the install instructions that mentioned re-installing the OEM pulsator?
When I replaced the FP in my 87, I never installed the old pulsator and I don't see any difference in how the car runs or any noise from the pump or fuel flow. With a stock setup, pressure should remain in the fuel system for a good couple hours and gradually dropping off.
Try searching this section on "pulsator" to get some more info.
There is also a fuel pressure regulator that sits under the intake plenum in front of the distributor. Has that been replaced?
Thread Starter
Burning Brakes
Joined: Feb 2010
Posts: 1,013
Likes: 2
From: California City Ca
No I have not replaced the Fuel pressure reglulator I was going to try the pulsator by thinking about it I did not start getting this sound until after I put the new fuel pump in the car.
The "pulsator" is attached to the fuel pump using a couple small sections of rubber hose between the pump and the steel line that runs up through the mounting plate at the top of the gas tank.
With your Walberg pump, there was most likely no pulsator provided. Was there anything in the install instructions that mentioned re-installing the OEM pulsator?
When I replaced the FP in my 87, I never installed the old pulsator and I don't see any difference in how the car runs or any noise from the pump or fuel flow. With a stock setup, pressure should remain in the fuel system for a good couple hours and gradually dropping off.
Try searching this section on "pulsator" to get some more info.
There is also a fuel pressure regulator that sits under the intake plenum in front of the distributor. Has that been replaced?
With your Walberg pump, there was most likely no pulsator provided. Was there anything in the install instructions that mentioned re-installing the OEM pulsator?
When I replaced the FP in my 87, I never installed the old pulsator and I don't see any difference in how the car runs or any noise from the pump or fuel flow. With a stock setup, pressure should remain in the fuel system for a good couple hours and gradually dropping off.
Try searching this section on "pulsator" to get some more info.
There is also a fuel pressure regulator that sits under the intake plenum in front of the distributor. Has that been replaced?
Thread Starter
Burning Brakes
Joined: Feb 2010
Posts: 1,013
Likes: 2
From: California City Ca
When I got home from work today my new pulse dampener was at the door
It took about 30 minutes to install it fired the car back up Idove it to work today it seems much better.
I find out more after the car sits and I can start it cold thats when it made the noise the worse.
But so far so good.
It took about 30 minutes to install it fired the car back up Idove it to work today it seems much better.
I find out more after the car sits and I can start it cold thats when it made the noise the worse.
But so far so good.
Last edited by Marv02; Mar 9, 2012 at 08:48 PM.
Thread Starter
Burning Brakes
Joined: Feb 2010
Posts: 1,013
Likes: 2
From: California City Ca
Did a cold start up this morning much much bettter there still a little noise but unles you were purpose listening for it you never notice it.
I going to order a new FPR diaphragm and see if this will completely get rid of all fuel rail noise.
I going to order a new FPR diaphragm and see if this will completely get rid of all fuel rail noise.
