Question: Sound found

[Marv02]

I was chasing a knocking sound in my Vett for a while now it’sbeen tracked down to the Fuel Pump Regulator.

It holds 43 PSI of pressure at Idle But as soon as you turnthe engine off it drops to Zero.

It has almost NEW FIC Bosch III 24# injectors and same forthe Fuel pump a Walberg 190.

When doing some more reading some are saying the Fuel pump regulatorpulse dampener is bad.

That’s fine I ordered one where is it on the car.

 

[Marv02]

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.

 

[Marv02]

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.

 

[boomdriver]

A pulse dampener may help but there will always be 8 injectors ticking. They may be semi quiet today but they will tic tomorrow...they all do to some extent. Thats normal. Its a mechanical piece that moves and responds to pressure. Its gets bumped back and forth...so it makes a noise.

The regulator...thats pointless. A diaphram is either torn or good. Its the end plate and spring that matter. If they are in good shape and the correct part then there is little that can be done about any noise thats just a response to its moving...IMO. Not worth loosing sleep over.

 

[Marv02]

It helped out a lot it made a very loud knock before with the old PR during cold start up and was not as bad when warm but now it sound almost normal now.

 

[Marv02]

The noise is back.
I am going to delete the 9th injector and see if this helps like I said before it only makes the noise when it is cold start up.

 

[Marv02]

I pulled the cap NO hitting at all the rotor seen better days I change that
I also pulled the distributor out and checked the end play it's at .017.
The Composite distributor gear is showing wear about half the teeth are worn though already with 7000 miles on it sounds funny to me also the lower 3/4 of the gear is worn more towarded the top of the gear.
I using the stock 1986 distributor with a composite gear is this my issues.

 

[Marv02]

I just ordered a OEM GM melonized distributor gear.
When I built the motor others said the composite gear was the way to go now I reading GM saying for a LT4-Hotcam go with the melonized gear set.
I going to give this a try and see how this gear holds up compaired to the high dollar composite gear.
The OEM is half he price of the composite gear set.
With any luck this where the noise is comming from.

 

[boomdriver]

if that gear was worn down after only 7000 miles...yeah, sumthins not right. Hope this new part fixes it. You've been rebuilding this rebuild for a while now... !
Hell, with the price of fuel maybe pushin it will be cheaper !:eyerole

 

[Marv02]

Swapped the gear out fired the car up the noise still there.
I dont want to pull the motor again.
I just dont get it.
After the car is good and warm no noise.
I went to McDee's drive though on the way to work this morning you could hear the knocking noise very well as it echoed off the wall next to me.

 

[Marv02]

Question I know the pushrods are a little bit on the longside when rolling the motor over and checking for patter wear on the valve stemtip it not completely center it on more the exhaust side more than center Iusing the stock length push rods 7.195

Do you think this could be the problem making the noise?