Fuel Pulse Damper

ajr2820 · Post by **ajr2820** » 04 Oct 2011, 07:32

Some quick questions:
1. What does it do?
2. How does it work?
3. What are the symptoms of failure and how do I test it?

I am losing fuel pressure when shut down and before I go removing the fuel tank to get to the regulator, I want to be sure to check everything else first.

Post by **misha** » 04 Oct 2011, 16:17

This should answer all of your questions:

fuel damper 850,s,v,c70.pdf: (25.59 KiB) Downloaded 1655 times

FCPEURO · Post by **FCPEURO** » 04 Oct 2011, 16:19

Thanks for the PDF. Learned something new today.

Post by **misha** » 04 Oct 2011, 16:41

ajr2820 wrote:...I am losing fuel pressure when shut down and before I go removing the fuel tank to get to the regulator, I want to be sure to check everything else first.

It could be a bad check valve.The bad news are that it's the part of the fuel pump.In other words,it's integrated in the pump.

Solutions are to simply add a check valve in fuel line or to replace fuel pump.

One other thing that might help would be priming before starting the engine.

Priming:
Turn the key to ignition II.You should hear the fuel pump running for about 2 seconds.When it stops,immediatelly turn the key off and back again to position II.Repeat this procedure 3-4 times before you start the car.On 4th prime,start the car immidiatelly after the fuel pump stops.

This builds the pressure in the fuel rail and the car starts quicker with less cranking.

If this priming helps with starting(usually does),than you will know for sure that your check valve is bad.

Post by **misha** » 04 Oct 2011, 16:43

FCPGroton wrote:Thanks for the PDF. Learned something new today.

Enjoy!

ajr2820 · Post by **ajr2820** » 05 Oct 2011, 05:57

Thanks for the responses. I did not consider putting an inline check valve on the car. That may be the best route for me as the pump still works and is a PITA to replace. Anyone know where I can get one that will suit my needs?

ajr2820 · Post by **ajr2820** » 05 Oct 2011, 06:01

On another note. Is it possible for this damper to cause the loss of fuel pressure I am experiencing? Just want to be sure before I move forward.

Post by **misha** » 05 Oct 2011, 17:30

My understanding is that when fuel pressure damper/regulator fails,the car runs very rich.

Do you have problems ONLY when starting the car or you have problems when you driving the car?