7th Gen Civic fuel pump check valve
03-03-2017
#2
If you think a good mechanic is expensive, try hiring a bad one
Re: 7th Gen Civic fuel pump check valve
There are two in the system. One in the pump, one in the pressure regulator.
Test residual fuel pressure drop rate to determine if there is a problem or not.
Test residual fuel pressure drop rate to determine if there is a problem or not.
03-03-2017
#3
Registered!!
Thread Starter
Join Date: Aug 2013
Location: San Antonio, TX
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 
Re: 7th Gen Civic fuel pump check valve
I know about the fuel pressure regulators. There's in the fuel pump assembly and one on the fuel rail. I'm losing pressure. I'm getting flow back to the tank. I must've missed something when replacing the pump.
03-03-2017
#5
If you think a good mechanic is expensive, try hiring a bad one
Re: 7th Gen Civic fuel pump check valve
The pressure regulator itself acts as a check valve.
It must regulate system pressure at (something like) 40-45 PSI and it does that by bleeding off excess fuel pressure into the tank, but it also must not allow uncontrolled pressure bleed off when below that pressure.
Make sense now?
The system must retain residual fuel pressure long enough that the engine heat does not boil fuel in the engine compartment after shutdown (heat soak), so it needs to retain pressure long enough for the engine to cool, or slowly lower as the engine cools. It WILL eventually drop pressure to zero, but as long as the engine is sufficiently cool by that time it's ok.
It must regulate system pressure at (something like) 40-45 PSI and it does that by bleeding off excess fuel pressure into the tank, but it also must not allow uncontrolled pressure bleed off when below that pressure.
Make sense now?
The system must retain residual fuel pressure long enough that the engine heat does not boil fuel in the engine compartment after shutdown (heat soak), so it needs to retain pressure long enough for the engine to cool, or slowly lower as the engine cools. It WILL eventually drop pressure to zero, but as long as the engine is sufficiently cool by that time it's ok.
03-03-2017
#6
Registered!!
Thread Starter
Join Date: Aug 2013
Location: San Antonio, TX
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: 7th Gen Civic fuel pump check valve
My issue is a long long crank time after I replaced the fuel pump. I've replaced both fuel pressure regulators as well. Still long crank time.
03-03-2017
#7
If you think a good mechanic is expensive, try hiring a bad one
Re: 7th Gen Civic fuel pump check valve
It's possible the filter assembly could be your culprit, have you replaced it?
Sure you got all the O ring connections sealed ?
Sure you got all the O ring connections sealed ?
