fuel pressure specs?

On 10/21/2011 8:35 PM, DougW wrote:
> DougW wrote:

> (little bitty leaks can also be dribbling injectors).
>

Often dribbling injectors will give a hard start because of flooding
issues.

--
I'm never going to grow up.

"Will Honea" wrote in message ...

DougW wrote:

> Another test for a bad reg is to just watch the fuel rail pressure
> after priming/running the pump. If it falls then the reg is leaking
> (little bitty leaks can also be dribbling injectors).

And that can be a slooowww drop - I can't put my eyeball on the spec right
now but my somewhat frail memory says that (assuming the proper 31 PSI
pressure to start with) the limit is 19 PSI after something like 10-15
minutes. My 88 I6 will hold 10+ PSI overnight!

--
WHonea

--- Posted via news://freenews.netfront.net/ - Complaints to
---


Interesting happening while I was testing. I had the shutoff valve
installed in the return line and the engine running. I disconnected the end
of the shut off downstream from the valve to take a fuel sample. When I put
the end of the hose in a jar and opened the valve, I had no fuel flow.
Looks like the regulator has been dead-heading the pump all along. This
would explain the no jump in pressure when disconnecting the vac line
result.

Another thing that I've seen cause low pressure and bleed off is the little
rubber coupling between the pump and the sender splitting. The pump in this
thing is just over 2 years old, an AutoZone pump I installed right before we
went on vacation because they're the only ones that had it in stock that
particular day. The Jeep is still driveable the way it is, so I'm gonna be
a bit more picky about the quality of the part I use this time.

On Sun, 23 Oct 2011 06:04:33 -0500, "Old Crow" >
wrote:

>
>
>"Will Honea" wrote in message ...
>
>DougW wrote:
>
>> Another test for a bad reg is to just watch the fuel rail pressure
>> after priming/running the pump. If it falls then the reg is leaking
>> (little bitty leaks can also be dribbling injectors).
>
>And that can be a slooowww drop - I can't put my eyeball on the spec right
>now but my somewhat frail memory says that (assuming the proper 31 PSI
>pressure to start with) the limit is 19 PSI after something like 10-15
>minutes. My 88 I6 will hold 10+ PSI overnight!
>
>--
>WHonea
>
>--- Posted via news://freenews.netfront.net/ - Complaints to
---
>
>
>Interesting happening while I was testing. I had the shutoff valve
>installed in the return line and the engine running. I disconnected the end
>of the shut off downstream from the valve to take a fuel sample. When I put
>the end of the hose in a jar and opened the valve, I had no fuel flow.
>Looks like the regulator has been dead-heading the pump all along. This
>would explain the no jump in pressure when disconnecting the vac line
>result.

What you're seeing would be expected. With a 31psi regulator, it's not
going to bypass if there's less than that available from the pump.

>
>Another thing that I've seen cause low pressure and bleed off is the little
>rubber coupling between the pump and the sender splitting. The pump in this
>thing is just over 2 years old, an AutoZone pump I installed right before we
>went on vacation because they're the only ones that had it in stock that
>particular day. The Jeep is still driveable the way it is, so I'm gonna be
>a bit more picky about the quality of the part I use this time.