Fuel Injectors?
 

2001 crown vic 4.6...suspect fuel injectors are leaking fuel into the
cylinders when sitting. How do i go about checking this problem?

Fuel Injectors?
 

John P. wrote:
> 2001 crown vic 4.6...suspect fuel injectors are leaking fuel into the
> cylinders when sitting. How do i go about checking this problem?

1. Sniff for gasoline at the intake after the engine has been turned
off
for a minute.

2. Look at the injector signal pulse width while the engine runs.
Leaky
injectors will cause the pulses to be narrower than usual because the
computer will try to compensate for excessive fuel delivery by opening
the injectors less. Any good mechanic can read the computer output
and will know when the pulses aren't right.

3. Hook up a fuel pressure guage and see how fast the pressure drops
as the car is parked.

4. Pull the injectors, reconnect them to the fuel rail, and look for
drips
while the system is pressurized.

Don't try #4 except as a last resort, and I doubt you have a leaking
injector but more likely a problem with the pressure regulator or a
check valve. If the problem is just gas fumes, check the charcoal
canister and its plumbing and valves. Get a Ford or Mitchell manual
and follow its instructions before replacing parts. For fuel-computer-
emissions systems you want these books and not Chilton/Haynes
crap.

Fuel Injectors?
 

What makes you suspect that the injectors are leaking down when
sitting?

John P. wrote:
> 2001 crown vic 4.6...suspect fuel injectors are leaking fuel into the
> cylinders when sitting. How do i go about checking this problem?

Fuel Injectors?
 

Ken wrote:
> What makes you suspect that the injectors are leaking down when
> sitting?


By playing detective i have concluded to 2 possiablity's for
causing my hard morning starts, but fine starts for the rest of the
day...replaced air idle control valve, fuel pump is in good working
order, so its either the fuel distributer, or a leaky injecter. So in
the morning its a hard start to refill the fuel line, and then after
starting it idles very high for an abnormal amount of time, due to the
fact the extra fuel to burn off from leaking in the cylinder over
night..any ideas/feedback?

Fuel Injectors?
 

The abnormally high idle you state is not the result of a leaky injector
causing the engine to burn off the excess fuel leaked into the engine.
The engine would burn all that fuel at start-up, and possibly give you
a long-start at start-up. [basically, flooded]. Also, an injector with
a worn or open pintle will bleed pressure out of the immediate fuel
line. Again, a delay in start-up.

A leaky injector won't spray as well as needed, and the resulting high
idle is PCM compensation. As stated above, a fuel-pressure check of the
injectors is a good place to start. Caveat> usually best left to pay a
shop for the test.


--
Knifeblade_03
------------------------------------------------------------------------
Knifeblade_03's Profile: http://www.automotiveforums.com/vbul...?userid=262826
View this thread: http://www.automotiveforums.com/vbul...d.php?t=614956

http://www.automotiveforums.com

Fuel Injectors?
 

Some more questions to narrow down.
Is all the maintenance up to date:
- Fuel filter
- Air filter
- Induction Service
- Fuel Injection Service
- O2 sensors
- Ignition Service
Has the car ever run out of gas?
Is the check engine light on?
What are the emissions readings when connected to OBDII?

There are many factors that can affect the cold start scenario you are
experiencing. It is very possible to spend more money than necessary
by throwing parts at it. It could be a bad sensor, a clogged filter, a
failing pump, a leaking injector, a loose gas cap, moisture somewhere
in the ignition system. A scanner could point you in the right
direction. Could also point you in more than one right/wrong direction.
Have seen this all too often when the local parts house does a scan
and provides the codes for a DIY'er who then buys all the parts needed
to fix all the codes when it may have only been one of the codes
affecting the rest enough to come on.

Knifeblade_03 wrote:
> The abnormally high idle you state is not the result of a leaky injector
> causing the engine to burn off the excess fuel leaked into the engine.
> The engine would burn all that fuel at start-up, and possibly give you
> a long-start at start-up. [basically, flooded]. Also, an injector with
> a worn or open pintle will bleed pressure out of the immediate fuel
> line. Again, a delay in start-up.
>
> A leaky injector won't spray as well as needed, and the resulting high
> idle is PCM compensation. As stated above, a fuel-pressure check of the
> injectors is a good place to start. Caveat> usually best left to pay a
> shop for the test.
>
>
> --
> Knifeblade_03
> ------------------------------------------------------------------------
> Knifeblade_03's Profile: http://www.automotiveforums.com/vbul...?userid=262826
> View this thread: http://www.automotiveforums.com/vbul...d.php?t=614956
>
> http://www.automotiveforums.com

Fuel Injectors?
 

Everythign is deinfitly up to date, after it was given to me by the
police department, i got ALL fluids flushed, new air/fuel filters.
Cleaned and serviced all electrical connections. So i am stumped you
are right I am a big DIYer but i think i should leave the detective
work to the dealer.