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?
Reply to
John P.
Loading thread data ...

  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.

Reply to
manny

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?

Reply to
John P.

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.

Reply to
Knifeblade_03

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 experienc> The abnormally high idle you state is not the result of a leaky injector

formatting link
View this thread:
formatting link

Reply to
Ken

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.

Reply to
John P.

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.