The Downward Spiral

Seems like my motor cranks too long before it starts. Any ideas? 2001 WJ with an V8. No check engine light on, runs fine when started.

tsconver

what happens if you turnthe key on and wait for a minute before starting or turn the key on and wait, then turn it back off and then on and wait and then start? If either of those fixes teh long cranking then you have a bad check valve or bad fuel pump.

The Downward Spiral

I'll check when I am driving home from work. Thanks.

The Downward Spiral

Got in my Jeep today, turned the key on 2 times, waited about 30 seconds and it started right up. So what is a check valve? How do I change it?

WJCraig

you just have to wait about 5 seconds. When you first turn the key, you should hear a quiet "hum". Once that stops, crank it over. Give your fuel pump a chance to feed the engine, before you try to start it.

Later.

tsconver

It should hold pressure to allow for immediate starting, the check valve is intergral to the fuel pump I think and is inteh tank.

this is from the 03 FSM

Use this test in conjunction with the Fuel Pump
Pressure Test and Fuel Pump Capacity Test.
Check Valve Operation: The electric fuel pump
outlet contains a one-way check valve to prevent fuel
flow back into the tank and to maintain fuel supply
line pressure (engine warm) when pump is not operational.
It is also used to keep the fuel supply line
full of gasoline when pump is not operational. After
the vehicle has cooled down, fuel pressure may drop
to 0 psi (cold fluid contracts), but liquid gasoline will
remain in fuel supply line between the check valve
and fuel injectors. Fuel pressure that has
dropped to 0 psi on a cooled down vehicle
(engine off) is a normal condition. When the electric
fuel pump is activated, fuel pressure should
immediately (1–2 seconds) rise to specification.
Abnormally long periods of cranking to restart a
hot engine that has been shut down for a short
period of time may be caused by:
² Fuel pressure bleeding past a fuel injector(s).
² Fuel pressure bleeding past the check valve in
the fuel pump module.

WJCraig

Sorry, I meant after the vehicle as been sitting for a while, not when it was warm. That's a nice little chunk of info you posted there...I guess those FSM's have a useful nugget or two in them!


If you don't mind, could you type out the rest of that manual for us wen you've got a spare few minutes?

Just kidding...


Later.

The Downward Spiral

So I am waayyyy to impatient to wait those extra few seconds before I start the motor. So I did some homework and found this:

SYMPTOM/CONDITION:
The customer may experience a longer than normal engine cranking time prior
to engine start. This condition may be caused by fuel pressure loss due to
a worn sealing ring within the fuel module.
NOTE: QUALITY ANALYSIS HAS REVEALED THAT A WORN SEALING RING IS THE
PRIMARY REASON WHY THE FUEL MODULE IS REPLACED FOR FUEL PRESSURE
LEAK DOWN. IT IS RECOMMENDED THAT THE SEALING RING BE REPLACED
BEFORE A FUEL MODULE ASSEMBLY REPLACEMENT IS ATTEMPTED.

Went to the dealer, they confirmed this, and I had them fix me up with a new sealing ring. Starts right up now, no waiting.

Kyle

Glad you got it taken care of, thanks for reporting back with the fix.