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-   -   Thoughts on Why a Long Crank Till Start (http://www.wranglerforum.com/f210/thoughts-on-why-a-long-crank-till-start-191486.html)

Johnrmclean 10-05-2012 08:47 AM

Thoughts on Why a Long Crank Till Start
 
My 4L ..5 spd likes to crank a long time before it fires up. Overall it runs great.
190,000 miles, no oil usage, no leaks , great oil pressure. Plugs look good but did not check the gap.
Anyone have any thoughts on the reason for the long crank?

c_goodnow 10-05-2012 09:04 AM

Try cycling the key on and off a couple times before starting...leaving it at on for a couple seconds each time, then try starting.

The fuel pump doesn't run continuously, it cycles on for about three seconds before starting to build pressure, then it stops.

There's a check valve type thingy in your fuel line to keep fuel from running back to the tank, if that's failed you won't have fuel to your injectors immediately.

Johnrmclean 10-05-2012 11:00 AM

Quote:

Originally Posted by c_goodnow (Post 2863605)
Try cycling the key on and off a couple times before starting...leaving it at on for a couple seconds each time, then try starting.

The fuel pump doesn't run continuously, it cycles on for about three seconds before starting to build pressure, then it stops.

There's a check valve type thingy in your fuel line to keep fuel from running back to the tank, if that's failed you won't have fuel to your injectors immediately.



Where is the check valve thingy located??

catfish33 10-05-2012 11:04 AM

FPR (Fuel Pressure Regulator) on top of the Fuel Pump.

Jerry Bransford 10-05-2012 11:36 AM

Yep, when the valve inside the FPR starts leaking, it allows gasoline that is supposed to stay in the engine's fuel rail for fast starts to instead drain down and back into the gas tank. That extra time to get the engine started is how long it takes for the fuel pump to get fuel back up to the fuel rail that the fuel injectors plug into.

Johnrmclean 10-05-2012 01:51 PM

Quote:

Originally Posted by c_goodnow (Post 2863605)
Try cycling the key on and off a couple times before starting...leaving it at on for a couple seconds each time, then try starting.

The fuel pump doesn't run continuously, it cycles on for about three seconds before starting to build pressure, then it stops.

There's a check valve type thingy in your fuel line to keep fuel from running back to the tank, if that's failed you won't have fuel to your injectors immediately.

yep that worked great ..started right up first crank :punk:


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