2017 JK Unlimited Hard Start When Sitting

Jax Sisson

New member
Hi there, I have been experiencing a hard start after my Jeep has been sitting for anything over an hour. It sort of cranks and sputters till it eventually starts (throttle helps a lot). Once started it idles and drives perfect. I just replaced the seals and oil pressure sensor in my oil filter housing. Also did a fuel injector due to a misfire and then the intake manifold gaskets. When done I had to blead the cooling system for which I had to disconnect the throttle body. So far no leaks. The weird thing is the first time it started perfectly. Never did this before the job. Leaving the key in the run position before starting doesn't help at all. Tried a computer reset. Any Ideas?
 
my guess is the fuel rail is losing pressure. double check the fuel injector you replaced, it may be bad.

I'd also remove the fuel line into the fuel rail, run it into a container and have someone turn the key to run the pump to make sure it works.

If the pump is good, reconnect it to the rail and have your helper start it up while you look at the fuel rail for any leaks.

Another option is to let it run until it smooths out, shut it off and spray the fuel rail and connections down with soapy water and look for bubbles indicating a leak, this may not work so well depending on how hot it gets.
 
I'm pretty sure this the problem. Going to tackle it tomorrow. Thanks for the help, much appreciated. I'll report back once I'm done.
 
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