Engine Won't Start on First Try

surfobx031

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Aug 12, 2016
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Chesapeake, VA
Recently my '06 TJ won't crank on the first try. It tries, but then I turn key to off position then it cranks over on 2nd attempt. Battery isn't but 2 yrs old and looks to have enough juice, starter (remanufactured) was replaced May '21. Replaced starter relay last week. Ignition actuator pin was replaced 2-3 yrs ago.

What am I missing here? Ignition switch? A shitty remanufactured starter?

I have not pulled the starter off yet & tested it, figured I'd explore the forum first, but didn't find a thread where the engine did crank over on 2nd try, most threads had the engine not cranking at all.
 
Easiest way to verify fuel pressure is to let it sit over night and try to start it the next morning. If it doesn't start on the first time, cycle the key on and off three times, without starting, then try to start it. If it starts immediately after cycling the key, it's time to drop the tank!
 
Likely the check valve in the fuel pump assembly. The check valve maintains fuel pressure to the fuel rail when the engine is not running. When it fails, the fuel drains back to the tank, and it takes a few seconds for the fuel pump to get fuel back to the fuel rail.

Easy to check. Next time, turn the key on for a few seconds, then turn it off without trying to start the engine. Do this two or three times and then try to start it. If it fires right up, it’s the check valve. Replace the fuel pump assembly.
 
How does the fuel pump cause it not to crank?

By not paying attention in school where they failed to learn that early autos had a crank at the front bumper you used to crank it over until it fired off or started. We still use crank to mean turning it over even though we don't crank anything, we just turn the key a few degrees to engage the ignition switch.
 
Recently my '06 TJ won't crank on the first try. It tries, but then I turn key to off position then it cranks over on 2nd attempt
Leaky check valve inside the fuel pump which requires you replace either the fuel pump itself or the fuel pump assembly. The check valve is there to keep fuel in the fuel rail at the top-end of the engine, next to the fuel injectors. When the fuel pump's check valve fails the fuel in the fuel rail drains downward to the gas tank. The faster it leaks, the more it drains everything to the point it can start requiring 3-4 attempts to start which gives the fuel pump more time to get fuel up to the fuel rail adjacent to the fuel injectors.

I'd go for the Bosch Fuel Assembly, hopefully it's still available. AVOID STORE BRAND fuel pump or online brands like Airtex or Spectre, their products will develop the same problem just as soon as their warranty has expired if not sooner.
 
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Check leaking injectors first before swapping pump. I went through this on my XJ. Changed fuel pump twice and even wired up a timer to leave the E fan on 2 mins after shut off to combat heat soak. Turned out to be a leaky injector.

If I pull the fuel rail and cycle the key on/off a couple time to charge the fuel pump, would I be able to see the leak?
 
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If I pull the fuel rail and cycle the key on/off a couple time to charge the fuel pump, would I be able to see the leak?

Put a pressure gauge on the fuel rail and see if the pressure drops off after shutting the engine down. It should hold good pressure for at least an hour. If you have a leaky injector, it will drop fast. If one is leaking, you can then take the rail loose from the engine with the injectors on it and visually inspect them. I found mine swapping in new injectors. I wrapped insulated heat shield with adhesive around each injector ( remember I'm thinking heat soak) and I noticed where gas was soak on one and dissolved the adhesive into a mess.
 
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would this apply to a 2001 TJ? Also, the fuel pump assemblies are NOT sold any more. I am seeing various references to buying the Bosch fuel pump (which is still sold? PN????) and replacing that in the assembly. But my question is 1) will that address the potential for fuel pump failure and check valve and 2) what about the actual pressure switch - doesn't that need to be replaced? Any handy youtubes or guides out there?

On fuel injectors, not sure how easy of a job it is to diagnose and find a leaky injector. Is the injector work easier than a fuel pump job? Dropping a tank SEEMS like it would be easier than working on a top side of the motor.

Also, MPG has dropped from ~13 to about 8-9 and there is a smell of gasoline in the exhaust. But the issue primarily is that the engine takes 2-3 cycles of the key to start, then it fires right up. Hard idle and stalling at idle when motor is hot too.
 
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subscribed to this thread. Replaced the fuel pump in my 06LJ as per mechanics diagnosis to get rid of EVAP leak. Still have EVAP leak and now CRANK NO START sometimes 3 tries before it will pop off