I have an 04 Jeep Wrangler unlimited LJ 4.0 4 speed 42RLE trans and I am having this problem where if my engine is cool and I go to start it it will take like 10 seconds to start and it will spuder and start. But once it’s started it runs just fine. I have replaced the spark plugs recently but if the engine has been ran recently than it will start up just fine but if it hasn’t been started in an hour or more it will have a hard time starting. What could this be?
4.0 takes 10 seconds to start when cold
- Thread starter Tzerambo
- Start date
That's caused by a leaky check valve inside your fuel pump allowing the fuel to leak back down out of the engine to the gas tank instead of staying put like it's supposed to for fast starts. The extra time yours is taking to start after it sits a while is how long it takes the fuel pump to get the fuel back up from the tank to the fuel injectors.
Avoid store brands or online brands like Airtex or Spectre, go for a Bosch replacement fuel pump which is what the factory installed. You want the Bosch 69316 like is available at www.rockauto.com or https://www.amazon.com/dp/B000BZL922/?tag=wranglerorg-20
Avoid store brands or online brands like Airtex or Spectre, go for a Bosch replacement fuel pump which is what the factory installed. You want the Bosch 69316 like is available at www.rockauto.com or https://www.amazon.com/dp/B000BZL922/?tag=wranglerorg-20
Have you done any troubleshooting?
Have you visually inspected under the hood or the fuel lines from the tank to the engine compartment?
I would find a service manual and start checking fuel pressure and go from there.
Have you visually inspected under the hood or the fuel lines from the tank to the engine compartment?
I would find a service manual and start checking fuel pressure and go from there.
Any luck with fixing your starting issue? Is it definitely fuel related?
I had the same symptoms, and it progressed to about 45 seconds and 4-5 times of turning the key on and off before the Jeep would start. However, once it got to late Spring my problem would disappear until the weather cooled down in September. Then it would get worse throughout the Winter again. After checking EVERYTHING, and replacing the fuel pump twice, it wound up being the computer. The connections in the computer would contract in cold weather and would need electrical current to heat up in the Winter, hence keying the ignition several times. Once at the correct temperature, the Jeep would start right up and run normally.
An easy test on this would be to get your Jeep going and drive for a while at normal temperature. Come home, disconnect your computer (super easy) and put it in the freezer for 20-30 minutes. Plug it back into the Jeep and try to start it. If it sputters again, then you'll know it's the computer.
I got a refurbished unit for $187 and my Jeep has been running perfectly since.
Good luck.
I had the same symptoms, and it progressed to about 45 seconds and 4-5 times of turning the key on and off before the Jeep would start. However, once it got to late Spring my problem would disappear until the weather cooled down in September. Then it would get worse throughout the Winter again. After checking EVERYTHING, and replacing the fuel pump twice, it wound up being the computer. The connections in the computer would contract in cold weather and would need electrical current to heat up in the Winter, hence keying the ignition several times. Once at the correct temperature, the Jeep would start right up and run normally.
An easy test on this would be to get your Jeep going and drive for a while at normal temperature. Come home, disconnect your computer (super easy) and put it in the freezer for 20-30 minutes. Plug it back into the Jeep and try to start it. If it sputters again, then you'll know it's the computer.
I got a refurbished unit for $187 and my Jeep has been running perfectly since.
Good luck.
'Tis the season for fuel leaks when it starts getting colder. Especially If you have any soft fuel lines with crappy worm drive clamps, they won't stay as snug when it gets colder and they can sometimes allow fuel leaks (i.e. fuel pressure drop off). These clamps (if you have them) should be replaced by proper OEM spring clamps that change tension with temperature. Sometimes these types of leaks can be found by following your nose when the engine has gotten cold and has sat long enough for the tiny leak to start occurring. However, once fuel pressure is relieved, then it hard to detect the leak again. Might need to pressurize when cold to figure it out.
Well my Jeep now cranks like 6 times before it starts every time no matter how cold or hot it is it has been doing this everyday since the start of the summer and now that it is cold out side it is still starting the same cranks 6 times then starts. But if I prime the fuel pump a few times it will fire right up. I’m thinking it is the fuel pressure regulator going out which is in the fuel pump module on the 04 module.
Yeah, sounds like a fuel issue.
I always like to provide another perspective since I chased my tail for ages thinking mine was a fuel problem. Good luck getting it all resolved.
I always like to provide another perspective since I chased my tail for ages thinking mine was a fuel problem. Good luck getting it all resolved.
IT's the check valve not the pump itself. As explained above the check valve prevents fuels from draining back to the tank and keeps the fuel line full. When you turn your key to the on position the fuel pump comes on. Try turning on your key for a few seconds to allow the pump to fill the line prior to engaging the starter.
fuel pressure for sure. likely a faulty pump but there are many causes.
I recall several GMC pickups catching fire after running out of gas because the fuel pump would run till it caught fire trying to build pressure, impossible when the tank was empty. Back when being a fire fighter was a blast.
I recall several GMC pickups catching fire after running out of gas because the fuel pump would run till it caught fire trying to build pressure, impossible when the tank was empty. Back when being a fire fighter was a blast.