After my 1999 Jeep Wrangler 4.0 (~70,000 miles) sits overnight in the morning it is hard to start. After turning over more times that normal it will ususally start. I thought it might be the injectors so I pulled them out and sent them off for the ultrasonic cleaning service on EBay(fuelinjectorconnection.com). Even though the Jeep has much more power now it still remains hard to start. Today I tried turning the key on/off several times, waiting on the on position to kind of "prime" the system and it started first try like I would expect it to do. So...with all that said where should I look next as to the problem?

thanks

 

Could be any number of things from a fault in the evap system to faulty crankshaft position sensor. But if I was gonna look at one component that would be the most likely culprit, I'd start with the idle air control valve. About a $80 part at the dealer and a 10 min. unplug/plug component...

 

the fuel pump is losing its "prime" to the engine.if you have access to a manual fuel gauge you can verify.

 

Funny you mention that, the jeep has a electric fuel pressure gauge in it, and it reads about 46 psi or so (the range in the hayes manual is 44-54 psi). But if you get in it in the morning and turn the key on the pressure will usually be on zero. To get the pressure up there usually I will turn the key on and off a couple of times allowing it to sit with the key on for a few seconds, each time it will go up several psi like 20, 30, then normal. I was told that the fuel pump and/or fuel pressure regulator has a check valve on it and this is designed to keep the entire system pressurized when the motor is not running, is it possible this is going bad?

Thanks

 

thats exactly whats going on.but you cant replace just the valve,you have to replace the pump assembly.mopar has a repair kit for the grand cherokees,but not the wranglers.that I have seen anyhow.the kit for the grands is pretty much just an "o" ring.

 

With all the help you provided I would like to propose another problem to let you ponder on #1 cummins fan. It is my 2005 Dodge Neon sxt 5-speed that I also had the injectors cleaned on just to get better fuel mileage. The car has about 62000 miles on it. Here is a run down on it after sitting approx 4 hrs it starts first time after leaving the ignition in the on position for a few seconds. After sitting 45 min it is hard to start, so I cycle the key a few times to attempt to "prime" the system, and I have to push the gas pedal a little else it would have idled rough and the died. After sitting another 45 min it is hard to start, first I try to cycle the key once, no luck so I do it an additional 2 times and it starts but idles a little rough the smooths out. Drove for about 5 min turn off. Immediately I restart it and it starts first try no problems. I go back out in 10 min, turn to start right away and it starts up first try and idles a little low. With all of that said what would you suggest I look into on this car? Before the injector cleaning it started up fine everytime, so the injector cleaning man told me to send them back to him so he could double check them (reclean & leak test) they were fine so I put them back in.

Thanks for any and all help.

 

Good call, #1, I knew that it was an issue on the GCs but never even gave it a single thought for his wrangler. But those are the exact symptoms...

 

pcman,I'll have to study on that one for a little while.first guess would have been leaking injector/s,but you have eliminated that.

 

pcman,I'm still leaning toward leaking injector/s.Since it sounds like you know how to r/r the injectors,leave the fuel line connected,take the fuel rail loose,leave injectors in the fuel rail,position rail so you can see the injector tips,turn the key on(dont spin engine) and look for any fuel leaking from injectors.Not second guessing the guy that checked them,its just the only cause I can up with for now that makes any sense.But If I come up with anything else I'll let you know.

 

#1 cumminsfan, I am going to check the fuel injectors for leaks after church tomorrow. Also thought I might tell you that I bought a fuel rail on ebay that has the fuel pressure test fitting on the end since mine did not to check the fuel pressure on the system. I have one question reguarding the fuel pressure on the system, if the car is off, should the fuel system remain at the same psi until the next start? Again tonight I had to drive about 2 miles, turn off for about a hour, and then the restart was difficult (rough idle which I smoothed out by pressing the gas pedal). During the entire trip the temp gauge did not get up to "true running temperature".

thanks for all help