Please help me with my 2004 kj 3.7 cant get it to start!help

Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

Ok so i have crank no start issues...so i changed the crankshaft position sensor, the camchaft position sensor (this is my 2 one in 4 days) Still nothing. (I blew a csp code, an it died on me) i changed oil, did coils an plugs, put in a new battery cause it blew a low voltage code. Still nothing...it trys to start but acts like it is not getting any fuel (but i can hear the fuel pump turn on) it just cranks but nothing but a sputter here an there. Im having no luck with getting my jeep to start...please anyone out there any advice...an im praying its not a fuel pump seeing its 200 bucks for a new one...an after already changing all the stuff a month ago my ac pully went yeah that was fun but luckly i pulled the pully out an ran a shorter belt an bypassed it...any tricks or things i can check cause i now have no codes an im just shooting in the dark trying to get this to start....

GordnadoCRD · **Posted:** Fri Mar 24, 2017 8:35 pm

What about the fuel filter?

Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

How do i check it? I really hate to randomly start just changing stuff cause its expensive

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GordnadoCRD · **Posted:** Fri Mar 24, 2017 10:23 pm

The filter and pressure regulator are part of the in-tank pump unit as well.

All the EFI systems I've ever dealt with have a port or fitting for testing fuel pressure.

If the pump is supplying correct pressure then you have a different problem. If not, then find out why.

If you got some dirty fuel you might have to drop the tank and clean it out.

flash7210 · **Posted:** Fri Mar 24, 2017 10:26 pm

You need to check fuel pressure at the fuel rail.

Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

I pulled the line off from the engine an there is no fuel coming out at all when u turn the key(i just checked it) so i got the fuel filter an im gonna change it tomorrow it was only 30 bucks...im hoping its the filter not the pump...the pumps 180 bucks... Im just hoping this fixes it....unless its a clog in the lines...an omg i really dont want to have to fix that...i was gonna do the filter tonight but i forgot to get slicone to put the plate back on with....

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Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

The car was running fine till i changed the oil...an yes i did it correct ...then it just died on me driving down the road

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GordnadoCRD · **Posted:** Fri Mar 24, 2017 11:47 pm

It's possible, perhaps probable, that those two events are not related.

You still need spark at the right time. sounds like you've addressed that.

You still need compression. If that changed you would notice right away the cranking was different.

You still need fuel. Changing the oil wouldn't have any influence on fuel delivery unless there was absolutely 0 oil pressure, which will shut off your fuel pump as a safety measure if the vehicle flips, so it won't burn everyone up.

If you're sure of everything else, and it sounds like you're already homing in on the fuel system, then that's your starting point.

If you want to verify, give it a couple seconds shot of Starting Fluid in the air filter box intake, and try to start it. If it fires and dies, you've just confirmed your problem and need to start troubleshooting. I would start with checking fuel pressure at the rail.

If it doesn't fire, then you've overlooked something with either spark or compression or timing.

Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

I tried starting fluid it still wouldnt turn over....thats where i kindof was lost...it made no sense to me but i only put it in threw the air filter cap i didnt take the hose off...but it just sputtered....i thought it must me fuel related...the odd part is when it died the oil light came on for the first time an blinked but i had just changed the oil an i know the plug was in right an tight an the filter was on right an tight so i dont know if the oil press sensor went an cause of that caused my fuel pump to shut off...if thats the case when can i find my kill swicth to turn it back on an save me on hell of a pain in the butt change filter then pump etc trying to narrow it down.

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GordnadoCRD · **Posted:** Sat Mar 25, 2017 12:05 am

There is no kill switch or reset. It simply shuts the fuel down if there is no oil pressure.

When you turn the key on, you hear the pump run, but only for a few seconds, then shuts off. Once you crank it over and oil pressure comes up, it starts running again.

Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

Oh yeah see when i turn the key i hear the pump start( the faint humming sound) but it doesnt kick over so im hoping its just the fuel filter....im gonna try fixing that tomorrow....if it works or dont i be back to post my results thank you...this sure is a fast way to get to learn the ins an out of my jeep...lol the hard way i guess....does this sound like it could be an oil pressure sensor?

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GordnadoCRD · **Posted:** Sat Mar 25, 2017 12:16 am

The fuel filter is an integral part of the Pump / pressure regulator unit inside the tank. It's not serviceable separately.

Rather... get a fuel pressure guage for high pressure EFI system, and check if you're getting full pressure at the rail. If you have gunk in the tank plugging things up, you won't be getting full pressure.

If you are getting full pressure, then your problem isn't in the tank / pump / regulator / filter area.

Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

I know two crankshaft sensor ends snapped off an are in my oil pan that couldnt be cause it from not starting right? I just cant get it to run to get it to a lift to drop the oil pan an remove them yet...just asking cause im trying to really elimanate any possibles....an when i removed the fuel line from rail the was no gas that came out when i tried to crank it over...

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GordnadoCRD · **Posted:** Sat Mar 25, 2017 1:46 am

Please don't get insulted by my asking this, I just want to be thorough.

Are you 100% sure you are not out of fuel?

Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

I have a half a tank...i questioned it to an put five gallons in

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Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

Update did fuel pump an filter still no start....could this be my ecm????

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tjkj2002 · **Posted:** Sat Mar 25, 2017 8:45 pm

GordnadoCRD wrote:

The fuel filter is an integral part of the Pump / pressure regulator unit inside the tank. It's not serviceable separately.

Rather... get a fuel pressure guage for high pressure EFI system, and check if you're getting full pressure at the rail. If you have gunk in the tank plugging things up, you won't be getting full pressure.

If you are getting full pressure, then your problem isn't in the tank / pump / regulator / filter area.

Only starting in '05 for gas models.

Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

Ok so i did it anyways still nothing....it cranks no start....could it be my ecm im getting no pressure read on my fuel line but the pump is new

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Urlildogtwo · **Joined:** Fri Mar 24, 2017 7:32 pm **Posts:** 16

But gas is coming out the rail

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tjkj2002 · **Posted:** Sat Mar 25, 2017 8:50 pm

Urlildogtwo wrote:

Update did fuel pump an filter still no start....could this be my ecm????

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So many un-answered ?'s......................

-Actual fuel pressure at the test port? Taking fuel line off and cranking does not count.
-Power at pump when commanded?
-Cam signal? And correct? Using a scope.
-Crank signal? And correct? Using a scope.
-With high end scanner is cam/crank signal in sync?
-Fuel injector pulse?
-Spark?
-Engine in time?

That's just to start.

Please help me with my 2004 kj 3.7 cant get it to start!help

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