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-   -   extensive cranking on strart up 2005 Grand Cherokee 4.7l (http://www.jeepgarage.org/f77/extensive-cranking-on-strart-up-2005-grand-cherokee-4-7l-41719.html)

jeffw 05-05-2012 09:43 AM

extensive cranking on strart up 2005 Grand Cherokee 4.7l
 
Hi All, Just found this site, looks great... I just bought a 2005 Grand Cherokee 4.7L... When its cold or been sitting for a while, it cranks over for about 3 seconds before it starts, then stumbles for a sec. Then it runs fine... I Changed the spark plugs (they were very wore) and it still does it... Just wondering if anyone here has had that problem and knows the fix??...

Thanx in advance... Jeff..

Mr Chill 05-05-2012 01:15 PM

Re: extensive cranking on strart up 2005 Grand Cherokee 4.7l
 
Kinda sounds like a fuel issue.

Anyone know if its possible for the fuel system on these to lose its prime? I had an f-body that did this after I ran it out of fuel once. It was a liquid-cooled pump in the tank and running it out of gas burnt up the pump. Took awhile to get it started but it ran fine.

2005JGC 05-05-2012 02:40 PM

Re: extensive cranking on strart up 2005 Grand Cherokee 4.7l
 
Yep I would get a fuel pressure gauge on it, start it, then shut it off and watch the gauge. if it drops (SOME bleed off is normal but it should stop bleeding at a point if it does). If it drops then your likely looking at a pump, but possibly a stuck open injector, damaged fuel line/leaking connection.

jeffw 05-06-2012 07:17 AM

Re: extensive cranking on strart up 2005 Grand Cherokee 4.7l
 
Thanx a lot for the responses, Guys... I forgot to add in the origanal post that- When it fires up, (after sitting for a long while) it smokes some black and you can smell raw fuel at the exhaust pipe for a few secs, then all is good... Im starting to wonder if it is a bad injector... I have no idea how you would figure out what injector it would be... I will put a gauge on the fuel rail and whatch the pressure... Thanx again..

Cheers... Jeff..

jeffw 12-11-2012 09:50 AM

Re: extensive cranking on strart up 2005 Grand Cherokee 4.7l
 
Hi all, this site is awesome, so much good info, you guys are great!!!... Well I changed out the fuel pump/regulator and at times it still turns over to much before firing... Im now thinking bad injector...If I let it sit for 20 min or so, then try to start it, thats when it cranks the most... If I let it sit overnight it fires up perfect almost every time due to the fact the fuel has dissipated in the cylinder over the many hrs.? If I turn it off then start it right away it fires perfect. That bein said, Im going to change the injectors... What do you guys think, should I find the bad injector/injectors and just change them, or should I change all 8? I have heard from some mechanics to change only the bad ones, and from others heard to change them all. My JGC Rocky Mountain Edition has 220 000km/138000 miles on her.

Thanx Guys/Gals... Jeff..

Frango100 12-11-2012 04:11 PM

Re: extensive cranking on strart up 2005 Grand Cherokee 4.7l
 
When it was me, i would take them all out and let them be cleaned by a shop who has the right cleaning machine. If after the cleaning still one is bad, i would only replace that one.

jeffw 12-11-2012 06:10 PM

Re: extensive cranking on strart up 2005 Grand Cherokee 4.7l
 
Thanx Frango, for the input.. Ill do some searching for a shop here in town that cleans injectors...

Thanx..

Cheers... Jeff..

Iain McDonald 02-14-2013 08:20 PM

Re: extensive cranking on strart up 2005 Grand Cherokee 4.7l
 
Hi
I have a 2005 4.7L Grand Cherokee. It sounds like it has exactly the same problem. I had my injectors cleaned and they bench tested fine. My mechanic thinks they are faulty though and are bleeding fuel into the cylinder, thereby temporarily flooding the motor.
What was the outcome for you jeffw?


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