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4.7 wont start

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  #1  
Old 07-16-2011, 05:27 PM
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Default 4.7 wont start

Ok I got a1999 Jeep grand Cherokee.with a 4.7. I'm hoping u guys can help me cause there isn't alot of ppl on the Jeep section here on dodgeforum.
I know the 3rd gens use the same motor so I could use some help.

The truck cranks and attwmps the fire but wont start. Ialready checked coolant and oil for signs of a blown head gasket and all looks good. What should I try next????

Thx in advance matt
 
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Old 07-16-2011, 07:40 PM
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Every once in a while my hemi gets a wild hair and doesn't want to crank right up, I end up having to crank for it a little and hold the gas to the floor.
 
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Old 07-18-2011, 12:21 AM
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well i gave that a shot and no go. i tried at wide open throttle and spraying starting fluid straight into the intake. and it fires a couple times but wont run
 
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Old 07-18-2011, 10:32 AM
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Cranks but wont fire huh. Well did u notice any problems with starting the jeep problem or any other mechanical problems? If not sounds like an electrical problem.
 
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Old 07-18-2011, 10:53 AM
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Make sure to check ur fuel rail to see if ur gettung fuel. Just unscrew the cap on the rail and press down the depressurization pin and fuel should come out. If not it could be a bad sending unit/fuel pump.
 
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Old 07-19-2011, 02:23 AM
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nope wont fire. i havent noticed any mechanical problems yet. like i said i just bought it not running so idk what happened when it died. do you know how to check the cam timing on the 4.7s??? i have no clue with the single overhead cams on a v8. i can a 4 bangor but dunno how to check this one.

thx matt
 
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Old 07-19-2011, 12:17 PM
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Id really suggest checking if u have any fuel pressure.
 
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Old 07-19-2011, 04:03 PM
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fuel, fire, and timing. start there. break out the chilton/haynes for some help/guidance.

trying to diagnose online is like working in the dark, gotta see/touch/test it for us to be any real help. all we can give are suggestions like those already mentioned.

for me, I start with fuel. from the tank to the injector and back. pressures, signals, obstructions...

spark, signals, shorts...

and last but not least, timing signals for everything. and without a scan-tool, it will be a chore chasing down signals.

good luck.

But this is the part that really worries me...
Originally Posted by matt72991
like i said i just bought it not running so idk what happened when it died.
did I read/understand that correctly? you bought it not running? and don't be to sure that all the 4.7's are the same. I know of 2 versions used in the 3rd Gen Rams.
 

Last edited by slimvela; 07-19-2011 at 04:09 PM.
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Old 07-23-2011, 08:07 PM
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Ok so today I took the valve covers off and the front cover. The cams r both in time. The timing chain on the drivers side has slack but I dont think its enough to cause this issue??? Maybe? Any idea. I got fuel at the rails.
 
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Old 07-23-2011, 11:01 PM
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you haven't said if your getting spark or fuel pressure...
 


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