Bad miss
10-12-2011, 09:45 PM
#1
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Year: 1999
Model: Cherokee
Engine: Inline 6
Bad miss
A while back my jeep started missing kinda bad. When i go to start it, it cranks a lil then starts. And at idle, it misses bad and puts almost. Then once i get going, if i go from high to low rpm's, it lunges really bad and has almost 0 power. We've replaced a bunch of sensors and all the spark plug wires and dist. cap. What could this be? 
10-13-2011, 08:10 AM
#3
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Have you checked the fuel pressure? Any CELs?
10-13-2011, 08:23 AM
#4
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10-13-2011, 08:33 AM
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Crankshaft Position Sensor could be bad. I don't think they throw a CEL for that either.
10-13-2011, 09:38 PM
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10-13-2011, 11:06 PM
#8
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Year: 90,84
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Engine: 4.0,2.5
You did check the gap? Even new ones should be checked. They are way to important to shine that simple task. The gap grows a little every day, then idle will get bad and it will start to stumble and miss.
I mean I guess you DID, I just don't see "checked the gap.......Do you know if it's time for a fuel filter?
I mean I guess you DID, I just don't see "checked the gap.......Do you know if it's time for a fuel filter?
Last edited by DFlintstone; 10-13-2011 at 11:16 PM.
10-14-2011, 12:54 PM
#9
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Year: 1999
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Now i feel dumb here, but what do ya mean by the gap?
And i'm gonna change the oil, and oil filter this weekend, along with fuel filter.
And i'm gonna change the oil, and oil filter this weekend, along with fuel filter.
10-14-2011, 01:15 PM
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Year: 1991
Model: Cherokee
Engine: 4.0 L
oh yeah........this REALLY may sound dumb.......but I am gonna say it anyway......
new wires and cap etc. right?
are you 100% sure that EACH wire connector had an AUDIBLE and a TACTILE feel of a "click" when you attached them to the plugs
( I have a hellava time with these when I have changed the wires)
are you 100% sure EACH spark plug is snugged into its hole tightly? (not gorrila tight, but tight).
an last but not least, you got a new rotor with cap right?
cheers!
cpnwrench
10-14-2011, 01:20 PM
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Year: 1997
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Engine: 4.0, comp cam, 99 intake, apn header, neon injectors, Thunderbolt 2.5" High Flow Cat
has the distributor been pulled and reinstalled? maybe off a tooth? is the timing chain stretched? if neither of these and you know the plugs, wires, cap, rotor, firing order are all good, check your coil, your crankshaft position sensor, and your camshaft position sensor. isn't much more to it.
10-14-2011, 01:25 PM
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Hey...this is what this forum is for! When you have the plug out, it's the space between the little tip there in the center and the "J" shaped thing. (those are the electrodes". I like the plug gapper that is like a 1/2 dollar with different widths around the edge. There's also wire types that may be more accurate. Also I have a deal like pliers with a wheel you turn to select different gaps. Then, after a few 100 you can almost do it by eye.
10-28-2011, 08:37 AM
#14
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Found the solution, i had a broken solenoid on one of my spark plugs, and a bad gap. But now the ol jeep has a real fine vibration, AND has low pressure to the 1 and 5 cylinders.
10-28-2011, 09:08 AM
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Year: 1990
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