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Old 09-20-2010, 08:42 PM   #1
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Stumbling

On my 2.5 in 2nd and 3rd at a constant speed between 2 and 3,000 rpm it will stumble and buck but only at a constant speed if I am on the gas it doesnt do it near as bad. Any Ideas?

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Old 09-20-2010, 08:44 PM   #2
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Almost forgot it will idle kinda high some times. Pulling up to a stop it will sit as 1100 or 1200 rpm for a min then drops back to normal.

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Old 09-21-2010, 07:25 AM   #3
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Changed so far
crank position sensor
Camshaft position sensor
fuel filter
dropped tank looked new inside
new plugs bosh +2 (done by PO)
new cap rotor and wires
new coil should be here today installed by tonight
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Old 09-21-2010, 07:45 AM   #4
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Are you throwing any codes? I would guess it to be the TPS..
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Old 09-21-2010, 09:44 AM   #5
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Just a code 33 A/C relay I think.
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Old 09-21-2010, 08:19 PM   #6
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Sea Foamed, Throttle body cleaned and new Accel Mopar supercoil stil doin it what next? Any ideas? I'm grasping at straws here guys.
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Old 09-22-2010, 09:57 AM   #7
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Sea foam made it worse I thin now at 2500 rpm under mild acceleration it will studer and miss and some times backfire through the exhaust. Under hard acceleration it doesn't do it. Also the idle will hang out at almost 1500 the drop to 1000 eventually settling out where it should be after 20-30 sec.
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Old 09-22-2010, 09:58 AM   #8
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Got a code 44 to day too
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Old 09-22-2010, 10:01 AM   #9
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Could I maybe have gotten the timing wrong when
I did the cam sensor? didn't feel like there was any real adjustment in there.
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Old 09-22-2010, 11:38 AM   #10
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Check the MAS on the firewall just above the valve cover for a leak. How old is the ox sensor?
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Old 09-22-2010, 08:24 PM   #11
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Did the map sensor tonight haven't drove it yet though wasn't up for getting ticked off at the jeep tonight. Have a new set of plugs to go in tomorrow but want to wait and see what that sensor will do first.
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Old 09-22-2010, 08:26 PM   #12
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I have no Idea how old the o2 sensor is. That is on the list soon to if this latest round of parts doesn't do the trick.
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Old 09-23-2010, 06:29 AM   #13
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Map sensor helped the high idle some but the stumbling is still there
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Old 09-23-2010, 07:07 AM   #14
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Here's what I came up with for a 44 code "An open or shorted condition exists in the engine coolant temperature sensor circuit or a problem exists in the PCM's battery temperature voltage circuit." I'm gonna go with the PCM's battery temp.. If it was your coolant temp you would see that in your gauges..
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Old 09-23-2010, 10:17 AM   #15
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There is a secondary coolant sender by the thermostat that doesn't run the gauge I may try and replace that I think it runs the fuel injection. I have thrown a lot of parts at this problem wish somebody who has had it would look at this thread.
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Old 09-23-2010, 01:36 PM   #16
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That could be it, if the sensor gives a false reading, the injectors won't operate properly. I had a similar problem on an old Toyota 4 cyl, ran really crappy. I would not discount the plugs, most times they are OK but all it takes is one to be misfiring and with the 4 banger you can really tell. I've had them bad right out of the box..
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Old 09-23-2010, 02:50 PM   #17
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I have a set to go in just haven't had time to put them in yet. Bought the coolant sensor today hopefully that will do it.
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Old 09-23-2010, 10:16 PM   #18
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I had a very similar problem only mine would backfire after the stumbling and knocking

I ended up changing

TPS
Crank shaft position sensor
Both Temp sensors
Plugs and Wires
and Finally the O2 Sensor and when i Changed this It finally started to drive right

Maybe it was a combination of all but I would do the O2 next
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Old 09-24-2010, 07:21 AM   #19
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I think o2 is going to be my next step I changed the temp unit at the thermostat last night and it still does it. If the o2 sensor doesn't square it away I think I may try the TPS. I get a backfire every now and then through the exhaust so we might have the same thing going on.
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Old 09-26-2010, 07:57 PM   #20
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New O2 sensor I'll let ya'll know how it works out tomorrow
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Old 09-27-2010, 02:31 PM   #21
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No luck with the O2 sensor just as bad as before. Did plugs and TPS today and its still having issues. Idle Control Motor maybe? I am starting to get really frustrated here all of these sensors are starting to get expensive.

The list so far
Crankshaft position sensor
camshaft position sensor
coil
plugs
TPS
O2 sensor
Coolant sending unit
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Old 09-27-2010, 03:10 PM   #22
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I know this might sound stupid but have to tried a couple of cans of injector cleaner?
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Old 09-27-2010, 07:28 PM   #23
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I ran one right after I bought it about a month ago. Unplugged the IAV today and the idle didn't change so I wonder if that may be the cause of the high Idle.

Forgot to put in the list
Fuel filter
MAP sensor
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Old 09-27-2010, 10:41 PM   #24
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Make sure your wiring harness is intact. I noticed alot of mine had been burnt up. That would possibly be causing some problems
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Old 09-28-2010, 01:03 PM   #25
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Intake Air valve should be in this afternoon and I picked up a cap and rotor too just in case I damaged it when I did the cam shaft sensor.
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Old 09-28-2010, 06:55 PM   #26
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Man i went thru the same thing with my jeep...I had a check engine light on when i got it and the guy said it had the miss, so i just assumed it was plugs wires and the cap, changed that , no fix....well then i changed the coil, no fix...i changed the map sensor, fuel filter, then the injecters, still didnt fix it...i then changed the tps senor and still no fixy, by this time i am really discusted with it....I went last week and got a new fuel pump and a O2 sensor...when we took the tank down out of the jeep my rubber fuel line were kinked....so we changed the rubber lines, the pump, the pump filter, and the o2 sensor and it took care of my problem, check engine light, miss and all. Its been a real experience for me i tell ya....hope this helps man and good luck with it....oh and you probably already know this, but sure and reset the computer when you put new parts on it.
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Old 09-28-2010, 07:13 PM   #27
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New cap rotor and intake air valve today no better. I'll check those lines I have already had the tank down once and it was super clean in there.
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Old 09-29-2010, 03:39 AM   #28
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Crunch you say it runs rough at speed and okay when accelerating which means it is probably running on the rich side at partial throttle but getting enough air to run at wide open or moderate throttle. Have you checked you exhuast manifold for leaks? That could cause you to run rich and stumble at part throttle and also cause a abnormal idle when the engine slow. The O2 sensor sees the extra oxygen and richens the mixture. You said you changed plugs what plugs are you running?
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Old 09-29-2010, 04:37 AM   #29
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Quote:
Originally Posted by Fweaky View Post
Crunch you say it runs rough at speed and okay when accelerating which means it is probably running on the rich side at partial throttle but getting enough air to run at wide open or moderate throttle. Have you checked you exhuast manifold for leaks? That could cause you to run rich and stumble at part throttle and also cause a abnormal idle when the engine slow. The O2 sensor sees the extra oxygen and richens the mixture. You said you changed plugs what plugs are you running?
X2, I would check the exhaust/intake manifold for leaks.
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Old 09-29-2010, 06:05 AM   #30
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I would of put a fuel pump in .check the fuel pressure.they will run with low pressure .but very crappy.

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