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02-17-2013, 10:51 PM
#46
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Year: 1996
Model: Cherokee
Engine: i-6 4.0
Going to touch the gas for the first Time...
Let off and back down to low revs, maybe its just suffering from a vary low idol? And causing it to stall out when you let off?
Let off and back down to low revs, maybe its just suffering from a vary low idol? And causing it to stall out when you let off?
02-17-2013, 10:55 PM
#47
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Year: 1996
Model: Cherokee
Engine: i-6 4.0
The timing is set by the PCM, (not adjustable). Another poster just had issues with cheap gas that seem to have gone away when he switched stations. I'd be careful just leaving it run...it will drain the batery of course if it dies. Also once (dummy me) I let one run with out PS fluid and melted the pump.(essentially).
Boy, I get that you must be at wits end. Do you have a digital volt meter? Checking the sensor grounds is really something to rule out. Also you might put 32oz. of isopropel (rubbing alcohol) in it and drive it enough to mix it in there. It will mix with water and help move it through...might help. Deffenantly that can be an issue.
Some of the guys who know your jeep better might show up tomorrow.
A last thought..rrrrr FSM says disconnecting the battery for just a minute resets the PCM, I think. Guys "in the know" have posted it takes 8-10 hrs for "the capacitors to bleed down". I only mention that because it' easy, cheap, and harmless!
Boy, I get that you must be at wits end. Do you have a digital volt meter? Checking the sensor grounds is really something to rule out. Also you might put 32oz. of isopropel (rubbing alcohol) in it and drive it enough to mix it in there. It will mix with water and help move it through...might help. Deffenantly that can be an issue.
Some of the guys who know your jeep better might show up tomorrow.
A last thought..rrrrr FSM says disconnecting the battery for just a minute resets the PCM, I think. Guys "in the know" have posted it takes 8-10 hrs for "the capacitors to bleed down". I only mention that because it' easy, cheap, and harmless!
02-17-2013, 10:59 PM
#48
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Year: 1996
Model: Cherokee
Engine: i-6 4.0
also the timing isn't adjustable it is set by the PCM but the injector pulse is adjustable by the PCM, and maybe with time.. Idk..
02-17-2013, 11:16 PM
#49
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
No, pretty sure they only are adjustable till 90. Normally I guess "drivability" is what gets mentioned there. Shifting issues or *******.
The weekends sometimes can be slow...hopefully someone with more smarts than me might show up tomorrow. I'm just learning my old Renix, mostly.
I'm not sure what Highmilage was getting at. As far as I know the clutch switch or whatever only locks out starting. Is your dieing related to the using clutch?
The weekends sometimes can be slow...hopefully someone with more smarts than me might show up tomorrow. I'm just learning my old Renix, mostly.
I'm not sure what Highmilage was getting at. As far as I know the clutch switch or whatever only locks out starting. Is your dieing related to the using clutch?
When you depress or release the clutch if that switch is sticking or shorting out it can kill the engine. Yes it will only relate to the clutch pedal being released or depressed.
02-17-2013, 11:22 PM
#50
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Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
I gather the stop on the throttle plate is set so the plate just doesn't contact, make a groove, get stuck in the aluminum side of the TB. THEN the IAC basically does the mixing we might have done with the idle mix screw in days of old. It's motor makes a PCM controlled vac leak... I think.
You might be on to something. A new, replacement TB? Yea, that plate should just almost touch. Zero clearance might be nearly correct. I suppose if the gap were too big it would be like a vacuum leak. I don't think too close is a problem other then gouging the TB...But again I don't know...If you have the original IAC you could always swap than in ,,,,for fun!
Check the grounds!
Here's a "stretch". The gap is too big causing low vacuum which the map is reading and telling the PCM to increase pulse width, flooding it.
You might be on to something. A new, replacement TB? Yea, that plate should just almost touch. Zero clearance might be nearly correct. I suppose if the gap were too big it would be like a vacuum leak. I don't think too close is a problem other then gouging the TB...But again I don't know...If you have the original IAC you could always swap than in ,,,,for fun!
Check the grounds!
Here's a "stretch". The gap is too big causing low vacuum which the map is reading and telling the PCM to increase pulse width, flooding it.
Last edited by DFlintstone; 02-17-2013 at 11:28 PM.
02-18-2013, 01:30 AM
#51
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Year: 1996
Model: Cherokee
Engine: i-6 4.0
I gather the stop on the throttle plate is set so the plate just doesn't contact, make a groove, get stuck in the aluminum side of the TB. THEN the IAC basically does the mixing we might have done with the idle mix screw in days of old. It's motor makes a PCM controlled vac leak... I think.
You might be on to something. A new, replacement TB? Yea, that plate should just almost touch. Zero clearance might be nearly correct. I suppose if the gap were too big it would be like a vacuum leak. I don't think too close is a problem other then gouging the TB...But again I don't know...If you have the original IAC you could always swap than in ,,,,for fun!
Check the grounds!
Here's a "stretch". The gap is too big causing low vacuum which the map is reading and telling the PCM to increase pulse width, flooding it.
You might be on to something. A new, replacement TB? Yea, that plate should just almost touch. Zero clearance might be nearly correct. I suppose if the gap were too big it would be like a vacuum leak. I don't think too close is a problem other then gouging the TB...But again I don't know...If you have the original IAC you could always swap than in ,,,,for fun!
Check the grounds!
Here's a "stretch". The gap is too big causing low vacuum which the map is reading and telling the PCM to increase pulse width, flooding it.
Last edited by jeepsurfer1; 02-18-2013 at 02:35 AM.
02-18-2013, 07:39 AM
#52
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Year: 1997
Model: Cherokee
Engine: 4.0L
Just wondering, was the TB replace after this problem started? Do you still have the orginal? What injectors are you using- Stock or "upgraded"? Were these also changed after the problem?
If you bought the Jeep with these items already installed then it's possible this problem has always been there. I really don't think I would be taking it to Florida, but to each his own.
If you bought the Jeep with these items already installed then it's possible this problem has always been there. I really don't think I would be taking it to Florida, but to each his own.
02-18-2013, 10:29 AM
#53
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Year: 1996
Model: Cherokee
Engine: i-6 4.0
Just wondering, was the TB replace after this problem started? Do you still have the orginal? What injectors are you using- Stock or "upgraded"? Were these also changed after the problem?
If you bought the Jeep with these items already installed then it's possible this problem has always been there. I really don't think I would be taking it to Florida, but to each his own.
If you bought the Jeep with these items already installed then it's possible this problem has always been there. I really don't think I would be taking it to Florida, but to each his own.
02-18-2013, 04:43 PM
#55
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Year: 90,84
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The thought did cross my mind that the guy you bought it from maybe had had it sitting for a while. The ethanol blend we get here doesn't like that. It absorbs water and separates. Just rambling...I suppose that would mix in in a two hr drive, still maybe some water though....
I would still see that I had less than an ohm from the ground circuit to the neg post. (I picked up 1/5 an ohm cleaning the connection at the dipstick).
Too often people are back in a day or a week. Unless it was water or the map you might be one of them! Hope not.
I would still see that I had less than an ohm from the ground circuit to the neg post. (I picked up 1/5 an ohm cleaning the connection at the dipstick).
Too often people are back in a day or a week. Unless it was water or the map you might be one of them! Hope not.
02-18-2013, 05:24 PM
#56
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Year: 1994 1993
Model: Cherokee
Engine: 4.0
It's a witch! Burn it! But seriously it sounds as if things started getting solved when you said you changed the MAP a number of posts ago. My last serious no start problems where a result of a problem in that area so maybe it just took a bit for it to settle back in once you messed with that.
02-18-2013, 06:52 PM
#57
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Year: 1996
Model: Cherokee
Engine: i-6 4.0
The thought did cross my mind that the guy you bought it from maybe had had it sitting for a while. The ethanol blend we get here doesn't like that. It absorbs water and separates. Just rambling...I suppose that would mix in in a two hr drive, still maybe some water though....
I would still see that I had less than an ohm from the ground circuit to the neg post. (I picked up 1/5 an ohm cleaning the connection at the dipstick).
Too often people are back in a day or a week. Unless it was water or the map you might be one of them! Hope not.
I would still see that I had less than an ohm from the ground circuit to the neg post. (I picked up 1/5 an ohm cleaning the connection at the dipstick).
Too often people are back in a day or a week. Unless it was water or the map you might be one of them! Hope not.
And I plan on adding seafoam to the gas to remove any water, I will also take it for a test drive tonight for about 30 miles to confirm or deni that the problem is gone/ or still there
02-19-2013, 09:15 PM
#59
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Year: 90,84
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Nothing wrong with knowing your 02 sensor is good, being so important to MPG.
You might find wet plugs if it quit sparking is why I suggested checking spark right as it's messing up. You have a cam sensor and a coil and ICU, besides the CPS.
Also CPT's deal. He needed to unplug his engine coolant sensor....(down under).
You might find wet plugs if it quit sparking is why I suggested checking spark right as it's messing up. You have a cam sensor and a coil and ICU, besides the CPS.
Also CPT's deal. He needed to unplug his engine coolant sensor....(down under).
02-19-2013, 09:21 PM
#60
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Year: 1996
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Nothing wrong with knowing your 02 sensor is good, being so important to MPG.
You might find wet plugs if it quit sparking is why I suggested checking spark right as it's messing up. You have a cam sensor and a coil and ICU, besides the CPS.
Also CPT's deal. He needed to unplug his engine coolant sensor....(down under).
You might find wet plugs if it quit sparking is why I suggested checking spark right as it's messing up. You have a cam sensor and a coil and ICU, besides the CPS.
Also CPT's deal. He needed to unplug his engine coolant sensor....(down under).