Day 6

[XJReaper]

So the engines in and vacuum leak is fixed. I now need to fix a new crack in the exhaust manifold at a weld joint and figure out why there is so much shake at 1.25 rpm.

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[JPNinPA]

What year is the engine? They make an improved manifold that is less prone to crack.
Check motor mounts. Worn mounts allow your engine to move and over stress the exhaust.

Also make sure your system can move and is for too compressed or in tension.

For the shake is it 1,250 rpm or the throttle position. If it's is the throttle position clean or replace the TPS.
Use only OEM sensors. Others fail early or do not work up front.


JPNinPA
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[XJReaper]

What year is the engine? They make an improved manifold that is less prone to crack.
Check motor mounts. Worn mounts allow your engine to move and over stress the exhaust.

Also make sure your system can move and is for too compressed or in tension.

For the shake is it 1,250 rpm or the throttle position. If it's is the throttle position clean or replace the TPS.
Use only OEM sensors. Others fail early or do not work up front.


JPNinPA
Using Jeepz.com app

I changed the mounts when I put in the motor. I cleaned the tb. But I'm finding differences between motors. The one installed is a 92 motor. The one that came out was a 94. I'm having a hard time finding the coolant temp connector. The plug comes out of the drivers side of block but there is no connecting plug from harness.

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[JPNinPA]

Here is the new/improved exhaust.
https://www.quadratec.com/products/17601_0013_07.htm

Diagram of temp sensor


Regards,
JPNinPA

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[XJReaper]

Here is the new/improved exhaust.
https://www.quadratec.com/products/17601_0013_07.htm

Diagram of temp sensor


Regards,
JPNinPA

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Very nice. I think I am going to use the old one that doesn't have a crack in it.

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[XJReaper]

Very nice. I think I am going to use the old one that doesn't have a crack in it.

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Just till I get the money up.

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[JPNinPA]

Vac diagram
https://www.jeeppartsoverstock.com/...RWOOD--GRAND-CHEROKEE--COMANCHE/0000099I.html


Regards,
JPNinPA

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[XJReaper]

Vac diagram
https://www.jeeppartsoverstock.com/...RWOOD--GRAND-CHEROKEE--COMANCHE/0000099I.html


Regards,
JPNinPA

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Picked up the Hanes Manuel yesterday for $24 from oreillys. The shake is at1,250 rpm only a little bit now but more than it ever was. Soon as you get above 1,250 it is smooth sailing.

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[JPNinPA]

The 92 4.0L has two temp sensors. One on the thermo housing that goes to the PCM. And one on the driver side rear that goes to the dash gage.
I can't seem to locate the correct diagram for this.


The factory service manual is your best reference.

Regards,
JPNinPA

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[XJReaper]

The 92 4.0L has two temp sensors. One on the thermo housing that goes to the PCM. And one on the driver side rear that goes to the dash gage.
I can't seem to locate the correct diagram for this.


Regards,
JPNinPA

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I had a feeling that one in the back of the block had to do with thermos gauge. I do appreciate all the help and advice.

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[JPNinPA]

So the 1250rpm rough running is likely the TPS. A quick check is unplug the TPS and see if the problem stops. Without the TPS you will have other issues so don't run like this.


Only use OEM sensors.

Regards,
JPNinPA

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[JPNinPA]

Another thought but would span more than1250 rpm is your exhaust leak.
The O2 feeds info back to the PCM for air fuel ratios. Once corrected this may go away.


JPNinPA
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[XJReaper]

Another thought but would span more than1250 rpm is your exhaust leak.
The O2 feeds info back to the PCM for air fuel ratios. Once corrected this may go away.


JPNinPA
Using Jeepz.com app

Yesterday I filled the crack on the exhaust manifold with Muffler weld I let it set up today I was going to check it and see if it held or if I have to replace the whole manifold.

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[XJReaper]

So the 1250rpm rough running is likely the TPS. A quick check is unplug the TPS and see if the problem stops. Without the TPS you will have other issues so don't run like this.


Only use OEM sensors.

Regards,
JPNinPA

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Thank you I will check that out today appreciate all the help.

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[XJReaper]

So the 1250rpm rough running is likely the TPS. A quick check is unplug the TPS and see if the problem stops. Without the TPS you will have other issues so don't run like this.


Only use OEM sensors.

Regards,
JPNinPA

Sent using TapTalk

Thank you I will check into that today I appreciate all the help

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