Rough Start
Renix Super Guru
Joined: Mar 2008
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From: In yourz postez fissin jurr spelinzs
Year: 1990XJ/1989MJ
Model: Comanche
Engine: 4.0L Renix
Turn on the key when you get in and wait about 5-10 seconds before turning the motor over, This allows the fuel pressure to build in the fuel rail and should lower the cranking time by about half.
Keep in mind that the CPS needs to see at least 3 pulses and the ECU needs to see 300 RPM before the juice to the injectors is turned on by the computer.
Each Jeep is different and what works for one does not promise that it will be the same for the next one.
Keep in mind that the CPS needs to see at least 3 pulses and the ECU needs to see 300 RPM before the juice to the injectors is turned on by the computer.
Each Jeep is different and what works for one does not promise that it will be the same for the next one.
Renix Super Guru
Joined: Mar 2008
Posts: 24,653
Likes: 19
From: In yourz postez fissin jurr spelinzs
Year: 1990XJ/1989MJ
Model: Comanche
Engine: 4.0L Renix
Fuel pressure on the rail would be the first thing to check. Filter may cause it to have reduced power but if it starts eventually it is not the cause of your slow start. Tranny will not have any effect on starting.
Renix Super Guru
Joined: Mar 2008
Posts: 24,653
Likes: 19
From: In yourz postez fissin jurr spelinzs
Year: 1990XJ/1989MJ
Model: Comanche
Engine: 4.0L Renix
You can do it yourself and then you will have the truth. Many dealers try to get you to spend money on repairs that do not need to be done so check it yourself. Go to your favorite parts house and buy a fuel pressure gauge and put it on the schrader valve on the fuel rail.(looks like a fat tire valve with a cap on it) Turn the key on and see what the pressure builds to. (Should be 39+ pounds)
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Renix Super Guru
Joined: Mar 2008
Posts: 24,653
Likes: 19
From: In yourz postez fissin jurr spelinzs
Year: 1990XJ/1989MJ
Model: Comanche
Engine: 4.0L Renix
If you can check the air pressure in your tires then you can do this.
Routine maintainence is the only thing that will keep your Jeep on the road for extended years. Replace failing parts and check everything often.
Routine maintainence is the only thing that will keep your Jeep on the road for extended years. Replace failing parts and check everything often.
Renix Super Guru
Joined: Mar 2008
Posts: 24,653
Likes: 19
From: In yourz postez fissin jurr spelinzs
Year: 1990XJ/1989MJ
Model: Comanche
Engine: 4.0L Renix
Change the tranny fluid no flushing with the AW4. Do the same to the diffs once a year. No matter how many miles you have put on the vehicle. That is probably more than the factory recommended.
Flushing a higher mileage tranny will loosen things that are better left alone. This loosened junk will clog the valve body and thus cause real problems. So change the fluid if you like but DO NOT FLUSH your tranny.
Flushing a higher mileage tranny will loosen things that are better left alone. This loosened junk will clog the valve body and thus cause real problems. So change the fluid if you like but DO NOT FLUSH your tranny.
Renix Super Guru
Joined: Mar 2008
Posts: 24,653
Likes: 19
From: In yourz postez fissin jurr spelinzs
Year: 1990XJ/1989MJ
Model: Comanche
Engine: 4.0L Renix
Flushing gets the microscopic metal shavings out of the gears on the diffs and is not really required. Put a drain pan under the differential. Just pop the cover off of the diff. it will drain out. Clean the mating surface of the cover and the diff. Use a new gasket or a ribbon of RTV sealant. Put the cover back on and refill with the proper fluid as recommended in the owners manual. As for the tranny you can get one of the oil change places to drop the pan and change the filter, clean the two mating surfaces and reinstall the pan with a new gasket. Refill with Dextron IV and no flushing. Impress on them that you do not want it flushed.
BTW three years is to infrequent to have this done. YEARLY is my recommendation.
BTW three years is to infrequent to have this done. YEARLY is my recommendation.
), check this out:http://www.stu-offroad.com/misc/diff-1.htm
It's very simple, as easy as changing oil but a wee bit of cleaning involved. Nothing can be broken during this procedure.



Thanks!