I have a '90 Comanche 4.0 inline six with a five-speed manual (170,000 mi)and have been having some problems. Until the past couple weeks, I've never had a single issue with the truck at all. When traveling on the interstate in 5th gear, my engine will jerk and RPM falls but only for a second. It happens every few minutes. In addition, when decelerating (for example, slowing down for a stoplight) my engine simply dies and I have to restart. I just changed my plugs and plug wires, replaced the fuel filter, and air filter. Any suggestions would be much appreciated.

 

comanches have different fuel pumps from cherokees. maybe try comanchclub.com

check the balast resistor by jumpering it... that ceramic deal on the driver inner fender

 

sounds alot like what my Jeep did when the pre-filter on the pump got really clogged. Check your fuel pressure. that would be the one sure way to see if the pump is going out

 

On the Comanche fuel pumps there is a rubber hose in the tank that goes from the fuel pump to the out put hose. Many times this hose dryrots and will cause the symptoms that you are experiencing. IT also could be the first signs of your fuel pump going bad.

The easiest way way to change this is to use as much fuel as possible out of the tank.
1.Jack up the rear and support on the axles or frame, which ever gives you more room.
2.I recommend removing driveshaft.
3. take a screw driver and gently tap retaining ring around.
4. carefully remove fuel pump assembly.
5. replace hose/fuel pump.

I strongly recommend making sure you replace fuel pump, and make sure you have a gas tank o-ring.

This is one of those jobs I actually get estimates on to have done. After doing it once... I pay to have it done.