Rokhound Posted July 4, 2007 Share Posted July 4, 2007 Well after 10 months in the shop I fired the MJ up for the first time since I owned it will kind of. What I mean is the truck will run for about 5 sec then die and start right back up for about 5 sec and dies and so on :mad: so whats the deal guys?? Bad fuel filter is the first thing on my list and some fresh gas which I have added. Any thing else I should do to get this thing to stay running. Link to comment Share on other sites More sharing options...
Pete M Posted July 4, 2007 Share Posted July 4, 2007 Check that the wires are connected to the resistor. I thought I had a picture somewhere, but it's a 4" long piece of white ceramic located on the drivers side of the engine bay right on the wall. Link to comment Share on other sites More sharing options...
Rokhound Posted July 4, 2007 Author Share Posted July 4, 2007 Check that the wires are connected to the resistor. I thought I had a picture somewhere, but it's a 4" long piece of white ceramic located on the drivers side of the engine bay right on the wall. thanks pete i went out and all is good there i am going to replace the fuel filter and see what happens Link to comment Share on other sites More sharing options...
Eagle Posted July 5, 2007 Share Posted July 5, 2007 Take the wires off the ballast resister and jumper them together, then try it. What you are describing is the classic symptom of a failed ballast resistor. (That white ceramic block.) The start circuit bypasses it when the key is in the START position, then when you release the key to the RUN position the power goes through the resistor. Quick check -- after it runs and dies out, there's not much pressure in the fuel system. Turn the key to ON (RUN, not START). Do you hear the fuel pump running? It should run for about 5 seconds, until the fuel rail is pressurized. If you don't hear the fuel pump -- the resistor isn't allowing power to the fuel pump. Link to comment Share on other sites More sharing options...
offroader461 Posted July 5, 2007 Share Posted July 5, 2007 my MJ doesnt have that ceramic block there...never has since i bought it 4yrs ago...do i need this or not??? Just wondering...i was at my local j/y and was diggin through the comanche they had there and saw that and wondered if i should take it and install it on mine>> Link to comment Share on other sites More sharing options...
Rokhound Posted July 5, 2007 Author Share Posted July 5, 2007 Take the wires off the ballast resister and jumper them together, then try it. What you are describing is the classic symptom of a failed ballast resistor. (That white ceramic block.) The start circuit bypasses it when the key is in the START position, then when you release the key to the RUN position the power goes through the resistor. Quick check -- after it runs and dies out, there's not much pressure in the fuel system. Turn the key to ON (RUN, not START). Do you hear the fuel pump running? It should run for about 5 seconds, until the fuel rail is pressurized. If you don't hear the fuel pump -- the resistor isn't allowing power to the fuel pump. That is great info guys thanks. This what lead me to thank that the fuel pump was bad but be for i drop the tank i thought i would take the fuel line off and see if I was getting gas to the motor I was but I was not hearing the fuel pump so tonight after work I will try this and one more thing to do i need to replace it or not Link to comment Share on other sites More sharing options...
87manche Posted July 5, 2007 Share Posted July 5, 2007 my MJ doesnt have that ceramic block there...never has since i bought it 4yrs ago...do i need this or not??? Just wondering...i was at my local j/y and was diggin through the comanche they had there and saw that and wondered if i should take it and install it on mine>> 87's didn't have it, put in starting 88 to quiet the pump. Link to comment Share on other sites More sharing options...
Rokhound Posted July 5, 2007 Author Share Posted July 5, 2007 that was the deal guys thanks now one more question does some one no what size o-ring the main fuel line takes thanks watson Link to comment Share on other sites More sharing options...
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