jcComanche86lb Posted October 30, 2011 Posted October 30, 2011 My Manche quit running last night while I was warming it up and now it won't stay running. It starts and revs up to about 1200 rpm then shuts off. I can smell gas and it looks like the inside of the throttle body is saturated with gas. I do have spark so I'm thinking possible fuel pressure regulator, has anyone else had this problem?
jcComanche86lb Posted October 31, 2011 Author Posted October 31, 2011 I found that the fuel pump only runs while I am starting the engine. Does anyone know if there is a fuel pump relay or does someone have a schematic?
mule13 Posted October 31, 2011 Posted October 31, 2011 should be one of the relays on the passengers side fender well under the hood. should be 3 in a row there. i can't remember which is which. google comanche fuel pump relay may get something also theres a balast relay thing on the drivers fender.its like ceramic with a wire on both ends if the wire gets knocked off it won't start. actually it will start then die instantly. i googled it and theres a thread on jeepforum about them also had pictures of them i guess theres 4 relays there it showed fuel relay as 3rd from left but i don't know what eng/tranny setup that was and what you have.
ComancheKid45 Posted October 31, 2011 Posted October 31, 2011 Jump the 2 wires that connect to the Ballast resister (inside drivers fender, under the hood) and your problem should be solved....definently sounds like a Ballast Resistor issue ;)
jcComanche86lb Posted November 3, 2011 Author Posted November 3, 2011 I have looked but I don't think I have a ballast on mine its a 1986 2.5. I've swapped relays around with no change. I also replaced the starter relay and no change. :dunno: I'm starting to think it's the fuel pump but still need to check if it is getting power. The fuel pump should run if the key is on right?
maddzz1 Posted November 3, 2011 Posted November 3, 2011 I have looked but I don't think I have a ballast on mine its a 1986 2.5. I've swapped relays around with no change. I also replaced the starter relay and no change. :dunno: I'm starting to think it's the fuel pump but still need to check if it is getting power. The fuel pump should run if the key is on right? You are correct, an 86 doesnt have a ballast resistor. Turn the key to run, not start, and you should hear the fuel pump kick on. Get a fuel pressure gauge and test the pressure at the rail.
jcComanche86lb Posted November 4, 2011 Author Posted November 4, 2011 I checked the voltage at the fuel pump connector and I only get 12v if the key is in the start position. It's tbi so in don't have a fuel rail but I am going to check at the fuel filter. Is there some sort of fuel shut off in case of a rollover? I hope this doesn't lead back to my ECM. Thanks for the help so far hopefully I can get it going by this weekend.
jeepdoc Posted November 4, 2011 Posted November 4, 2011 check for poss loose ground wire near the ebrake pedal usually the ground was mounted to a ground screw behind the kick panel on drivers side. usually 2 or 3 black wires with an eyelet
maddzz1 Posted November 4, 2011 Posted November 4, 2011 Also check for a loose or broken wire between the battery and power dist center where the fusible links are located. I have seen this be the problem with fuel issues a few times.
DIGMYGP Posted November 4, 2011 Posted November 4, 2011 This same symptom was happening to an XJ the fix was a vacuum line was leaking
jcComanche86lb Posted November 6, 2011 Author Posted November 6, 2011 Well turns out to be the fuel pump, is there anywhere to find a better price for one than local parts stores? Any tips or anything I should know before changing it?
jcComanche86lb Posted November 11, 2011 Author Posted November 11, 2011 Well I found the culprit. It goes from the fuel pump to the steel tube that comes out of the tank. It had to have been leaking since it got the jeep because once I replaced it the jeep ran stronger than ever. And i was able to take the fuel pump back to vato zone thanks for all the help guys.
Eagle Posted November 11, 2011 Posted November 11, 2011 The fuel pump should run if the key is on right? Not necessarily. It runs only until it builds pressure, then it shuts off. So where is that tube you replaced? Inside the tank?
jcComanche86lb Posted November 11, 2011 Author Posted November 11, 2011 Yes it was in the tank. It didn't completely break until I put fuel system cleaner in it.
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