kbusch18 Posted October 27, 2012 Share Posted October 27, 2012 Hey I have been trying to this problem for a long time my jeep will turn over start then shutoff it will stay in that cycle if I keep the key turned So far I have changed Fuel pump fuel filter icm coil fuel pump relay ballast resistor ignition switch and ecu. Any thoughts Link to comment Share on other sites More sharing options...
Eagle Posted October 28, 2012 Share Posted October 28, 2012 That's usually what happens with a bad ballast resister. have you tried bypassing it, or hot-wiring the fuel pump? Link to comment Share on other sites More sharing options...
kbusch18 Posted October 28, 2012 Author Share Posted October 28, 2012 I have changed both fuel pump and ballast resistor I have also bypassed the resistor Link to comment Share on other sites More sharing options...
cruiser54 Posted October 28, 2012 Share Posted October 28, 2012 Are you sure it was the fuel pump relay you changed? There's more than one inaccurate schematic for the relays. Should be 2nd one back from the front. Link to comment Share on other sites More sharing options...
kbusch18 Posted October 28, 2012 Author Share Posted October 28, 2012 for the relay i replaced the 2nd one from front when that didnt change anything i went through each with the new relay and no luck is there anything i am overlooking i know a map sensor wouldnt cause it not to start it makes me feel like there is a fuse or another relay because there is never any variance in the symptoms Link to comment Share on other sites More sharing options...
Eagle Posted October 28, 2012 Share Posted October 28, 2012 for the relay i replaced the 2nd one from front when that didnt change anything i went through each with the new relay and no luck is there anything i am overlooking i know a map sensor wouldnt cause it not to start it makes me feel like there is a fuse or another relay because there is never any variance in the symptoms Wait -- in your first post you said it starts but won't stay running. If it starts, it has fuel pressure when cranking. Run a jumper wire (at least a 14-gauge or 12-gauge) directly from the battery to the hot side of the fuel pump, then start it and see if it stays running. Or just turn on the ignition and use a 12-volt test light or multimeter to probe the wire feeding the fuel pump to see if it is getting electricity. Link to comment Share on other sites More sharing options...
kbusch18 Posted October 28, 2012 Author Share Posted October 28, 2012 what would that narrow it down to ill try it once sandy leaves and let ya know Link to comment Share on other sites More sharing options...
Eagle Posted October 29, 2012 Share Posted October 29, 2012 what would that narrow it down to ill try it once sandy leaves and let ya know I'm sure there's a question in there somewhere, but I'll be danged if I can figure out what you're asking. I don't mean to sound crotchety, but I AM a crotchety senior citizen. The English language uses capital letters, punctuation, and sentences so other people can understand what you're writing. Try it -- it'll help immensely. Link to comment Share on other sites More sharing options...
cruiser54 Posted October 29, 2012 Share Posted October 29, 2012 You mean like this? Yesterday, I helped my Uncle Jack off a horse. Versus: Yesterday i helped my uncle jack off a horse Link to comment Share on other sites More sharing options...
kbusch18 Posted October 29, 2012 Author Share Posted October 29, 2012 Missed a coma my bad bud Link to comment Share on other sites More sharing options...
kbusch18 Posted October 29, 2012 Author Share Posted October 29, 2012 What would that narrow it down to, ill try it once sandy leaves and let you know Link to comment Share on other sites More sharing options...
cruiser54 Posted October 29, 2012 Share Posted October 29, 2012 See if you have 12 volts to the pump, at the pump. Also, there is a critical ground for the fuel pump behind the left taillight. Link to comment Share on other sites More sharing options...
kbusch18 Posted October 29, 2012 Author Share Posted October 29, 2012 so when the fuel pump primes up initially it should show 12v, should i also check it while turning over the engine, would that provide any insite Link to comment Share on other sites More sharing options...
cruiser54 Posted October 29, 2012 Share Posted October 29, 2012 Yes, it would. Orange wire at the fuel pump. Link to comment Share on other sites More sharing options...
HOrnbrod Posted October 29, 2012 Share Posted October 29, 2012 You mean like this? Yesterday, I helped my Uncle Jack off a horse. Versus: Yesterday i helped my uncle jack off a horse :rotfl2: Good one. :rotfl2: Link to comment Share on other sites More sharing options...
kbusch18 Posted November 14, 2012 Author Share Posted November 14, 2012 no dice on the volt meter checks out at 12v Link to comment Share on other sites More sharing options...
maddzz1 Posted November 15, 2012 Share Posted November 15, 2012 I had this same problem on my 89. It was a bad wire going to the starter relay near the fusible links. Link to comment Share on other sites More sharing options...
Harley Posted November 15, 2012 Share Posted November 15, 2012 Did ya feed the gerbils? Sometimes they get lazy when not properly fed...... Link to comment Share on other sites More sharing options...
ParadiseMJ Posted November 16, 2012 Share Posted November 16, 2012 So that's why my Uncle's horse is always so happy :yes: I'd second the ground wire behind the taillight. The FP shares the ground with the tail harness. A loose ground and funky trailer wiring gave me fits when I first got my MJ. I don't know if the same ground is there on my XJ. I didn't even know about the ground back then. Link to comment Share on other sites More sharing options...
Eagle Posted November 16, 2012 Share Posted November 16, 2012 So that's why my Uncle's horse is always so happy :yes: I'd second the ground wire behind the taillight. The FP shares the ground with the tail harness. A loose ground and funky trailer wiring gave me fits when I first got my MJ. I don't know if the same ground is there on my XJ. I didn't even know about the ground back then. ??? It starts when the key is in the START position, so the fuel pump must have a ground. The problem is that he's getting power to the fuel pump through the starting bypass circuit, but the fuel pump is NOT getting power when the key is in the RUN position. So how do we trouble-shoot that? For openers, although the ballast resistor has been replaced and then by-passed, I saw no mention of testing the circuit. You've got two nice, big, fat contacts there so I would begin by putting the key in the RUN position and check to see if you have 12-volts at the ballast resistor. (Actually, it'll be 12-volts on the upstream side, and something like 8 or 9 volts on the downstream side.) If you have power at the ballast resistor, then look at the wire from there to the fuel pump. If you don't have power at the ballast resistor input side, then trace back upstream from there. Link to comment Share on other sites More sharing options...
kbusch18 Posted November 17, 2012 Author Share Posted November 17, 2012 Okay took a voltmeter to every wire on the starter relay checked fusible links as well everything checks out with the key in both the on and start positions. i did notice that when the truck attempts to fire up the coil wire to the distributor is topping out at .7v is that common. and i have two grounds for the fuel pump Link to comment Share on other sites More sharing options...
maddzz1 Posted November 17, 2012 Share Posted November 17, 2012 With my truck, I would turn the key to START and the truck would start, but when I released the key back to RUN it would die. If I held the key forward in the START position the truck would stay running. Is this what your truck is doing? If so, I know it was one of the wires at the starter relay with a ring connector on it. I think it was orange. I couldn't find the problem and eventually brought to a little shop that specializes in auto electrical and they found the problem. Link to comment Share on other sites More sharing options...
kbusch18 Posted November 17, 2012 Author Share Posted November 17, 2012 No if I keep the key in the start position it will continue to attempt to start goes in a cycle until I release the key Link to comment Share on other sites More sharing options...
maddzz1 Posted November 18, 2012 Share Posted November 18, 2012 What happens if you put some gas in the throttle body and start it? Maybe your IAC is stuck holding the flap closed in the throttle body? Link to comment Share on other sites More sharing options...
cruiser54 Posted November 18, 2012 Share Posted November 18, 2012 What happens if you put some gas in the throttle body and start it? Maybe your IAC is stuck holding the flap closed in the throttle body? That can't happen. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now