stalling issue

[Brian Z]

I'm not trying to be rude, but I'm beginning to think my yj has a monthly problem. I pulled up to a red light today and just like I turned the ignition key off, she quit. :shock: Really?? here, now?? thank goodness it was early enough and there was no one else around really. turned the key off, gave it a sec, then turned it. nothing. then gave it a second to think about it, repeat, then it started. went where I had to go, left it running. driving home, hitting some pot holes and bumps, she acted like it was going to do it again for a split sec, then kept right on going, made it home. Its happened before but seriously about every month or so for what reason? It used to happen A LOT! then just wouldn't start one day. called wifey she came got me and went to the parts store and got a coil. put it on, beautiful! no issues. now all of the sudden its starting again. One thing I do know, it takes a while to start. not just turn key, start go, but turn key and let it roll over a bit then , well, ok, ill start put - put vroom. then no issues. I was thinking fuel pump, like every one else here, but why would it quit so quick when it does. I'm thinking electrical. but I'm not sure where to start.
Now there are 2 wires that plug into the coil that have been taped. could they be giving me the issue? I kinda don't wanna retape them or take them apart yet, fear I'll screw something up. I know it may need to go to a shop, but I want to start here with you all first! Any ideas will be tried to day for it is my day to mess with it. kids and wife are at the water park, so its me and YJ today.
thanks in advance.
Z

 

[69jeepcj]

the fuel pump requires a certain fuel presure for the engine to run, so if your pump is going out, but not completly shot yet, you could have low fuel presure. I think its around 55-60 psi.
Its possible that the tapped wires your mentioned could be the problem as well if the wires are corroded or there isnt a good connection. I would start with the wires, just take the tap off and take a look at it, if there is any corrosion or discoloring of the wire I would cut them back an inch or so and reconnect and tape back up. If you only notice it when going over bumps, there is probably a loose connection somewhere.

 

[Brian Z]

Ok I will check the wires. also, this is a 4.0 , how do I check the fuel pressure? what do I need?

 

[69jeepcj]

Most vacum gauges can be used as a presure gauge also. Take your line apart and use one of the fittings that come with the gauge and hook it to the fuel line, try to start the jeep and watch what the gauge shows. the vac gauge comes with a rubber hose and a few fittings for diferent size lines or connections. If your fuel pump is on the side of the engine block take the line apart between the carb and pump, just make sure you are hooking it up after the pump or you will show no presure at all, I say that because I don't know if your pump is in the tank or on the side of the engine.

 

[69jeepcj]

WAIT! Let me correct myself, if your fuel pump is on the side of your engine block then it is a mechanical pump and not a electric pump that the newer ones use, so it would not require high presure to run. If the pump is in the tank then I would check the presure.
Sorry about that, I wasnt thinking for a minute. I am in clearmont cnty, I would offer to help but my tierod end is out in my jeep and the car is on recall.

 

[Brian Z]

wow, I thought I was having a rough day.lol ok . Ill give it a shot. and the fuel line is in the tank. I know its got pressure, but not sure how much. Ill be checkin that. thanks.

 

[69jeepcj]

It could be as simple as a good tune up, plugs, wires, distributer cap if they havn't been changed in a while.

 

[Brian Z]

that tune up was done a 3 months ago, but I did find and issue that really rattled me beyond human intelligence. ill try to post a pic so you can see. the wires that I last described that were taped up, I un taped to find male and female spayed but connectors I guess you call it. but the thing is, they were not put together! they were just on top of one another. so I put them together and re taped them. I quit once of a few big pot holes I went over , but not another problem. ( so far) Fixed a couple vacuum issues, may need a fuel regulator, guy at auto zone who has a yj like mine said the diaghram goes bad after a while. Plus he said knowing it takes a while to crank the jeep over he said it may need a fuel pump soon knowing its not holding the pressure. That I really don't want to dig into...
So this plug goes into the coil. where do the wires go? I was told the distributor? can I get a whole new wire harness with real wires that are not broken and a clip to hold it in place??

 

[69jeepcj]

Im not positive about the wiring on wranglers, but wires coming from the coil usualy do go to the distributer. Cjs have a harness for the engine and one for the interior and tail lights. If you look at where your wiring comes through you firewall, there should be two seperate bundle of wires that plug into a box. If you have the seperate harnesses there, you could go to a junk yard and get a engine harness.