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Author Topic: Calling all mechanics my jeep won't start  (Read 959 times)

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Offline Eagle Jeeper

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Calling all mechanics my jeep won't start
« on: March 08, 2010, 06:04:41 PM »
Hey guys my AMC 360 in my CJ  won't start.  I was on the Feb open run and other than the fuel filter plugging it ran great.  I had to yank the filter and buy pass the return line in order to get out of the bush thats the only thing that has been different than usual.   It sat on the trailer for 2-3 weeks and when I went out to start it cranked and cranked with nothing.  I dumped some gas down the carb to get her going because its notorious for draining the bowl dry and it didn't even fire then.  So I brought it into the shop and check that I still had power to the distributer and yes it was good.  I cranked on it a bit more, filled the bowl manually and cranked some more.  It coughed a few times and then ran for a few seconds but didn't sound good or smell good at all.

Any suggestions from here I was thinking I might have to check the timing maybe it bumped in tow I don't know.

Thanks
94 YJj7, AMC360,T176,Dana300(twin stick, Dana 44 4:56, 14 bolt FF welded 4:56, 2 1/2" susp SOA, 38/12.5/15 TSL's, warn 8274,  Custom dash

Offline cLAY

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Re: Calling all mechanics my jeep won't start
« Reply #1 on: March 08, 2010, 06:23:34 PM »
Your fuel filter plugged for a reason. You probably have a bunch of crap in your tank and by removing the plugged filter you allowed all that crap into the carb. That's why the bowl won't fill.

Did it sit for awhile? Did you drive thru deep mud and get water/mud into the fuel tank? Is this its first time offroad in a while...

I'd cut the filter open and see what it looks like, red rusty or dirt/mud? You will mostly likely need to disassemble the carb and clean it as well as drain/flush the tank and lines.

Let us know what you find in the filter, might be worth pumping some fuel into a bottle from the fuel line off the carb and see what it looks like.
..

'93 ZJ, 5.2L, lifted/locked/36s..<gone>
'98 5.9er 4.10s,locked,LA,WJ knuckles

Offline Eagle Jeeper

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Re: Calling all mechanics my jeep won't start
« Reply #2 on: March 08, 2010, 06:34:00 PM »
I agree that the tank should be flushed etc.  But shouldn't it fire when I pour gas down the carb.

I just cut the old filter open it looks pretty clean in my mind white looking element, not rust or mud

Could it be that the fuel pump is on its way out and not able to push through the filter.  When I crank on the motor with the filter unhooked shouldn't the pump be spinning enough to make  fuel come out the hose.  It doesn't.  I might have to revamp my fuel delivery system.  But again shouldn't it run when pouring fuel down the carb.
« Last Edit: March 08, 2010, 07:10:49 PM by Eagle Jeeper »
94 YJj7, AMC360,T176,Dana300(twin stick, Dana 44 4:56, 14 bolt FF welded 4:56, 2 1/2" susp SOA, 38/12.5/15 TSL's, warn 8274,  Custom dash

Offline cLAY

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Re: Calling all mechanics my jeep won't start
« Reply #3 on: March 09, 2010, 09:42:13 AM »
Its pretty unreliable to pour gas down the carb as baically you are flooding it then trying to lean it out by cranking it and hoping its catches when the fuel mixture is right.

You said it coughed so I'm guessing that its firing. You can check by removing one spark plug lead and putting a spark plug in it and laying it across something well grounded and clean. Watch it while some cranks it over and see if it sparks.

You should be getting fuel to the carb when cranking. If you aren't then either the pump is bad or the pump isn't getting fuel(bad line, plugged line, pickup broken off...). 

How much fuel is in the tank? Could the tank be empty and the guage be off? Throw a can of gas in it.

I had a friend with a J20 that had rusty/cracked fuel lines. Occsionally it would suck air and die, took forever to figure out....
..

'93 ZJ, 5.2L, lifted/locked/36s..<gone>
'98 5.9er 4.10s,locked,LA,WJ knuckles

Offline Eagle Jeeper

  • Budget Lift
  • Posts: 286
Re: Calling all mechanics my jeep won't start
« Reply #4 on: March 10, 2010, 12:09:14 AM »
Well upon opening up that filter and finding it clean I unhooked my fuel pump and bench tested it with a vaccum pump and it wouldn't  hold vac so I went and pulled one off a spare motor I have and it seemed to hold great.  Put it in and no more problem.  Thanks Clay for helping out.
94 YJj7, AMC360,T176,Dana300(twin stick, Dana 44 4:56, 14 bolt FF welded 4:56, 2 1/2" susp SOA, 38/12.5/15 TSL's, warn 8274,  Custom dash

Offline cLAY

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Re: Calling all mechanics my jeep won't start
« Reply #5 on: March 10, 2010, 03:34:37 PM »
No problem. I should have thought about the pump first but its been awhile since I've played with a carb/mechanical pump setup.

Smart thinking on pulling a vacuum to check the pump diaphram.

You may want to change your oil. Depending on where the pump diaphram was leaking it could have leaked fuel into your crankcase and diluted your oil. If its overfilled orthe oil smells of gas it needs to be done.

Of course its only $20 for an oil change if its close to being due anyway....
..

'93 ZJ, 5.2L, lifted/locked/36s..<gone>
'98 5.9er 4.10s,locked,LA,WJ knuckles