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Misfiring 4.0

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Old 01-12-2020 | 06:03 PM
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David Ring's Avatar
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Default Misfiring 4.0

It started as rough acceleration but it has gotten to where it will drive fine for about 2 minutes(gauged in time not miles because I do some slow mud crawling leaving my home) then start to misfiring through intake and exhaust,turn key off start back up does another 2 mins and then just starts getting less and less drive time till it finally just wont drive only misfire when you hit gas.I have replaced tps, cleaned throttle boddy and iac,new map sens,
plugs,wires,cap and rotor, 3x fuel pump finally settled with carter by the time I decided that was not the problem. New coolant temp sensor. I'm down to thinking distributor or computer guide me if I'm wrong. This forum has been an absolute god send since I bought my baby it wouldn't be running at all if it weren't for someone's clear picture of the o2 sensor wire shorting out on the exhaust. Wish I could give true cred to that user but it's been almost a year now.thanks everyone in advance I'm losing my mind as it is my dd.
Old 01-12-2020 | 09:01 PM
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Test your crank sensor and your cam sensor, and your coil. They are famous for failing when hot.

Say, you aren't the famous David Ring, are you?


Old 01-13-2020 | 06:54 AM
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And, if your coil says Magnetti Marelli on it, replace it.
Old 01-13-2020 | 10:35 AM
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Test for compression and occluded exhaust.
Old 01-13-2020 | 10:02 PM
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No I wouldn't be that david ring lol and I have done the coil as well as the crank sensor 2x first time drippped the bolt got lucky and pulled through dust cover but second time lost socket and knuckle, life lesson check your tools and I figured I'd just go ahead and replace the distributor and cam sens at once since I'd have to pull the whole thing anyways and it is 20 years old or so also on exhaust I do hear that rattling quite a bit any suggested place to get entire exhaust?headers and all
Old 01-13-2020 | 10:03 PM
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Oh and I got the socket out through the starter hole finally with much work thanks to yet another amazing posts advice from this forum
Old 01-18-2020 | 10:34 AM
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Well status update I did just replace the distributor from oriely never again, came with one side for cap screw completely stripped and ready for nut and bolt lol, drove through mud and what do you know,starts misfiring front and back then dies I did note fuel pump was pretty loud before dying so I checked cap on tank it had a little pressure so I tried again with it barely screwed in but no difference . I guess it's a computer next and then back for exhaust and o2 sens
Old 02-15-2020 | 09:28 PM
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Just cleaned entire fuel system including injectors,ravaged a good testing crank Sens from jy,and still about 1 minute drive time,pump starts whining,then it starts sputtering and shuts down could I run a direct 12 volts to pump and put it on a switch or would it even help?
Old 02-15-2020 | 09:34 PM
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Sorry to keep bumping but I need this dang thing for work, also installed brand new computer so it's not that either
Old 02-15-2020 | 11:22 PM
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bypass the fuel pump ballast resistor.


Old 02-16-2020 | 07:46 AM
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Originally Posted by cruiser54
bypass the fuel pump ballast resistor.

PREV owner went ahead and beat me to that one I even opened up the looming that area to look for a bad splice or anything but couldnt find any,this is like chasing my tail around in circles working on this thing.
Old 02-16-2020 | 07:55 AM
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I'm on my third crank sens now 1st was knock off of course,second one was mopar in jeep dodge Chrysler sealed bag but marked"made in mexico"?wtf? And third one I just put in I tested off an old jeep at my jy but it changed nothing I'm so confused
Old 02-16-2020 | 09:05 AM
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Know how to use a multimeter?

How much voltage do you have at the pump and how good id the ground to it/
Old 02-16-2020 | 10:28 AM
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Originally Posted by cruiser54
Know how to use a multimeter?

How much voltage do you have at the pump and how good id the ground to it/
so I just back probed the connector while running and the voltage stays at a steady 11.26 while running and then the pump started whining and then it basically acted like it ran out of gas I pulled these codes this morning:12,35,76,33,55
I dont have an e fan so I'm sure that's what 35 is but 76?
Old 02-16-2020 | 10:36 AM
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Originally Posted by David Ring
so I just back probed the connector while running and the voltage stays at a steady 11.26 while running and then the pump started whining and then it basically acted like it ran out of gas I pulled these codes this morning:12,35,76,33,55
I dont have an e fan so I'm sure that's what 35 is but 76?
The ground?


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