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90 xj running rough please help

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Old 04-06-2013 | 10:37 AM
  #16  
cruiser54's Avatar
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Year: 1990
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Originally Posted by 67 GMC
I'd check the fuel pump pressure on the rail too. Just before my pump went, it would idle fine but the pressure would drop / become erratic when I gave it some constant throttle. Look at Cruiser's book of wisdom of course. Can't do anything until you go through the tried and true advice found there.

Good luck and be systematic (try one thing at a time).

Also, punctuation helps us old guys read your posts.

wehatehavingtoreadallyourpostslikethiswithoutanyco mmasperiodshyphenscapitalsetc.
Yesterday, I helped my Uncle Jack, off a horse.

Read that disregarding punctuation and see how the meaning changes.....
Old 04-06-2013 | 11:47 AM
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Cruiser, you're a dirty old man
Old 04-06-2013 | 11:54 AM
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Sorry guys I'm not the brightest bulb in the bunch I'm trying I do good just getting everything spelled correctly
Old 04-06-2013 | 11:57 AM
  #19  
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. , ? ! ' : - " / . ,

^Ever seen or heard of these things above?
Old 04-06-2013 | 11:59 AM
  #20  
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you can almost certainly rule out iac if its idling fine. iac does exactly what its called idle air control. you said something about one plug looking like it got hit? was it a new plug? did u regap it and stick it in? did you recheck? also post a picture if it was an old plug.
Old 04-06-2013 | 12:25 PM
  #21  
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Originally Posted by 1996sportXJ
. , ? ! ' : - " / . ,

^Ever seen or heard of these things above?
Where di dyou find those? Whaddya gonna do wif em.
Old 04-06-2013 | 12:54 PM
  #22  
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Year: 89
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Originally Posted by cruiser54
Yesterday, I helped my Uncle Jack, off a horse.

Read that disregarding punctuation and see how the meaning changes.....
Possible new bumper sticker........
Old 04-06-2013 | 08:25 PM
  #23  
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The plug was smashed no gap at all. It's like the piston slapped it I threw it away when changing plugs so no pic I've done the whole ground refreshing and electrical connections under the hood look fine and I cleaned them with contact cleaner no luck yet though
Old 04-06-2013 | 10:41 PM
  #24  
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Year: 1993
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Engine: 4.0 HO
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It took 3 years to figure out my '90 gremlin .. sounds just like yours

was (-) battery cable to block .. oil soaked wet noodle .. never realized it because it was in that protective duct .. oil leak from filter adapter dripped directly into that duct

replaced cable .. all good

I replaced all kinds of stuff before that too .. $$$$$$ .. cable was free from scraps at work

its a renix? if so, did you replace the funky octopus lookin vacuum harness yet? mine had leaks galore .. dirty dirty inside .. new part wasn't too cool either .. hoses kept coming apart .. glued / taped / zip tied them tight

Last edited by dogkatcher; 04-06-2013 at 10:46 PM.
Old 04-06-2013 | 10:44 PM
  #25  
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Engine: 4.0,2.5
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Originally Posted by DFlintstone
In ether in my, or Cruisers signature you will find info on adjusting that new TPS. You might start by getting that handled...You will need a digital meter. Even the cheap $4 Harbor Freight ones work, at least for a while.
It only takes a couple minutes to check the CPS, rule that out....that darn trickster thing can do about anything! (like a condensers use to)
I take the time to add punctuation, as a matter of respect to the reader. I can just spill something and let them try to figure it out, or make it easier, as in those last three commas. (and the period). Like riding a bike! You can get it! Then, use, to many commas, like me!

I'd go ahead and adjust that TPS, gotta do it anyway. Unplugging the IAC just leaves it where it was..As said, likely not your problem.

As RT points out in post 2, did you gap your plugs to .035? New doesn't mean right. I'm cheap, I don't often buy rotors and caps. Scrubbed in the kitchen sink, and good and dry seems to work. Granted, it's hard to see a black carbon track on a black dizy cap though!

Spark might try to find another way, or just not make it across the gap at all under high compression. If it's is crisp and blue, it is most likely finding another way, or jumping the gap, (as intended)

So, plug gap, (& cap/rotor), adjust TPS, and the fuel pressure....does it always go like heck if you floorboard it?

Just my .o2!

Last edited by DFlintstone; 04-06-2013 at 10:55 PM.
Old 04-06-2013 | 10:53 PM
  #26  
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Originally Posted by dogkatcher
It took 3 years to figure out my '90 gremlin .. sounds just like yours was (-) battery cable to block ..
Agreed! Just checking the resistance of the grounds ....smart. I have stuff Crusier wrote on that in my signature...it's in his as well......
Old 04-07-2013 | 12:51 AM
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I replaced the vacuum harness with all new lines, but without the egr valve hooked up. When I hooked the egr up right it just kept stalling out, the plugs are gaped right. No oil all my grounds are clean and nice and tight.
Old 04-07-2013 | 12:53 AM
  #28  
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Also yes if I floor it it will get up and go no sputter or anything
Old 04-07-2013 | 06:44 AM
  #29  
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Originally Posted by bigRyan1127
I replaced the vacuum harness with all new lines, but without the egr valve hooked up. When I hooked the egr up right it just kept stalling out, the plugs are gaped right. No oil all my grounds are clean and nice and tight.
Clarify please. Clean and tight or did you remove, scrape, sand, polish til shiny?
Old 04-07-2013 | 08:42 AM
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Removed and cleaned, I did you're ground refreshing. I'm out of work right now so I've had nothing but xj time lol


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