90 xj running rough please help
#1
90 xj running rough please help
I got a 90 xj on a trade and I love it but when I'm barely on the gas it will sputter and misfire I put new plugs in it did better for a little while but now back to rough but if I get on it it will go plenty of power the egr valve is caped off and a couple other lines are looped it idles fine also
#2
CF Veteran
Joined: Sep 2011
Posts: 4,172
Likes: 4
From: Riviera, Texas
Year: 1998 Sport
Model: Cherokee
Engine: 4.0
When you changed the plugs did you do anything else such as change the cap, rotor and wires? Also what plugs did you put in. Doing half a tune up hardly is worth the time. Just a suggestion, you should run Champion copper plugs gaped at .035. Our 4.0's seem to run better with OEM type of plugs, which are Champion for 1999 and older and NGK for 2000-2001.
#4
I've cleaned the tb and new wires plugs are the champion but it runs great if I get on it it's only when you try and cruise on the highway and hold speed it really does it could it be bad egr since its caped off
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#12
Didn't work anyone have any ideas as to why my xj idles fine runs good when I get on it but if I try to cruse and hold speed it sputters and jerks like a misfire only really does it at mid acceleration or holding speed above 55 any thing under it will hold speed fine but still will miss and sputter at about half throttle
#14
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 19
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Mine dies when I unplug the MAP.
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)
Do go ahead and check the wiring off the injector harness to your lower sensors. Sometimes they "get in trouble". Melt on something hot, rub on things. I did have roughly similar problems with some of mine grounding. SOOO just some things to check/rule out!
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)
Do go ahead and check the wiring off the injector harness to your lower sensors. Sometimes they "get in trouble". Melt on something hot, rub on things. I did have roughly similar problems with some of mine grounding. SOOO just some things to check/rule out!
#15
Senior Member
Joined: May 2012
Posts: 925
Likes: 5
From: Fort Erie, CANADA
Year: 1987
Model: Cherokee
Engine: 4.0
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.
Good luck and be systematic (try one thing at a time).
Also, punctuation helps us old guys read your posts.
wehatehavingtoreadallyourpostslikethiswithoutanyco mmasperiodshyphenscapitalsetc.