shaner
Junior Member
Posts: 65
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Post by shaner on Jan 20, 2008 17:38:06 GMT -5
I'm sure sooner or later i'll figure this out but you all seem to know your stuff so maybe somebody has been through this. Just recently the 4.0L in my '93 XJ has started stallin' out. At first I just noticed that it would wind down really low when I would come to a stop light and push in the clutch, like down to 500 rpm or so, but then it always bounced back to 1000 and idled like it always had. This all started after i had put in my lift. So now, it just dies, if i pop the clutch in 2nd then it fires right back up and idles fine but it's annoying as fahk. So far i've just tried runnin' it on hightest with fuel injector cleaner and I also pulled the cap off my distributor and cleaned it all up but it looked fine and didn't solve the problem. I'm sort of thinkin' it might be a temperature sensor or something and it could be related to this cold weather but if this scenario rings a bell to anybody and you know the answer i'd love to have it....thanks
Shaner
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Post by lowrad on Jan 20, 2008 17:56:39 GMT -5
I'm thinking maybe it's your TPS....try unpluggin it and see what happens....I had a problem with the Waggy idling at like 1500 plus at sometimes....I unplugged the sencor and messed with the wirring a bit and then plugged it back in....
Sounds like something similar..maybe yours is on it's way out too
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Post by TWISTED on Jan 20, 2008 18:01:23 GMT -5
Couple of things to try..
When its stalls put your foot to the floor..try to start.. Also>>
Try to!!!if you can when it stalls..get under the hood and unhook the Throttle Position Sensor..then rehook it..try the start...if so
Throttle Position Sensor...
Crank Sensor..try to move it..possible you banged it and thru it out abit..
Good luck
StingerXJ
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Post by lowrad on Jan 20, 2008 21:47:25 GMT -5
^^^Stinger got those reversed I think..lol...possible you banged the TPS....unplug like he said(thought I said the same thing...lol..but maybe I confused myself.lol)...Th Crank Sencor is on the tranny and the wiring to it is around your throtle body...try unpluggin that and pluggin it back in...I sometimes have to do that with the Waggy
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Post by wranglerboy on Jan 20, 2008 22:19:13 GMT -5
I've always just unplugged the TPS sensor, and sprayed it out with carb cleaner, and then spray where it plugs in as well. I've done it with the vehicle running and someone revving it up. My old Mustang used to do that, rev between 1500 and 2700 rpm's after a while. Did this trick, and it ran at 475 rpm after that. Constantly!
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Post by fierodude on Jan 20, 2008 23:47:53 GMT -5
i'm not an xj guy but i've heard that the MAP sensor does this on xj's
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Post by lowrad on Jan 21, 2008 5:47:40 GMT -5
Could be MAP sensor...but I've never had to mess with mine(knock on wood)...Mine problems have always been with the TPS and CPS...although to check the MAP...just give it a lite tap witha screwdriver or something and if the engine stumbles...you'll know something is a foot  |
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Post by mellow on Jan 21, 2008 23:23:01 GMT -5
When I had this problem it was TPS too...
EDIT: Then again my brother had a lot of probs with map sensor on his MJ...
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Post by rstarch345 on Jan 22, 2008 17:05:03 GMT -5
That's more a problem with the IAC. The whole point of the IAC is to keep the engine at proper idle. The IAC uses a reference from the TPS to know when to maintain the idle.
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Post by lowrad on Jan 22, 2008 17:59:22 GMT -5
yeah...the IAC works with the TPS but I've never seen one go(well correction...I had to replace one once on a cheby with over 300K on a little V6..)...I would tend to lean towards the TPS...or MAP.....there more common(for god only knows what reason)
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Post by rstarch345 on Jan 23, 2008 9:32:16 GMT -5
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Post by JimmyDodge on Jan 23, 2008 17:34:31 GMT -5
have you tried an upgrade?
maybe a 5.2L Magnum?
TPS - doesn't take much for these things to mess up
IAC - carbon build up on these things can be a problem
last spring I had a similar problem with my truck...
over heating "cat", would make it idle down, I had an issue starting, etc....
I changed plug wires (MSD now) coil (MSD) plugs (3 sets) cap rotor (x2) timing chain &gears, TPS, catylytic converter (Flowmaster, tried 2) plennum gaskets, and FINALLY realized I had a broken wire on an 02 sensor... AAARRRGGGHHH!
changed them both, put in a new battery (battery fixed the stalling, poor idling) and never looked back
good luck man!
electronics SUCK!
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Post by lowrad on Jan 23, 2008 18:03:25 GMT -5
Well Rodney...you may live and breath the XJ..but here's the kicker....MAP WILL affect idle to a certain degree....think about this..if there is a vaccum leak ...and one of the first things to check with the MAP to see if it is gone is to give it a little tap with a screwdriver...if the engine stumbles..then there is a problem...SO if the MAP had nothing to do with the idle then why would the engine stumble
Jimmy is correct that the IAC will carbon up over time...and yes they fail
BUT my first instict when there is a Idle problem with all the sencors to chose from is to chose the sencor that's PRIMARY function is to tell the computer what idle RPM the engine is running at.....
IAC Valvle is only really functioning the most when the engine is going though the stages of being cold to hot....it will allow less air in when cold...and more air in when warm(kinda like a the old fashion choke)...the injectors can only dump in so much fuel when cold or lean out so much when hot so the computer needs another way to control how much air to add to the mix....and as everyone knows...with fuel injection....you step on the gas pedal...your not increasing how much fuel go's in...your increasing how much air....blablabla Lowrad...everyone knows WTF fuel injection does....lol
SO in conclusion....your know further ahead know...lmao...but atleast ya got some new linky's...lol....thanks Rodney....lol
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Post by rstarch345 on Jan 23, 2008 22:23:59 GMT -5
Good points Steve. But hey, I gotta try. Just like two lawyers in a court room. ;D
I'll shut up now and see how things work out.
Steve, how's the other XJ working out?
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Post by lowrad on Jan 24, 2008 5:59:27 GMT -5
Just gotta do the rear deck floors and around the rear inner fenders....I got the rear quarters filled with MonoFoam now so no more crap can get in there...gonna fab up the rocker pieces I need cause they want 80-90 a side for new rockers...and I'm not gona pay that if I don't have too(cause I'm CHEEP ;D)...lol Now Waggy's got a fuel leak of some kind...don't know if it's the injector O rings AGAIN(just did them all last year..around this time)...or if it's a hard line...just smeeled gas last night when I got home..it was idleing for a couple minutes before I shut it down..and I smelled it then    |
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