From owner-xj-digest-at-digest.net Fri Feb 10 22:27:00 2012 From: xj-digest To: xj-digest-at-digest.net Date: Sat, 11 Feb 2012 06:26:56 +0000 Subject: xj-digest V1 #3359 xj-digest Saturday, February 11 2012 Volume 01 : Number 3359 Forum for Discussion of XJ cherokees and wagoneers Brian Colucci Digest Coordinator Contents: RE: xj: Re: [WJ-Grand] Rpm surging xj: Re: fsj: New to me 4.0 for J10? XJ Digest Home Page: http://www.digest.net/jeep/xj/ Send submissions to xj-digest-at-digest.net Send administrative requests to xj-digest-request-at-digest.net To unsubscribe, include the word unsubscribe by itself in the body of the message, unless you are sending the request from a different address than the one that appears on the list. Include the word help in a message to xj-digest-request to get a list of other majordomo commands. ---------------------------------------------------------------------- Date: Fri, 10 Feb 2012 00:07:02 -0500 From: Mark Zupan Subject: RE: xj: Re: [WJ-Grand] Rpm surging This sounds way familiar. Afew months ago, I worked on a Grand Cherokee with similar symptoms. Wound up being a bad TPS. I hooked up a scanner & observed the data while my cohort jiggled wires under the hood. Saw the TPS percentage going bonkers, replaced it, & voila!. Hope this points you in the right direction. Mark > Subject: xj: Re: [WJ-Grand] Rpm surging > To: WJ-Grand-at-yahoogroups.com; xj-at-digest.net > From: fullsizejeeps-at-gmail.com > Date: Fri, 10 Feb 2012 02:57:11 +0000 > > Any codes? > Do you know how to read them without a device? I think it's on my sever. > > 3 times on/off. Reads out on the odo. > > Suspect tps or maybe cps. > > John > __john_at_http://wagoneers.com__ > > -----Original Message----- > From: David Bierschank > Sender: WJ-Grand-at-yahoogroups.com > Date: Thu, 9 Feb 2012 20:12:20 > To: ; Xj-at-Digest.Net > Reply-To: WJ-Grand-at-yahoogroups.com > Subject: [WJ-Grand] Rpm surging > > I have a 2000 WJ 4.7 quadra-drive with 95000 miles. When sitting at idle the rpm is very unstable. It will start out around 750 or so then surge up close to 1500 then back down. Idle seems a little rough but not too bad other than the surging. > > It will continue to do this as long as you will allow. Seems to me kind of like a vacuum leak on an older car. Other things that come to my mind are map sensor, throttle position sensor. > > As sit here writing this it stumbled badly just below 500 then quickly shot to 1500 then settled back in around 750. > > Any ideas or input would be appreciated. > > David Bierschank > > Sent from my iPhone > <*> To visit your group on the web, go to: > http://groups.yahoo.com/group/WJ-Grand/ > > <*> Your email settings: > Individual Email | Traditional > > <*> To change settings online go to: > http://groups.yahoo.com/group/WJ-Grand/join > (Yahoo! ID required) > > <*> To change settings via email: > WJ-Grand-digest-at-yahoogroups.com > WJ-Grand-fullfeatured-at-yahoogroups.com > > <*> To unsubscribe from this group, send an email to: > WJ-Grand-unsubscribe-at-yahoogroups.com > > <*> Your use of Yahoo! Groups is subject to: > http://docs.yahoo.com/info/terms/ ------------------------------ Date: Fri, 10 Feb 2012 22:26:43 -0800 (PST) From: john Subject: xj: Re: fsj: New to me 4.0 for J10? I went through this exercise about 11 years ago... the 4.0L will be fine, especially with 3.54 gears and 31's. here's the specs... the 4.0 in '99 morphed 1/2 way through the year when it went to individual coils, that's when the head woes started... otherwise they're fine... You'll get better mileage for sure. I wonder if I shouldn't find a 4.0 for my '83 J10 long bed, that 360 is a pig. only problem is it has 2.72 gears... ughhh... year - engine - HP -at- rpm - torque -at- rpm - -------------------------------------- 83 - J10 4.2L - 115 hp -at- 3,200 - 210 ft lbs -at- 1,800 <-- original 97 - ZJ 4.0L - 185 hp -at- 4,600 - 220 ft lbs -at- 2,400 99 - WJ 4.7L - 235 hp -at- 4,800 - 295 ft lbs -at- 3,200 <-- WJ 99 - WJ 4.0L - 195 hp -at- 4,600 - 230 ft lbs -at- 3,000 83 - J10 360V8 - 129 hp -at- 3,700 - 245 ft lbs -at- 1,600 <-- Old Blue 88 - XJ 4.0L - 177 hp -at- 4,500 - 224 ft lbs -at- 2,500 <-- little wagoneer 91 - XJ 4.0L - 190 hp -at- 4,750 - 225 ft lbs -at- 4,000 john ----- - ------------------------------------------------------------------------ -o|||||o- fahrvergnugen y'all - please reply to: john-at-wagoneers.com Snohomish, Washington - where Jeeps and VWs don't rust, they mold http://AMSOIL.com/redirect.cgi?zo=283461 TRSTGZS http://JohnMeister.com HTTP://WAGONEERS.COM http://fotomeister.us - ------------------------------------------------------------------------ On Fri, 10 Feb 2012, Landon Tesar wrote: # Hi all, # # You've probably been following that I have a tired 258 in my J10. I drove it # about 70 miles and it blew about 1/2 a quart of 20W-50 in various directions # (rear main seal, blowby into the air intake, and i *think* it may be leaking # out of the plastic hose for the mechanical oil pressure guage at the # compression fitting, but only after everything gets hot. I should run it up # to temp and then find out.... # # Anyway, I found a '98 4.0 in a Cherokee that needs a new home. It's had 120K # easy miles and looks really good. I get the flywheel, the starter, the # intake and exhaust manifolds, the alternator and power steering and water # pump, and hey, 6 qt oil pan? Looks really clean. $500 seems like a deal # when I paid 250 for a 258 core to scrounge stroker parts. # # So had the 258 crank turned, and installed new crank and rod bearings in it, # awaiting a 4.0 head. But this 4.0 is so clean, I could stroke the 4.0 with # the 0630 head, or just drop the 4.0 in the way it is. # # Questions: # # Does a stock '98 4.0 have torque in the right place for a J10 with 3.54 # gears, T18, and 31" tires to get up and down the road? (The 258 right now is # really a slug) # Would a stroker with ported head and probably a small (read Crower 44243) # camshaft replacement and compression ratio increase make a *needed* # difference ? # Nothing to tow right now, just some light 4x4 on the beach. # # Cam + lifters -> $200 # Valve Job and Port -> $300 # Pistons and rings -> $200 # Align hone/Deck/Bore/Hone cylinders -> probably $400 by the time it's done. # Press piston pins / new rod bolts / some assembly at machine shop -> $200 # # Ouch, I think I just answered the question. # # Please let me know what you think. I don't want this 4.0 to be a high-end # motor where I'm just in the low vacuum range all the time. I think the T18 # helps here. # # - Landon ------------------------------ End of xj-digest V1 #3359 *************************