BBCchris Posted March 30, 2009 Share Posted March 30, 2009 Well I finally got my '89 2.5 5spd 2WD SB Comanche back after a 4 year seperation. A buddy needed it, so I sold it to him and then it got passed around to several other owners like a $2 lady of the night.... anyway, I found her sitting in a field all sad and a bit more ragged than the last time I saw her. Well I hopped in and it started right up but the idle sored around 3000-3500 for a few minutes and then settled down to where its supposed to be. So, off I go and start the drive back home and can't get it above 35mph, anymore than than and it falls right on it's @$$ and starts spitting and spuddering but never dies. When you do a cold start it seems fine for a few minutes and if you wait you can hear how the idle changes and become rough. I'm sort of jumping the gun because I just did a really quick look at the engine and didn't pull out the multi-meter yet to check sensors. I did notice that the cat has been removed and there is a new O2 sensor. I did have some problems years ago with a leaky MC that crapped fluid on the fuse block but everything seems to be ok in that area. Any thoughts on where to start? Plans for it.... I got a doner 94 XJ, so she's getting the six, auto and 4WD stuff. Specs- '89 2.5, 5spd, 2WD, SB 97+ Clip, has been on it for 5 years 97+ seats, full console and carpet. No rust on the floors! Solid body. -Chris And I'll post some pics of it when I get home tonight. :brows: Link to comment Share on other sites More sharing options...
Geonovast Posted March 30, 2009 Share Posted March 30, 2009 How long was it sitting? Syphon the gas and replace it with fresh. Link to comment Share on other sites More sharing options...
BLHTAZ Posted March 30, 2009 Share Posted March 30, 2009 How long was it sitting? Syphon the gas and replace it with fresh. :agree: That was my first thought too. Bad gas or clogged fuel filter...maybe both. Start simple - be sure you have good gas, and it is getting to the motor unrestricted. Link to comment Share on other sites More sharing options...
BBCchris Posted March 30, 2009 Author Share Posted March 30, 2009 It's only been sitting there for a month. Last owner bagged it after it started falling on its butt at 35mph. I agree with the fuel problem, but would it also do it just sitting there at idle? I can see it being the filter and doing that at speed.... Link to comment Share on other sites More sharing options...
project88mj Posted March 30, 2009 Share Posted March 30, 2009 the reason you have no power is ........its a 2.5 do the 4.0 swap asap Link to comment Share on other sites More sharing options...
BBCchris Posted March 30, 2009 Author Share Posted March 30, 2009 the reason you have no power is ........its a 2.5 do the 4.0 swap asap I know, I know..... I drove it stock for years with the 2.5 and it's not that bad you just gotta be willing to row it between the gears....... lot's and lot's of rowing :shake: And yes I'm going to swap it out asap but would like to use it to haul parts and doing yard work before she goes under the knife. Link to comment Share on other sites More sharing options...
Geonovast Posted March 30, 2009 Share Posted March 30, 2009 the reason you have no power is ........its a 2.5 do the 4.0 swap asap The 2.5 isn't completely useless. If it's running properly it makes a good DD, and with good gearing it can carry some weight in the bed. Granted, I've never driven a TBI 2.5, but my MPFI 2.5 on 3.55 gears and 205/75/R15s will do 90 easy enough. On flatish ground I can even use 5th. Link to comment Share on other sites More sharing options...
Pete M Posted March 30, 2009 Share Posted March 30, 2009 Timing belt? Link to comment Share on other sites More sharing options...
BBCchris Posted March 30, 2009 Author Share Posted March 30, 2009 I wouldn't think so, I guess I'll be doing some digging tonight. To me it seems to be lacking fuel under load. Sitting in the garage it will rev up fine... just not under load. The high idle at cold start up had me thinking TPS which might make it fall on its face driving if it lost contact. Link to comment Share on other sites More sharing options...
project88mj Posted March 31, 2009 Share Posted March 31, 2009 try the tps first then the filter then the pump Link to comment Share on other sites More sharing options...
JeepcoMJ Posted March 31, 2009 Share Posted March 31, 2009 clean your fuel filter. then swap your injector. my bet, your fuel system is just gummed up. after those two things, there is the TPS, CPS, and ICM (coil pack) Link to comment Share on other sites More sharing options...
Eagle Posted March 31, 2009 Share Posted March 31, 2009 Timing belt? Pete, have you gone over to the dark side? Timing "belt"? In an MJ? The 2.5L uses the same silent roller timing "chain" that the 4.0L does. Link to comment Share on other sites More sharing options...
Pete M Posted March 31, 2009 Share Posted March 31, 2009 belt, chain, bungie cord, spaghetti noodle... it's one of those darn things. :doh: Link to comment Share on other sites More sharing options...
BBCchris Posted March 31, 2009 Author Share Posted March 31, 2009 Here are some pics...... just your run of the mill 89 MJ ;) Link to comment Share on other sites More sharing options...
BLHTAZ Posted March 31, 2009 Share Posted March 31, 2009 Timing belt? Timing "belt"? In an MJ? The 2.5L uses the same silent roller timing "chain" that the 4.0L does. Yep...with the exception being that the 2.5L uses a tensioner and the 4.0L does not. The tensioner can go bad and cause similar issues. Link to comment Share on other sites More sharing options...
BBCchris Posted April 1, 2009 Author Share Posted April 1, 2009 Well there is no need to try and figure it out...... She passed away in the garage last night :shake: RIP. It was it's way of saying that it wants the 4.0 and the 4x4 stuff. I'll start breaking it down tonight..... because that's what it would of wanted. ;) Link to comment Share on other sites More sharing options...
project88mj Posted April 1, 2009 Share Posted April 1, 2009 good idea Link to comment Share on other sites More sharing options...
streetjeep2.5 Posted April 1, 2009 Share Posted April 1, 2009 the reason you have no power is ........its a 2.5 do the 4.0 swap asap My 87 SWB 4x2 2.5 TBI 4 speed w/no power anything except brakes and no ac and was rebuilt with a very mild cam and Clifford header and single in dual out Flowmaster and high flow converter scoots along pretty good for a 4 popper. The cam and header and exhaust helped by at least 15hp, I think. 'Course, no power anything helps! ;) Link to comment Share on other sites More sharing options...
BBCchris Posted April 1, 2009 Author Share Posted April 1, 2009 It's all good, it was going to get the 'swap' and repaint anyway.... it's just going to happen quicker than I had planned. Now I just gotta figure out what color before I stab the 4.0 in. And if anyone was curious to what I found last night..... it seems to of popped its headgasket sometime in the past and once it gets hot the coolant starts coming out the exhaust, that seems to be the reason why the cat was cut off. The timing chain is worn and pretty loose, the oil pressure after warm up is less than 5psi and it has a pretty audible knock at idle. Funny thing is I have a '01 XJ next to the garage with the same condition. I'll snap some pictures of the 'progress' as soon as I start breaking her down. -Chris -I don't have a problem with the 4cyl and if I had one sitting in the garage I might toss it back in but in the 25 or so XJ's I've rebuilt and or owned in the past 15 years...... well you just gotta go with what you know. :thumbsup: Link to comment Share on other sites More sharing options...
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