raviolli Posted January 6, 2012 Share Posted January 6, 2012 my brake booster and master cylinder came in today so i made a trip to the auto parts store for some fluid, cleaner, booster vacuum hose, etc. and figured id get some plugs and wires while I'm at it since its been missing the past couple days. i changed all the plugs and wires, went to start it up and it was still going rough. then i noticed i was looking at the diagram for the wrong model year. (had the diagram out because i couldnt see the number on the cap and i don't do my wires one by one. why? beats me :nuts: ) so i got the wires correct and went to fire up, and got nothing but backfires up through the throttle body :hmm: :dunno: double, triple, quadruple, and quintuple checked the wires and firing order, etc. :help: :help: :help: :help: :help: :help: :help: :help: Link to comment Share on other sites More sharing options...
Eagle Posted January 6, 2012 Share Posted January 6, 2012 You may have the sequence correct, but are you sure you have the #1 wire on the #1 terminal of the distributor cap? Link to comment Share on other sites More sharing options...
Jeep Driver Posted January 6, 2012 Share Posted January 6, 2012 Double check your rotor cap or 'button' position. Could start from scratch and do the TDC method.........something must be off. Link to comment Share on other sites More sharing options...
raviolli Posted January 6, 2012 Author Share Posted January 6, 2012 yeah after noticing i was looking at the wrong diagram, i also noticed that there actually ARE numbers on the cap. well, one number anyways. #1 is marked (raised, not printed) Link to comment Share on other sites More sharing options...
raviolli Posted January 6, 2012 Author Share Posted January 6, 2012 took the rotor out when the cap was off....put it back in. don't really know what else to check lol thanks for the responses so far, but still stuck here. i think I'm gonna go get a new cap and rotor. can't hurt Link to comment Share on other sites More sharing options...
JeffN Posted January 6, 2012 Share Posted January 6, 2012 Distributor is probably not set to number one cylinder and the last person probably put them on where it worked, set it on top dead center and see where the rotor button points. It should point to the number one cylinder. Link to comment Share on other sites More sharing options...
raviolli Posted January 7, 2012 Author Share Posted January 7, 2012 how do i get a motor to TDC if the engine is in the truck? ive never done it also, i put in a new cap and rotor and now its backfiring just like before, only with the smell of firecrackers under the hood :shake: Link to comment Share on other sites More sharing options...
Jeep Driver Posted January 7, 2012 Share Posted January 7, 2012 http://tomasz.korwel.net/2006/12/19/rep ... l-engines/ This is for the 4.0 but the principles are the same for the 2.5 Link to comment Share on other sites More sharing options...
raviolli Posted January 7, 2012 Author Share Posted January 7, 2012 well i guess ill have to give that a try. its my only option at the moment but ill do it another day. Tonight ill skip to the end and "take a beer" :cheers: i guess i should get a new distributor too? also, thought this was funny, but at the same time, made this whole thing an even bigger headache. the manual shows a diagram...it says firing order: 4-3-2-1 also says: distributor rotation: clockwise looking at the diagram, starting with #1, going around clockwise, order goes 1-2-3-4 the book contradicts itself :fs1: :roll: :no: :mad: :redX: :nuts: :???: :shake: :huh???: :dunno: :doh: :wall: :fs2: :hmm: :thwak: Link to comment Share on other sites More sharing options...
MJCARENA Posted January 7, 2012 Share Posted January 7, 2012 I thought it was 1,3,4,2 clockwise. Link to comment Share on other sites More sharing options...
raviolli Posted January 7, 2012 Author Share Posted January 7, 2012 i thought so too...but i was looking at the wrong year. according to my manual (and we all know how accurate those are :roll: ) 1984-1988 2.5's had a 4-3-2-1 firing order and 1989-1996 2.5's had the 1-3-4-2 firing order Link to comment Share on other sites More sharing options...
airspeed Posted January 7, 2012 Share Posted January 7, 2012 If your distributor is in properly #1 will be at ~5 o'clock. The distributor turns clockwise as viewed, and you can see the firing order from this photo. Link to comment Share on other sites More sharing options...
raviolli Posted January 7, 2012 Author Share Posted January 7, 2012 tried that way and a few other ways last night. just kept getting backfires. this morning though i went to take my dog out and decided to give it another shot with the 1-3-4-2 so i popped the hood, plugged em in and she started up. still runs really rough though and backfires through the exhaust. i just don't get why the manual's gonna tell you 4-3-2-1 and then show 1-2-3-4 in the picture :huh???: Link to comment Share on other sites More sharing options...
Geonovast Posted January 7, 2012 Share Posted January 7, 2012 The 2.5 NEVER had a 4-3-2-1 firing order. I do not know of ANY 4 cylinder that has the firing order. The internals of the engine make that firing order impossible. The 2.5's firing order is 1-3-4-2, regardless of year. It should even be cast into the manifold itself, so you can check when installing wires. Link to comment Share on other sites More sharing options...
airspeed Posted January 8, 2012 Share Posted January 8, 2012 The only other thing I can think of you have a burnt and or sticking exhaust valve? You will need to do a leak down or compression check. Link to comment Share on other sites More sharing options...
raviolli Posted January 8, 2012 Author Share Posted January 8, 2012 i always thought it was 1-3-4-2 ...thats why i was stumped when the book said otherwise. completely forgot it was stamped on the manifold lol airspeed: my original thought was a valve staying open when it shouldnt. its not backfiring anymore...just running extremely rough. i think running on only 3. hard to say, i don't want it running in this condition so i havent really listened to it. everyone ive talked to says check the timing but it came on so suddenly and i don't drive this truck. i doubt the timing would just throw itself off like that. and not to mention i seafoamed it right before it started running rough. probably got a bunch of gunk stuck on the valves in the process of burning everything out of it...thats my guess Link to comment Share on other sites More sharing options...
raviolli Posted January 9, 2012 Author Share Posted January 9, 2012 i just want EVERYONE to see this its blurry, yes, but if you look closely, you can see I am not crazy :hmm: :shake: :no: Link to comment Share on other sites More sharing options...
MJCARENA Posted January 9, 2012 Share Posted January 9, 2012 What manual is that? I have a Haynes and a Chilton and they are both correct. You must have a Chinese knock off, where some little kid got paid a quarter to copy the manual. Link to comment Share on other sites More sharing options...
airspeed Posted January 9, 2012 Share Posted January 9, 2012 Check for a burnt and or sticking exhaust valve. A leak-down or compression check is needed. Something else to look at would be a REAL loose or skipped timing chain... Link to comment Share on other sites More sharing options...
Geonovast Posted January 9, 2012 Share Posted January 9, 2012 Actually, it could be timing related. The 2.5 uses a tensioner on the timing chain, and that could have failed, causing an sudden timing problem. Link to comment Share on other sites More sharing options...
raviolli Posted January 9, 2012 Author Share Posted January 9, 2012 it is a Chilton's manual. Here's a clearer pic taken from my dads phone rather than my own even the 2.8L showed a firing order of 1-2-3-4-5-6 :nuts: the only picture that seemed right was the 5.2l and even then i wouldnt trust this book. i suppose i should burn it :popcorn: I'm going to check the timing...probably on wednesday since i work both of my jobs both tomorrow and tuesday. if that doesnt help, it seems ill be pulling the head :headpop: it just sucks that i finally rounded up my brake parts and am just about ready for some tags....then this happens. plus i hate to do this kind of work when I'm planning a swap in the future. BUT! -- thats the beauty of the jeep curse i guess Link to comment Share on other sites More sharing options...
airspeed Posted January 9, 2012 Share Posted January 9, 2012 You should do a leak down test before you pull the head... Note: Pulling the head on a 2.5 is not a difficult task, you can R&R a head in four hours. Link to comment Share on other sites More sharing options...
raviolli Posted January 9, 2012 Author Share Posted January 9, 2012 a leak down test will tell me where the leak is (if there is one) is there any point in doing a compression test if i do a leak test? or will the compression test just tell me what i already know from the leak down? Link to comment Share on other sites More sharing options...
airspeed Posted January 9, 2012 Share Posted January 9, 2012 The leak down test is more difficult to do, but is a more precise diagnostic tool. You can skip the compression test and just do the leak down, it will tell you clearly where the problem is. Link to comment Share on other sites More sharing options...
raviolli Posted January 9, 2012 Author Share Posted January 9, 2012 okay, thats what i thought oh and i know pulling the head isnt difficult, I'm just afraid of what i might find. this truck has 276,500mi. on it and ive probably only put about 50 of em on...and have no info on its history Link to comment Share on other sites More sharing options...
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