Shandley Posted November 24, 2009 Share Posted November 24, 2009 Greetings. I have a 1990 Comanche with a 2.5L engine and a 5 speed manual tranny. It is VERY hard to start. When it does start, it runs rough and I have to feather the gas to keep it going. When it warms up, it's drivable but if I give it just a little with the accelerator, it bogs and hesitates. This is driving me nuts. Here is what I have done and checked so far: I changed the fuel filter Replaced the fuel pump Tested fuel pressure (a-ok) Tested the MAP sensor (a-ok) checked distributor for proper placement and position. Changed distributor cap and rotor Changed Spark plug wires Changed ignition coil Had the injector cleaned Tested compression (100%) Changed air filter ... I'm sure I am missing a lot here but any help would be good help Much thanks! Link to comment Share on other sites More sharing options...
dasbulliwagen Posted November 24, 2009 Share Posted November 24, 2009 Crank position sensor on the bellhousing, Oxygen sensor, clogged/blocked cat convertor or muffler....uuuhhhhhhhhhhh, water in the gas tank, bad fuel, ignition coil not giving good enough spark, bad engine ground.... stuff like that. Check it all! Good luck, let us know what you find!, welcome to the club! Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 24, 2009 Share Posted November 24, 2009 Welcome to the mysterious Renix world. All the above suggestions could cause these symptoms since you have validated your fuel pressure at the rail, si? Link to comment Share on other sites More sharing options...
garyindiane Posted November 24, 2009 Share Posted November 24, 2009 My bad EGR made mine act like that. Check this out: http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm -Gary Edit: Sorry link is for renix 4.0. Did'nt see you had a 2.5. Link to comment Share on other sites More sharing options...
Shandley Posted November 25, 2009 Author Share Posted November 25, 2009 Thanks to all... but nothing yet. I feel my next step is try to retrieve codes from my ECM. I have found a connector over the passenger side wheel well under the hood. It has 2 yellow caps covering the connector pins. I have the picture they show in the Haynes manual and a photo of the caps. It shows to jumper a couple pins and turn the ignition to ON. I did that but I see no Check Engine light. Nothing Flashes The Key ON-Off-ON-Off-On thing doesn't work (it did in my previous Chrysler type vehicles). Furthermore, I cannot find a Check Engine Light at all on my dash. Being a 1990, there is NO OBD-II connector. Is the 1990 the only Jeep without a way to manually retrieve codes?? Also, where would my check engine light be?? Maybe the bulb is burnt out. lol This is the photo of the Yellow covers covering the following photo. This is what is under those yellow covers. Please note that it mentions a diagnostic method for the V6 engine but not for my 2.5L 4cyl. Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 25, 2009 Share Posted November 25, 2009 Thanks to all... but nothing yet. I feel my next step is try to retrieve codes from my ECM. The Key ON-Off-ON-Off-On thing doesn't work (it did in my previous Chrysler type vehicles). Furthermore, I cannot find a Check Engine Light at all on my dash. Being a 1990, there is NO OBD-II connector. Is the 1990 the only Jeep without a way to manually retrieve codes?? Also, where would my check engine light be?? Maybe the bulb is burnt out. lol Unfortunately you can not check fault codes w. the key trick until the 91 OBDI models arrived. Strangely enough you can with the 1984 to 1986 V6 models though. If you know someone w. a DRB-II scanner (dealer), that is the only way I know of to do it. The CHECK ENGINE light is in your cluster on the left indicator panel side. If should illuminate when you turn the key on before starting so you can check the bulb. See if you can "borrow" a computer from a similar MJ to stick in it temporarily to see if it cures the problem. Seems like you have done about everything else. Link to comment Share on other sites More sharing options...
Shandley Posted November 25, 2009 Author Share Posted November 25, 2009 Well, thank you for the info. I now have a sad heart. No one I know has a DRB-II scanner. I have never seen another 1990 Jeep Comanche with a 2.5L around, let alone one with a computer I can use. Well, I can't wait to see the burnt out Check Engine bulb. I suppose that means it's been on for a while, eh? Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 25, 2009 Share Posted November 25, 2009 Maybe if you talked nicely to Buffalo Bob (the esteemed Wildman of the North), he might "lend" you one for testing purposes. :D Link to comment Share on other sites More sharing options...
Shandley Posted November 25, 2009 Author Share Posted November 25, 2009 Thank you. I sent him a pleading message. I can only hope. I did notice something new when I was trying to start the truck. The power cut out every 3 or 4 seconds of cranking. The battery is pretty fresh and has a fresh charge on it. I don't know what it could be. Any ideas? Could this be relative to my other problems? Link to comment Share on other sites More sharing options...
Pete M Posted November 25, 2009 Share Posted November 25, 2009 checked the CPS, IAC and TPS yet? Link to comment Share on other sites More sharing options...
freakjeep93 Posted November 25, 2009 Share Posted November 25, 2009 definatly related to your probs. in my mind anyway (don't trust everything i sasy I'm not a expert machanic ) but it sounds like you may have a bad coin or ground or it may just be a bad connectio....? oh and WELCOME TO THE CLUB!! Link to comment Share on other sites More sharing options...
Shandley Posted November 25, 2009 Author Share Posted November 25, 2009 checked the CPS, IAC and TPS yet? Where is the IAC located? The CPS checks out and I will double check the TPS, just to make sure I did it right. Link to comment Share on other sites More sharing options...
Pete M Posted November 25, 2009 Share Posted November 25, 2009 IAC is right next to the TPS. Did you pull the CPS? sometimes it can get gunked up with rust attracted to the magnet. Link to comment Share on other sites More sharing options...
cruiser54 Posted November 26, 2009 Share Posted November 26, 2009 What kind of shape is that bundle of vacuum hoses in near the throttle body? A very common source of vacuum leaks BTW. A poor vacuum line to the MAP sensor on the firewall can also cause running problems. Another thing to do no matter what, is to remove the ground cable from the driver side firewall and scrape the paint off the firewall, clean the eyelet and reconnect. Also check the other end of that strap whrer it attaches to the head. This was a grounding issue when the cars were new. I'm sure those connections have only deteriorated since then.............. Link to comment Share on other sites More sharing options...
Shandley Posted November 26, 2009 Author Share Posted November 26, 2009 What kind of shape is that bundle of vacuum hoses in near the throttle body? A very common source of vacuum leaks BTW. A poor vacuum line to the MAP sensor on the firewall can also cause running problems. Another thing to do no matter what, is to remove the ground cable from the driver side firewall and scrape the paint off the firewall, clean the eyelet and reconnect. Also check the other end of that strap whrer it attaches to the head. This was a grounding issue when the cars were new. I'm sure those connections have only deteriorated since then.............. The hoses are in fantastic shape (I just replaced any that were even close to suspect). I also made damn sure I put them in the right place. I will be scraping the paint off of the ground cable and checking the other end. Thanks! Say, does anyone know where the ECU is on this thing?? Link to comment Share on other sites More sharing options...
cruiser54 Posted November 26, 2009 Share Posted November 26, 2009 I'm not sure on the 2.5 but on the 4.0 there is a bundle of grounds at the dipstick tube mounting bracket that could be cleaned and tightened also.Let me know please. Link to comment Share on other sites More sharing options...
Wildman Posted November 26, 2009 Share Posted November 26, 2009 Maybe if you talked nicely to Buffalo Bob (the esteemed Wildman of the North), he might "lend" you one for testing purposes. :D Thank you. I sent him a pleading message. I can only hope. I did notice something new when I was trying to start the truck. The power cut out every 3 or 4 seconds of cranking. The battery is pretty fresh and has a fresh charge on it. I don't know what it could be. Any ideas? Could this be relative to my other problems? Yes, I received and responded to the PM :D :hmm: Me think Mr. Hornbrod knows that I just drag home a '88, 2.5, 5 speed a couple weeks ago (only my 2nd 2.5) And this one just happens to be for parts :roll: Yea, the day job is slowing up, so......I have time to get some parts together, and I could send you a ECU from the '88 for you to try out. But, I don't think that's your problem. So, you say it's cutting out (the starter stops) after 3-4 seconds of cranking..........Bad battery cables!!! Take the plastic loom off the cables and check them, if you see any corrosion, replace them, there a $20 item for both cables. I've read all the other items you changed, and no mention of the cables, or did I miss that one :hmm: As noted above, check the grounds, replace the body to engine ground strap, if you see any green color at all. The Renix is set up to run on the +ground system, in other words, all the switches, relays and such have power to them, and the contacts are open or closed thru the negative ground system, so........Grounds are very important. Also, once you find your ECU (seen the other post) make sure the mounting plate is grounded, if in doubt, add an additional ground from the plate, to the engine stud, where the battery ground is connected (that's also where the original ground wire is located) The PM I responded to, I also mentioned that the 2.5 is notorious for the timing chain to slip, because of a plastic guide at the chain, wears out, and can cause the timing to be off, which kind of sounds like your original problem :hmm: Post up the mileage on this MJ. I'll let you respond to all this before we go on ;) Link to comment Share on other sites More sharing options...
Oizarod115 Posted November 26, 2009 Share Posted November 26, 2009 Well, thank you for the info. I now have a sad heart. No one I know has a DRB-II scanner. I have never seen another 1990 Jeep Comanche with a 2.5L around, let alone one with a computer I can use. Well, I can't wait to see the burnt out Check Engine bulb. I suppose that means it's been on for a while, eh? argh come on hornbrod! everybody knows renix jeeps don't have check engine lights :clapping: seriously, your jeep shouldn't have one. its there in the cluster to the left but it will never light up. it does not store codes or even make codes, you can hook up a scanner to it and get information about sensors and such but it has no code software Link to comment Share on other sites More sharing options...
Shandley Posted November 26, 2009 Author Share Posted November 26, 2009 argh come on hornbrod! everybody knows renix jeeps don't have check engine lights :clapping: seriously, your jeep shouldn't have one. its there in the cluster to the left but it will never light up. it does not store codes or even make codes, you can hook up a scanner to it and get information about sensors and such but it has no code software Oh man... I spent 3 hours in my truck pulling the bezels out and trying to swap bulbs. I was about to post a picture of the shine through. lol.. I guess there is no need now... unless someone wants to see. All ground points are now clean. All ground straps are as they should be but to make sure, I pulled them, cleaned and scraped them, and put them back together. I like the idea of it being a timing issue as it's one of the only things I haven't tried. Link to comment Share on other sites More sharing options...
HOrnbrod Posted November 26, 2009 Share Posted November 26, 2009 argh come on hornbrod! everybody knows renix jeeps don't have check engine lights :clapping: seriously, your jeep shouldn't have one. its there in the cluster to the left but it will never light up. it does not store codes or even make codes, you can hook up a scanner to it and get information about sensors and such but it has no code software Obviously you no nothing about OBDI. I'm not going to even comment - figure it out for yourself. :roll: Link to comment Share on other sites More sharing options...
aerocorey Posted November 26, 2009 Share Posted November 26, 2009 Ummm, not to get in the middle here, but Renix isn't OBD-anything. I don't know much about OBD-I or OBD-II, but Renix is neither, doesn't store codes, and doesn't have a CEL/MIL. Link to comment Share on other sites More sharing options...
Shandley Posted November 26, 2009 Author Share Posted November 26, 2009 For anyone who is interested, and since I ripped apart my dash to get it, here is what the left cluster has for a shine though skin: I don't see a check engine light, but it's probably the top left or something else that I just don't know. I put little white light symbols beside the ones that have lights in my vehicle ( 2WD ) Link to comment Share on other sites More sharing options...
Wildman Posted November 26, 2009 Share Posted November 26, 2009 Renix is Renix. aerocorey is correct, the ECU don't store any codes, every start is a fresh start, and the ECU uses the input feed from the sensors to make the adjustments for fuel, ignition timing, what not. There is no "CEL" on the Renix. Shandley..........Don't run off, I'm doing your PM reply, for the 2nd time (hit the wrong button :fs1: ) What your showing is the "typical" dash insert, most of the "items" are not used in the MJ. And the ones you high lighted are correct for a manual, but that red triangle I've never see :hmm: Link to comment Share on other sites More sharing options...
Shandley Posted November 26, 2009 Author Share Posted November 26, 2009 Thanks Wildman. The red triangle is a hazard lights symbol. Did I mention this vehicle is Canadian? Link to comment Share on other sites More sharing options...
Wildman Posted November 26, 2009 Share Posted November 26, 2009 No, you didn't. :doh: Lets see........does that mean the steering wheel is on the right side????? Oh, that's something else, never mind. OK, for the folk's following........he had a backfire!!!! That's a good sign :banana: Fuel & spark. Just not in the right order. So, he's going to re-set the distributor and see what that does. Link to comment Share on other sites More sharing options...
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