dancome433 Posted February 22, 2009 Share Posted February 22, 2009 So my comanche has been sitting in my garage since december, getting a new clutch put in. finally after procrastinating long enough, i finshed it last week. I bolted everything back together and plugged all the connectors in. But now it doesnt start, i can turn it and everything it just doesnt run. So my buddy and i checked into and found out its not getting any spark. Thinking it was the coil i replaced it, and guess what no spark. Any ideas? Link to comment Share on other sites More sharing options...
Eagle Posted February 22, 2009 Share Posted February 22, 2009 If you did the clutch, you had the bellhousing off. The CPS (Crankshaft Position Sensor) is on/in the bellhousing. Did you reinstall it correctly? The bolts have a shoulder to locate the sensor accurately. If you lost those and use full-threaded bolts, the CPS may not be positioned right. Also, if you left the CPS on the bellhousing, it's possible it got dameged from handling. The vast majority of no-starts with the XJ and MJ eventually come down to the CPS. Does the fuel pump run for a few seconds when you first turn on the key? Have you verified fuel pressure at the injector rail? Link to comment Share on other sites More sharing options...
BLHTAZ Posted February 22, 2009 Share Posted February 22, 2009 If you did the clutch, you had the bellhousing off. The CPS (Crankshaft Position Sensor) is on/in the bellhousing. Did you reinstall it correctly? The bolts have a shoulder to locate the sensor accurately. If you lost those and use full-threaded bolts, the CPS may not be positioned right. Also, if you left the CPS on the bellhousing, it's possible it got dameged from handling. The vast majority of no-starts with the XJ and MJ eventually come down to the CPS. Does the fuel pump run for a few seconds when you first turn on the key? Have you verified fuel pressure at the injector rail? :agree: CPS is definitely on the top of the list here... Link to comment Share on other sites More sharing options...
dancome433 Posted February 22, 2009 Author Share Posted February 22, 2009 If you did the clutch, you had the bellhousing off. The CPS (Crankshaft Position Sensor) is on/in the bellhousing. Did you reinstall it correctly? The bolts have a shoulder to locate the sensor accurately. If you lost those and use full-threaded bolts, the CPS may not be positioned right. Also, if you left the CPS on the bellhousing, it's possible it got dameged from handling. The vast majority of no-starts with the XJ and MJ eventually come down to the CPS. Does the fuel pump run for a few seconds when you first turn on the key? Have you verified fuel pressure at the injector rail? thanks yea the fuel pump does run for a couple of seconds when i turn the key, and yea i do have fuel going through the fuel injector rail, ill check the CPS real quick, this might sound stupid but just so i know what I'm looking for anybody have any pics of the CPS Link to comment Share on other sites More sharing options...
BLHTAZ Posted February 22, 2009 Share Posted February 22, 2009 I don't have a pic of it handy right now, but it is about the 11:00 position on the bellhousing and, as Eagle said, has two bolts that hold it in place. Please don't take this wrong...it's just an observation and not meant as anything but that. :thumbsup: It's kind of scary, and may tell a story alone, that you have to ask for pics of it when you just had the tranny out and should be easily familiar with what it is and where it is as you would have to deal with it when removing and installing the tranny ;) . Link to comment Share on other sites More sharing options...
djag12 Posted February 22, 2009 Share Posted February 22, 2009 I had a new clutch put in and a week later the CPS went. Don't know if it was just it's time or if it was damaged with new clutch instal. Link to comment Share on other sites More sharing options...
dancome433 Posted February 22, 2009 Author Share Posted February 22, 2009 I don't have a pic of it handy right now, but it is about the 11:00 position on the bellhousing and, as Eagle said, has two bolts that hold it in place. Please don't take this wrong...it's just an observation and not meant as anything but that. :thumbsup: It's kind of scary, and may tell a story alone, that you have to ask for pics of it when you just had the tranny out and should be easily familiar with what it is and where it is as you would have to deal with it when removing and installing the tranny ;) . no worries i found a pic of it and found it, and it is connnected, but I'm thinking to lower the tranny back down to make sure its in properly positioned right. and i had friends come over and help me out, and one of my friends was the one who took the tranny down while i did other things, and he wasnt with me when i put the tranny back, so i put everything back to my knowledge, and having my friend talk me through a couple of things(sounds scary but i had another friend who was there to help me out) Link to comment Share on other sites More sharing options...
dancome433 Posted February 22, 2009 Author Share Posted February 22, 2009 I had a new clutch put in and a week later the CPS went. Don't know if it was just it's time or if it was damaged with new clutch instal. if you don't mind me asking how much did a new CPS cost you, i might just replace it Link to comment Share on other sites More sharing options...
Eagle Posted February 23, 2009 Share Posted February 23, 2009 no worries i found a pic of it and found it, and it is connnected, but I'm thinking to lower the tranny back down to make sure its in properly positioned right. and i had friends come over and help me out, and one of my friends was the one who took the tranny down while i did other things, and he wasnt with me when i put the tranny back, so i put everything back to my knowledge, and having my friend talk me through a couple of things(sounds scary but i had another friend who was there to help me out) Slow down, Matey. You don't have to drop the transmission to position the CPS -- unless you didn't put the bellhousing back on properly. There should have been two hollow locating sleeves, on on each side of the block, that the bellhousing fitted onto for location, and then the lower bolts go through those hollow sleeves. You DID have the two sleeves in the block, I hope. Did you remove the CPS before you removed the tranny and bellhousing? If not (and I'm going to guess that you didn't), how much banging around did you do getting the tranny out, and then getting it back in place? My guess is that the CPS took a hit and is physically damaged. Also -- are you using the original flywheel? If not, did you buy a flywheel? If you got a flywheel from the wrong year, it may not work with the CPS for your vehicle. Link to comment Share on other sites More sharing options...
dancome433 Posted February 23, 2009 Author Share Posted February 23, 2009 Slow down, Matey. You don't have to drop the transmission to position the CPS -- unless you didn't put the bellhousing back on properly. There should have been two hollow locating sleeves, on on each side of the block, that the bellhousing fitted onto for location, and then the lower bolts go through those hollow sleeves. You DID have the two sleeves in the block, I hope. Did you remove the CPS before you removed the tranny and bellhousing? If not (and I'm going to guess that you didn't), how much banging around did you do getting the tranny out, and then getting it back in place? My guess is that the CPS took a hit and is physically damaged. Also -- are you using the original flywheel? If not, did you buy a flywheel? If you got a flywheel from the wrong year, it may not work with the CPS for your vehicle. Ok, the reason i was going to lower the tranny was so i had better access to it, i wasnt going to unbolt it from the block, but ill try to work with it without lowering it. When i put the tranny back in i did put the bell housing back properly. Yes i do have the sleeves on the block, and i did remove the CPS from the bell housing completely because i pulled the tranny completely out from underneath the truck and i remember bolting it back to the block. When i pulled it I didnt do any banging, just prying and pulling. and i did use the orginal flywheel. so just to be on the safe side since these are known to go out whenever they feel like i think I'm just going to replace the CPS. Link to comment Share on other sites More sharing options...
Pete M Posted February 23, 2009 Share Posted February 23, 2009 Just a photo for anyone reading this that doesn't know where it is. :D Link to comment Share on other sites More sharing options...
500 MJ Posted February 23, 2009 Share Posted February 23, 2009 I love CPS - actually no - they cause problems so I don't think I love them too much. I'm having problems with mine too - dang things. :wall: If you get a new one - I would suggest you go through a dealer or a high quality parts source. These sensors are such a vital part in the way our Jeeps are setup that buying a "made in China" version might not be what you want to do... Best of luck! Link to comment Share on other sites More sharing options...
Eagle Posted February 23, 2009 Share Posted February 23, 2009 I hate the things. Truth be known, I'd rather have a conventional distributor with points and a condensor that you replace every 10,000 miles. The parts are cheap, and it's easy to do a points job. My issue with the CPS is that a Jeep is supposed to be a "go anywhere" vehicle. I just don't like the idea of a safari vehicle that you may have out in the boonies, miles and miles from anything remotely resembling civilization or a paved road, and the CPS may decide to die on you out there. Most Jeep owners won't even know what a CPS is, and if they do they probably don't carry a spare. Ever try to swap a CPS in a swamp? (No, I haven't, either. But I have swapped on in a snow-packed driveway on a 25-degree day.) I don't really care for fuel injection for the same reason. If it fails when you're beyond "out there," you're stuck. I've driven an old pickup with a carburetor by hanging a coffee can half filled with gasoline from a strut under the hood and running a drip tube to the carburetor float bowl inlet. Try that with EFI. Link to comment Share on other sites More sharing options...
dancome433 Posted February 23, 2009 Author Share Posted February 23, 2009 yea i didnt know what it was till today and i already hate, why jeep decided to put those damn things in beats me, thanks pete for the pic, it helped me a little bit more, and i think now after seeing that i think i did break it, time to go spend some more money, is Oriellys a good source for these things Link to comment Share on other sites More sharing options...
500 MJ Posted February 23, 2009 Share Posted February 23, 2009 I'm gonna buy mine from the dealership or maybe Crown Automotive. Got a quote a few weeks back from bhlTaz that they were ~$45 at the dealership... not too bad in my opinion for the sense of security you get with a "good part" Link to comment Share on other sites More sharing options...
Eagle Posted February 23, 2009 Share Posted February 23, 2009 yea i didnt know what it was till today and i already hate, why jeep decided to put those damn things in beats me, ALL modern vehicles use them. Jeep was not the first. They are a nuisance to change, but they usually last about 100,000 miles (give or take 75,000 :D ), so easy access wasn't at the top of the list of priorities when designing where to put it. Link to comment Share on other sites More sharing options...
terrawombat Posted February 23, 2009 Share Posted February 23, 2009 yea i didnt know what it was till today and i already hate, why jeep decided to put those damn things in beats me, ALL modern vehicles use them. Jeep was not the first. They are a nuisance to change, but they usually last about 100,000 miles (give or take 75,000 :D ), so easy access wasn't at the top of the list of priorities when designing where to put it. If not a crank sensor, then a cam sensor - does the same thing, but at half the speed ;) A lot of modern cars put the crank position (or crank angle) sensors on the front of the engine, but a lot of modern engines are overhead cam designs and access to the timing components is meant to be easy. I guess we should be lucky that Jeep didn't put the CPS in the 12 o'clock position! Link to comment Share on other sites More sharing options...
dancome433 Posted February 24, 2009 Author Share Posted February 24, 2009 ALL modern vehicles use them. Jeep was not the first. They are a nuisance to change, but they usually last about 100,000 miles (give or take 75,000 :D ), so easy access wasn't at the top of the list of priorities when designing where to put it. well that makes more sense now since my comanche has 93000 miles, and its probably never been changed Link to comment Share on other sites More sharing options...
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