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  1. #21
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Quote Originally Posted by JPNinPA View Post
    Rockauto.com for your parts. They highlight what parts are OEM and also highlight parts that performed the best.


    Sent from my iPhone using Jeepz.com mobile app
    Thanks Everyone! So I tested the ASD socket and we have a light! Also tested the grey wire to the coil, it did not flash. Another twist was that the engine temp sensor (I think) was unplugged. I did plug it back although the connections were pretty filthy and still no start. Are we looking at a new ignition coil or something worse? Thanks again!

  2. #22
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    coil would be my thought.

  3. #23
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    I think I would replace that crank sensor in the trans first. since its cheap and normally has been the no-start cause for my 4.0s
    no more jeeps at this time. next time it will be a cj with a v8

  4. #24
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    that is just me though
    no more jeeps at this time. next time it will be a cj with a v8

  5. #25
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Reading back in earlier posts , alternator replacement was posted .
    althoigh that may have no bearing on this no start , there is diagnostic checks which will involve checking the field on the back of the alternator . There is a wire which connects to a terminal on the field and also splices to the ignition coil negative harness . The coil connector is two wire .
    the positive side splices to a wire that connects to the alt. field . Terminal C according to a wiring diagram for a '92 YJ. I'm hoping the diagram will be correct for your '95 . It shouldn't be for off if not the same . The negative wire , yellow w/black tracer ( stripe ) feeds back to the PCM , terminal 19. The positive is dark green w/black tracer .
    With the ignition on , and a COMPUTER SAFE test light , probe the positive wire for current .
    the PCM should complete the ground . With the computer safe test light . Checking power is with its alligator clip to battery negative . Checking ground is with the alligator clip on battery positive . It is important to do this right . The diode ( not light bulb ) on the test light will light RED upon checking power and light GREEN when checking ground.
    It would be nice right about now to have a NOID light to check if one or more injector harness connector shows power . The computer safe test light can be used too but each ( there are two) wore must be checked separate . One wire is power which is live with ignition on and the other is a computer feedback wire which supplies ground to complete the circuit.
    as you can see , it's just easier to have a NOID light . These noid lights plug into each injector harness plug separately . Only one is needed and can be moved to each injector harness connector if need be. I mention the injector harness because not only is it your interest to determine if the injectors are firing when cranking but the dark green / black wire from the alternator field which also goes to the ASD and feeds back to the PCM terminal 57 as a sense wire . As you can see , this is a little involved and hopefully not intimidating.
    To recap , please obtain a computer safe test light and a NOID light . Not expensive and np Rey good to have for these occasions . Christmas is coming and I'd like to see you take that ride .
    Checking injector harness and ignition coil harness should be done as soon as the key is turned on and cranking occurs , one at a time of course . Recycling the key to off to reset.
    The reason is because of the oil pressure descent register for a running engine , the PCM via the ASD will terminate injector ground to stop injector pulse to prevent flooding which is also part of safety in the event of roll over. The ignition should fire regardless , to my knowledge .
    I know that earlier posts read that power was found TO the ignition coil but we need to confirm all the above before we do something like condemn a PCM . I really don't think the PCM is faulty but we have to step by step confirm what part of a normal start we have or don't .
    It is entirely possible that the CKP ( crankshaft position sensor ) located on the bell housing of the trans on the driver's side may be the culprit . Thankfully you've got a YJ and not a Cherokee . The wrangler's CKP is easier to access. As I've said in an earlier post , only a labscope or good scan tool can verify if the CKP or any sensor is operating within its normal range but I realize we don't have that luxury . Too bad a wrecking yard isn't nearby for you , I would say to visit and try your luck with one ( if found ) from a jeep there . Although this is a common glitch and many a CKP has been changed , I put more trust and faith in the OEM sensors than chain store parts . If you were lucky to,score one and it tested better results than the one on your Jeeper now , it would be worth a shot. I've found parts in junkyards many a time that worked fine . Just knowing my '92 with many of its original parts still doing its thing is encouragement enough to try . Hope this helps .
    Last edited by greg92jeepxj; 12-13-2016 at 05:02 PM. Reason: Adittion
    Never overlook the obvious . It's usually right in front of us

  6. #26
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Thank you again greg92jeepxj, superj, 69jeepcj, et al.!
    I had a dang meeting after work last night so I didn’t getthe chance to try these suggestions… but my plan is to do some more troubleshooting tonight.
    I have a corded light probe, but not sure if its computersafe. I’m assuming it’s an el cheapofrom harbor freight, I’ll check and if not I can pick one up.I do have a digital multimeter that I’mlearning to use as well.I’ve never used a NOID light but willing tolearn and give that a try as well so I will go pick one up today.I’ll continue to search for an OEM CKPsensor.I watched a video on CKP andattempted to test it.It seemed fine,but that was only voltage wise.Perhapsthere may be an underlying issue there.Would it be worth grabbing an aftermarket CKP as a last resort?
    My focus has been mainly on the relay sockets and the ignitioncoil recently. I did pick up a coil at NAPA in case I needit, so we shall see.Do you think it would be necessary or worthchanging that out at this point?It doesnot appear to be a difficult swap.
    Additionally, I noticed the temperature gauge sensor (near the back of the engine) wasdisconnected (likely no bearing on this issue) so I hooked it back up andactually purchased a replacement as there does not seem to be a goodconnection.I remember several monthsago when I changed the valve cover gasket this was loose and would occasionallycome undone, but she ran fine and only thing I noticed was that my temp gaugewas not working.
    Your recommendation in regards to checking the wires aroundthe alternator is one I have not tried or looked at before. That’s a good call as well!I’ll give that a check too!
    What I thought might be an unrelated (which now I'm thinkingcould be an underlying issue) that I planned/intend on fixing LATER was withthe heater fuse. I didn't intend on steering the conversation in thisdirection, however I wanted to have full disclosure when trying to trouble shoot.If I replace the heater fuse at the fuse box, it blows when I turn the ignitionkey. I was not sure if this could be related since the jeep ran fine prior toall of this, but at least wanted to throw that out there just in case.
    I can’t express my appreciation enough for you guys tryingto help me get this jeep back in service! I’ve got 10 days to meet the deadline for when family arrives and thankyou so much for the help!

  7. #27
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Thank you for your reply .
    the reason I stress " COMPUTER SAFE " is because I learned the hard way years ago why. We must test computer circuits with computer safe equipment .
    A NOID light just makes it easier in addition to being computer safe . The power for the injector circuit isn't a computer circuit but the ground circuit is . Many switched circuits that are computer feedback on vehicles are ground switched by the vehicles computer .
    Pin addition to a NOID light , the test light and even a multi meter . Any time we probe a wire that is potentially a computer feedback wire , we must use proper equiptment .
    An inexpensive multimeter that are givaways at harbor freight are NOT computer safe .
    i have an old sunpro / action automotive professional meter that is computer safe because it only draws less than 10 megaohms of impediance from a computer circuit .
    the test light must have a diode ( and marked computer safe ) that only draws less 1/4 of a volt from a. Computer circuit . If you use a 12 volt test light , you are trying to draw 12 volts to light the bulb from a circuit that only carries no more than 5 volts . You effectly create a surge that burns out the circuit . That would mean we would most likely rendered the vehicles computer inoperative , depending on the damage done . In my case , almost fifteen years ago , I overheated the pcm's voltage regulator . a multimeter has several ranges . The test light for computer safe that I have is good up to 28 volts LOW amperage . Not for starter or alternator .
    before making use of the ignition coil that was purchased , a test of the harness plug should be done . By the way , the PCM on your jeep is what powers the ignition coil . Yes , power does come from the alternator but the circuit is completed by the PCM . The advance/retard is computer controlled. We want to see if the plug gives any reading . Power from alternator , ground from PCM .
    primarily , we want to know if the coil is getting fed and if the injectors are as well .
    We want to know what is happening when the key is turned to START .
    upon writing this post , I didn't check back at earlier posts of it was in fact confirmed there is fuel pressure at the rail . At least , does the fuel sound when the ignition is turned ON.
    If injectors aren't firing , coil not energizing because no reading at coil harness , we move on to checking the PCM .
    noid light is easy to use . Just unplug a connector from an injector and plug in the NOID light . Crank the engine and see if it lights in a steady rhythm , an on and off pattern . This will mean the PCM is firing the injectors in a proper firing order , just like ignition wires do .
    Never overlook the obvious . It's usually right in front of us

  8. #28
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    When checking the ignition coil harness with the computer safe test light , a power circuit is checked with the alligator clip on negative battery terminal . When checking a ground circuit , the alligator clip,on battery positive .
    if you have the clip on positive terminal and no light is observed in one quick touch , don't keep touching it . You may be probing a power terminal . Switch to negative .
    Hence , if you have the clip on negative and one quick touch does not light , switch to positive . You may be probing a computer ground.
    Of course it is preferred to have a wiring diagram if can be gotten . Autozone and dealers are good about that . May be other stores as well . Hope the color codes I've posted correspond but they change from model one to another .
    just learned that harbor freight sells a computer safe test light that connects to battery positive and negative and automatically switches polarity . That sounds very useful in your need .
    Last edited by greg92jeepxj; 12-14-2016 at 04:11 PM. Reason: Addition
    Never overlook the obvious . It's usually right in front of us

  9. #29
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Hey guys the holidays are bearing down and I’ve been workingon the YJ intermittently as much as I can with all of your recommendations.


    Per your direction, I went ahead and pulled the ignitioncoil. All the bolts were pretty rustyand I had to cut the ones from the old coil to the mounting bracket.I included some pictures also.Unfortunately, I also had to cut the groundwire from the alternator to get the one bracket screw out.Since that is a monster cable I have to hooka new connector and possibly replace some bolts to get this thing hooked backto normal.This may entail solderingthat connection.


    Because my patience isn’t too good, I went ahead and hookedthings back up to see what would happen and plan to go back with new bolts andsuch once we solve this puzzle. So, I attemptedto start her up and pretty much had the same result.


    I did receive a crankshaft position sensor in the mail lastweek. I assume swapping that our may bemy next step?Another thing I noticedwas that the battery seemed weaker than normal.This was probably from all this cranking and being in the garage for 3months.I did place a trickle charge onit so that it should be good to go after work today.

    Thanks again for the continued guidance and support!!




    Attached Thumbnails Attached Thumbnails YJ turning over but not starting.  New fuel pump, sending unit, filter, rubber hoses-coil2.jpg  

    YJ turning over but not starting.  New fuel pump, sending unit, filter, rubber hoses-coilbesidenew.jpg  


  10. #30
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    And additionally I found a loose open wire where the 4 wheel drive is engaged. Not sure if this could be one of the culprits?

    Thanks again!
    Attached Thumbnails Attached Thumbnails YJ turning over but not starting.  New fuel pump, sending unit, filter, rubber hoses-4wheeldrivewires.jpg  


  11. #31
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    And I meant to also say that I purchased a NOID light and computer safe probe so I think I have what I need. Thanks again!

  12. #32
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    On the first picture post , the casing is clearly split and at the minimum , must have been arcing but what oil,is packed from the factory is long gone . Give it last rites and pitch it .
    On the second picture post , that's the front axle shift motor . Won't have any bearing on the no start . When it's up and running , that'll be another project . Doesn't look functional as it sits .
    Once the coil is bolted up and the wiring repaired , back to looking for a voltage signal from the harness plug with the newly acquired computer safe test light . Once that's sorted out , the NOID light will get a work out . Come on little YJ , you can do it ! There's always room for a Christmas miracle !
    Never overlook the obvious . It's usually right in front of us

  13. #33
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Thanks greg92exj, superj, & 69jeepcj for hanging with me and advising me through this exhaustive process. I did the key computer trick a couple weeks ago and all I remember was 12 and 55, however I will run it again now with a new battery and coil. Maybe something has changed.


    I wanted to mention (because this is my first jeep) when I purchased this rig from my uncle (he had it 7 years and had bought it from an auction) that was a bonus for me so I had a little history to go on.


    He had changed the distributor, spark, plug, and wires less than a year ago because something came loose and sprayed oil all under the hood. He cleaned it up pretty good and as I mentioned it ran GREAT in the Carolina heat and cold. He had a slightly oversized battery also. I changed that out to what the manufacturer called for this past spring/summer. When I noticed it dragging (probably from sitting for 3 months) I took the battery back yesterday and got another one like he had with a longer standby and CCA.


    One thing he mentioned was that when it rains, the check engine light may come on and when it dries out it will go off. This has been true. It still runs fine, but wanted to throw that out there. Its been dry now for a while so I don't have this issue. Also, he said to never "bump" the little computer under the dash. I included a picture. He said to never take the zip tie off or it wont run. When I called him recently about it, he asked if the fuse had worked its way out or not. It seems secure to me. I am guessing that most jeeps have a cover over this but all I know is if the little red light is on then its good to go.


    I noticed when I put the new battery in yesterday the little red light was shining bright. The other thing is that I was attempting to "test" everything prior to securing the gas tank back in case I had made a mistake somewhere. It all appears to have fuel coming around the recommended psi and I am smelling fuel under the hood which I hope is a good sign. Or maybe its flooded? I read a post about somehow fuel got into the oil and that was preventing the start etc...

    I have an aftermarket CPS I could try but I hear unless its mopar to not use it. I cant seem to get up in there enough to get it torqued out anyway.

    At any rate, you guys are class act jeepers trying to help me through this. It doesn't look like I will meet my deadline for a Christmas eve ride at this point but I sincerely appreciate all the help and direction. I'm not a very good mechanic but as frustrating as it is, this has been therapy for me away from business life. I have a few hours tonight and a few hours Thursday evening to troubleshoot before the wife summons me to begin preparation for family coming over. If ya'll can give me a list, I'll check it twice... and I hope I've been good enough this year to get this old YJ back on the road and hit the trails for 2017!

    Thanks again!
    Attached Thumbnails Attached Thumbnails YJ turning over but not starting.  New fuel pump, sending unit, filter, rubber hoses-computer1.jpg  

    YJ turning over but not starting.  New fuel pump, sending unit, filter, rubber hoses-computer2.jpg  

    YJ turning over but not starting.  New fuel pump, sending unit, filter, rubber hoses-fuses2.jpg  


  14. #34
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    I cannot identify that " module " , I'll call it , or its purpose. I'll have to say it's an add - on since its zip tied and fastened with sheet metal screws . Can't find it on a FSM ( factory service manual ) . Curiously , we would be interested where it's wiring goes and connects . Ok , a oil pressure sending unit switch was replaced due to a major leak ( typical) and trashed the distributor ? That being replaced , the engine ran afterwards .
    at this time , the coil would of course be the next repair / installation and the wiring harness connector and ground wire spoken of. Any ground connections should always be cleaned anywhere they exist to make certain a complete circuit is made .
    Test light can be used to confirm good grounding afterwards .
    With a good battery charge , it will be time to resume testing . Time to break out the NOID light and computer safe test light . We are looking for on/off pulse of the NOID light as engine cranks .
    with ignition on , ignition coil harness plug disconnected , we are looking for power from one terminal and ground from the other . Keep in mind the coil harness negative feeds back to the PCM . Regardless , all test light procedure for the diagnostic procedures performed here will be made with the computer safe test light . Computer feed back or not , your new test light is safe to use for all EXCEPT a high amperage circuit such as an alternator or starter CRANKING circuit . A starter solenoid wire can be tested with it . That's low amp. The test light may have a warning disclaimer not to use on high voltage circuits .
    Before this however , please check and verify all fuses , under the hood and under the dash.
    The ignition fuse under the dash ishould be checked . Don't remember was that for the cranking circuit , which works . Good to check ( ignition switch in ON position ) fuses on both terminals to ensure connectivity of voltage flowing from supply and into the circuit . Of one side reads good and other side dosen't , that will have to be investigated . I believe you already have a problem on the blower motor circuit , previously posted .
    Looking forward to results positively . Post when you can . Thanking you in advance .
    Never overlook the obvious . It's usually right in front of us

  15. #35
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    that looks like some kind of alarm. I don't remember anything like that on either of the yjs the wife and I had. that could be your trouble.
    no more jeeps at this time. next time it will be a cj with a v8

  16. #36
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    Trace the wires to the module. Could it be a remote starter? Being cracked it may be damaged causing the no start issue.

    Just a thought.
    "Never look down on anybody unless you're helping him up" - Jesse Jackson

  17. #37
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Yesterday it was 60+ degrees in Carolina so after lunch I went home to play with the Jeep. I decided what the heck, I have the new aftermarket (Standard) Crankshaft Position Sensor why not throw that in there and see what happens. After all, its not running anyway so what could it hurt?!?

    It took me about 45 minutes from start to finish. While doing this, I removed the battery tray to begin inspecting the heater blower fan so I can work on that next. The replacement on that was different with the wires being on the outside, so im debating if I want to do that 73 bronco upgrade or whatever for more air.

    But, back to the crank no start issue as that's the first priority...get her running! After priming the pump, it happened!!! She started and ran! After 3+ months of agony, I let it run in my garage and the exhaust fumes smelled so good!

    http://www.youtube.com/watch?v=ed9Ipmuk0iY

    I got a neighbor to help get the gas tank back in and secured and this YJ is nearly ready for its rebirth! I need to get the heater blower fixed (blowing heater fuse) is next on the list, but at least it runs and we are in business again.

    I cant thank you Jeepers enough for helping me through this! Looks like Santa must think I was good this year! The jeep ride is ON for the girls!

    Cheers to you all!
    Attached Thumbnails Attached Thumbnails YJ turning over but not starting.  New fuel pump, sending unit, filter, rubber hoses-celebrate.jpg  


  18. #38
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Glad you got it fixed!

    Merry
    Merry


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  19. #39
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Celebration time ! You earned it ! The promise to take the kids out for the Christmas Eve ride will be kept , as promised . Miracles do happen and you worked hard for it to come true . Yes , a very merry Christmas to you and family !
    P.S.- after the holidays , when the weather is good , maybe spring , I know you'll have more to do . We can make a list of checks and recommendations . For now , ENJOY !!!!!
    Last edited by greg92jeepxj; 12-23-2016 at 04:01 PM.
    Never overlook the obvious . It's usually right in front of us

  20. #40
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    Re: YJ turning over but not starting. New fuel pump, sending unit, filter, rubber ho

    Thar sensors, its always that dang sensor. :)
    no more jeeps at this time. next time it will be a cj with a v8

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