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91 YJ Won't start

Discussion in 'Wrangler YJ (1986-1995)' started by vlkski, Jan 17, 2017.

  1. Jan 17, 2017 at 11:31 AM
    #1
    vlkski

    vlkski [OP] Member

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    Vic
    Houston, TX
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    91 Wrangler YJ
    2 inch body lift
    I purchased this a few months ago and have had nothing but problems keeping it running since I got it. It turns over, but won't start. I have replaced the plugs, wires, distributor cap, coil, and had the ECM rebuilt. It had been running fine for a while. Then the clutch went out, so I pulled the transmission and changed it. When I put it all back together it turns over and won't start again. I thought it might be CPS so I replaced it, but still nothing. I really need some help!

    Thanks,
    Vic
     
  2. Jan 17, 2017 at 4:38 PM
    #2
    C2T

    C2T Well-Known Member

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    Richard
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    2.5" AEV Dual Sport lift, 35" Treadwright Guard Dogs, Black Rock Wheels, AEV Front & Rear Bumpers with Tire Carrier, Fuel Caddy 10 gal. Aux. fuel tank, Warn 9.5ti, 125' synthetic winch line, front axle skid, 20" LED light bar , Bilstein Shocks, steel steering skidplate,
    Hi Vic! While you indicate you replaced a bunch of stuff, like the plugs and wires for example....you don't indicate if you actually have spark or not. Did you check fuel pressure at the rail? Are the plugs getting fuel on them when you crank it? Have you given it a shot of ether to see what happens? Just some ideas.....
     
  3. Jan 18, 2017 at 8:29 AM
    #3
    vlkski

    vlkski [OP] Member

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    2 inch body lift
    Thanks C2T I have checked for spark before, but not this time. I had not check the fuel pressure. What is the best way to do that?
     
  4. Jan 18, 2017 at 5:51 PM
    #4
    HotRodN

    HotRodN Active Member

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    Bumper, winch, fender flares. Stock ride height for now.
    C2T is right,,,, check for spark first,,, then fuel,,, if you have both it should fire. I've used a timing light to check for spark so as not to get that dreaded jolt when ya hold the wire,,,, not sure how to check fuel pressure unless you can find a place to install a gage or you can just open up the line someplace and see if fuel comes out. Don't be near a hot spot when ya do LOL. Can you hear the fuel pump come on when you turn on the key? Do you have the throttle body injector atop the manifold or multiport injection? On the throttle body you can look down while someone cranks to see if fuel is getting into the system. If it's multiport man I don't have a really good way to check them other than C2T's suggestion to pull a plug or 2 and see if it's wet from fuel.
     
  5. Jan 18, 2017 at 6:09 PM
    #5
    C2T

    C2T Well-Known Member

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    2.5" AEV Dual Sport lift, 35" Treadwright Guard Dogs, Black Rock Wheels, AEV Front & Rear Bumpers with Tire Carrier, Fuel Caddy 10 gal. Aux. fuel tank, Warn 9.5ti, 125' synthetic winch line, front axle skid, 20" LED light bar , Bilstein Shocks, steel steering skidplate,
  6. Jan 19, 2017 at 7:50 AM
    #6
    vlkski

    vlkski [OP] Member

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    2 inch body lift
    Thank you both. This my first Jeep and I do not have any experience working on them. I grew up working on Mopars with my Dad, but this is different. I'll get a pressure gauge tonight. I have got figure out what's wrong with this.
     
  7. Jan 19, 2017 at 1:41 PM
    #7
    C2T

    C2T Well-Known Member

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    2.5" AEV Dual Sport lift, 35" Treadwright Guard Dogs, Black Rock Wheels, AEV Front & Rear Bumpers with Tire Carrier, Fuel Caddy 10 gal. Aux. fuel tank, Warn 9.5ti, 125' synthetic winch line, front axle skid, 20" LED light bar , Bilstein Shocks, steel steering skidplate,
    Just keep in mind...we are shooting in the dark and just throwing out possibilities.

    Many of the car parts houses (O'Rielly Auto Parts, Napa,...etc) have tool loan programs where you can borrow tools like a pressure gauge for testing. It can help save a buck here and there.
     
  8. Jan 23, 2017 at 6:25 AM
    #8
    vlkski

    vlkski [OP] Member

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    2 inch body lift
    Thank you both! C2T I got a fuel pressure gauge from Oreilly. Fuel pressure looks fine. I am not getting any spark to the distributor. What do I test next? I am not the greatest at electrical.
     
  9. Jan 23, 2017 at 7:57 AM
    #9
    OFFGRID

    OFFGRID Well-Known Member

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    Peter
    Houston
    Vehicle:
    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    Is this a 2.5L or 4.0L? Was the Jeep running before you replaced the ignition components mentioned above and then did it run afterwards? I'm trying to get a timeline of the repairs/changes that you made in my head and when the Jeep quit running i.e. (Motor running, replaced clutch, Jeep not running, replaced ignition components, Jeep still not running) or (Jeep running, replaced ignition components, Jeep still running, replaced clutch, jeep not running) Spark or fuel? You are getting fuel so it is spark. You said that there is no spark at the distributor, How did you test this? Did you pull a plug wire and hold it near the block to see if you get a spark? Did you try to pick it up with a timing light? Did you replace the rotor under the cap as well? Could you have forgotten to reinstall the rotor? Are all of your plug wires tight especially the one that goes from the coil to the distributor.

    Answer some of these and I can try to figure out what the next step is. Where in Houston do you live?
     
  10. Jan 23, 2017 at 8:16 AM
    #10
    vlkski

    vlkski [OP] Member

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    91 Wrangler YJ
    2 inch body lift
    OFFGRID thanks for all of the questions. I hope i can answer them all. It's the 2.5. It was running when I bought it. On the drive home I stopped for gas and it wouldn't start. That was the battery cable was loose. Then it ran fine for a few days. It died on me while I was out. That is when the the coil to the started was changed. Again it ran fine for a month or so. My wife was at the store and she came out it wouldn't start, so I change the plugs, wires, distributor cap, and rotor in the parking lot. It still wouldn't start. After towing it home I sent the ECM off to be rebuilt. When I got it back and replaced it everything was running fine. Then the clutch went out on the way home from work, but it was still running fine. Once I changed the clutch and reinstalled the transmission it turns over, but won't start. I thought it might be the Crank position sensor because I had to remove it when I took out the transmission, so I bought a new one. Still turns over, but doesn't start. So I have fuel pressure, but no spark to the distributor cap. I used a tester from the cap to the wire from the coil to check for spark. I'll double check all if the wires again, but they were all tight. I make sure of that when I put them on because I have made that mistake before.

    I live in Friendswood.
     
  11. Jan 23, 2017 at 8:36 AM
    #11
    OFFGRID

    OFFGRID Well-Known Member

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    Peter
    Houston
    Vehicle:
    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    I had very similar experience with my CJ. After replacing everything but the distributor itself it turned out to be the Stator in the distributor. When they go out the jeep will die and sometimes let you get where you are going and then not restart until it cools off usually more than an hour later. I replaced the distributor and fixed all my problems with the ignition system. If you did any work on the Jeep with the key on for extended period of time, there is the possibility that the coil overheated and fried. I've read that can happen if the points are making contact when you shut the motor down. If you have a test light or a meter Check the positive terminal at the coil to make sure you are getting voltage to the coil itself. I've read that some of the older Jeeps are reduced to 9V while others I believe get 12V at the coil. I'm not sure what you will get.

    I'm in Bellaire.
     
  12. Jan 23, 2017 at 8:55 AM
    #12
    vlkski

    vlkski [OP] Member

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    2 inch body lift
    Thanks! I'll check that. It could be the coil because my youngest daughter was helping me and I noticed too late that she had left the key on. By too late I mean the battery went dead. We were working on it yesterday and she did it again, but I caught. I reminded her not to leave the key on.

    After checking the coil I'll replace the distributor.

    Bellaire isn't to far away. I work off of I10 & 59. Where to do you go off road?
     
    C2T likes this.
  13. Jan 23, 2017 at 9:18 AM
    #13
    OFFGRID

    OFFGRID Well-Known Member

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    Peter
    Houston
    Vehicle:
    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    The only places I know within a 90min drive all have mud, but General Sam's in Huntsville has the least mud most of the time. I belong to Southern High Rollers (SHR) 4X4 club. We are going to Wolf caves near Mason Tx (4hrs away) for a weekend trip the weekend of Feb 25. I've never been but hope to make it there. My Jeep is upgrading to a TH350 automatic and NP208 T-case.
     
    Last edited: Jan 23, 2017
  14. Jan 23, 2017 at 9:37 AM
    #14
    vlkski

    vlkski [OP] Member

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    2 inch body lift
    I've got to get this rig running more dependably before I can take it off road. I plan to do a lot to it, but baby steps. I've looked into General Sam's before, but never been there. I been to DSO and Extreme in Crosby.
     
  15. Jan 23, 2017 at 10:44 AM
    #15
    OFFGRID

    OFFGRID Well-Known Member

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    Houston
    Vehicle:
    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    DSO was shut down by the county. I called them back in May and they were not sure when/if they were going to reopen. I haven't been to extreme, but I hear it is all mud with no climbs or obstacles. I'll put up with mud to get to a climb or obstacle, but I'm not into mudding itself.
     
  16. Jan 23, 2017 at 10:48 AM
    #16
    OFFGRID

    OFFGRID Well-Known Member

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    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    There is a place called Creekside on 59north somewhere near Shepherd, TX.
     
  17. Jan 29, 2017 at 2:10 PM
    #17
    vlkski

    vlkski [OP] Member

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    91 Wrangler YJ
    2 inch body lift
    THANKS! It was the coil.
     
  18. Jan 29, 2017 at 8:54 PM
    #18
    OFFGRID

    OFFGRID Well-Known Member

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    1979 Jeep CJ7, 258, TH350, NP208
    Howell fuel injection, header, HEI distributor, TH350, NP208, SOA lift with YJ springs in the front & GW springs in the Rear. AMC20 with G2 1 piece chromos trussed, Dana 30 with G2 chromos and 760x ujoints and MM Stainless Hubs, Geared 4.56. Tom Woods shafts, Metal cloaks, Caged, 37" Toyo MTs.
    Cool. Glad you fixed it.
     
  19. Feb 1, 2017 at 10:29 AM
    #19
    vlkski

    vlkski [OP] Member

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    Vic
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    91 Wrangler YJ
    2 inch body lift
    Again thanks for the help. When I was changing the clutch I realized the body lift that is on it was not installed properly. I want to fix it. While I am doing it the plan is to replace the body mounts. What would you suggest for body mount bushings?
     
  20. Feb 1, 2017 at 10:33 AM
    #20
    vlkski

    vlkski [OP] Member

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    2 inch body lift
    Should i post that as another thread?
     
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