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About 2point5liter

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  1. Hmm...really interesting. I'd hate to have to pull the harness out again! but if I need to at any point in the future that sounds like it'd be really helpful, thank you! Advance honored their 1yr warranty, so I got a new ECU in, and it's running great, idling as it should and adjusting as needed to keep a nice idle. I haven't gotten a real ride out of it yet though, waiting until I have some backup to call if I end up broken down on the side of the road, until AAA can get to me. However, when putting the harness back in to test the new ECU, I noticed something I hadn't noticed before.
  2. Well, I checked everything in the harness. It all checked out in my continuity tests, meaning, I got sold ANOTHER bad ECU. I wish I had a friend with the TBI 2.5L wrangler so I could check and make 100% sure, but hopefully Advance Auto fulfills their 1 year warranty after I told them I had to do the same with AutoZone when I picked this one up. If not, I'll use that part number you gave me and find a more reliable source. Thanks! Ill check back in after I get my vacuum lines back on, my harness cleaned up and installed, and my new ECU in and installed. Looks like I still have a lot of
  3. Thank you! I love this Jeep, It was my first vehicle, bought it barely running for $850. It makes me mad at times, but I wanna see it up and running again. I'll keep that in mind with the grounds, because something is going wrong here. I forget if I mentioned it or not, but this will be my 4th computer actually. I get them from Advance, remanufactured from a company called "Borg Warner" I think. the issue the first time was my Power Steering Pressure Switch broke off and melted against the exhaust manifold, causing a short. it blew my ECU, the wire leading to my fusible link, and the f
  4. I dont think I have a check engine light on my 89. I do have the diagnostics terminals though, and have been using them to help troubleshoot. I checked the fuel pressure and it was good, so the next thing I did was pulled the wiring harness out. I can't see much that's bad, but I can see that someone else already had this thing out, and used duct tape instead of electrical tape in all the spots where multiple wires connect. Unless it came like that from the factory? That would be awful. Anyways, im currently trying to organize this mess, using nails and rubber bands with it laid ou
  5. I didnt test the fuel pressure, but im positive it isnt that. It's gotta be either the wiring harness or the ECU, because high fuel pressure wouldnt cause the jeep to run well for a brief period then return to poor idle. it also would not have gone from good to immediately bad like it did. Im gonna tow it home, pull the wiring harness, pull it apart and start looking for some burned up parts. if I cant find anything, it's time for a new ECU, even though it doesnt look or smell burned at all. Maybe it still is.
  6. I ended up re-checking my Coolant sensor and my MAT sensors. They were both open. It turns out, when I checked them, I had rushed it. They read ~4M ohms, but I had thought they read 4k ohms. Retested this time and they were anywhere from ~5.5M ohms to ~18M ohms. replaced both, leaving them outside the Jeep with the old ones still screwed into the intake. No improvements. I am almost positive that the injector isn't bad because I am now using my old one, and it's working the same as my new one did, I have swapped them a few times. I haven't been able to test the fuel pressure yet, but
  7. Okay, I retested the injector voltage this morning, because I was tired and aggrevated yesterday when testing it. The wire in question, is a light blue wire running all the way from pin 21 of the ECU to the injector, connecting to nothing in between. So to rule out a short in the wire harness, I cut the wires at each end and spliced in a wire of my own running outside of the Jeep, separate from the rest of the harness. No change. This is what the wire looks like now. [ECU PIN21]---|Splice1|----------------------------|Splice2|---[injector] SO, when the Jeep is off, it reads 0v
  8. I tested the TPS sensor attached to the throttle body, with the throttle body off the Jeep. I brought it home and my dad used a 5V source to test it, so I know that's good. What I did today was cut the wire at the ECU pin 21, and the wire at the injector that it leads to, and soldered a wire between the two to rule out a short in the harness. It acted strangely. It still read 3.7 @ both the ECU and the injector and it was still flooding itself out. but then it started to run properly for a minute, as it had before. it tested 12v at the injector and the ecu. it then started floodin
  9. Thank you for the replies! I wish I found this community a little sooner. but of course it's only after I make a topic that I see some progress finally! Something really odd happened when testing everything today. I had it idling with everything vacuum related plugged up, just to see if it was the intake manifold gasket. It still had almost no vacuum, and was still idling very low. However, it started to run properly, building up plenty of vacuum and everything. So I knew it was most likely not mechanical, but rather electronic. However, it returned to idling poorly and low vacuum afte
  10. I did test it with a gauge and got a good reading. But I just remembered that it was right before this issue was occuring. I'll have to retest tomorrow, along with a leakdown test.
  11. a huge problem with my YJ brings me to this forum, so I'm a new member. I own a 1989 Wrangler YJ 2.5L 5-speed. It's a '94 block, with the '89 accessories/head/etc. I drove my Jeep to work one day a couple weeks ago. No issues. Went to leave to grab some lunch at a local restaurant and it started idling not well in about 20 seconds after starting it up. Tried to just drive it anyways, and the power would completely cut out as if I were idling, even though I had it almost floored. The RPMs would go from ~2500 down to ~1000 where it would stay until I got off the gas, when it would die. I
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