Search the Community

Showing results for tags '2.5l tbi'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Forums

  • Let's Talk and Share!
    • Topic Searching, Posting Attachments and Other Forum Tools
    • 4WD Mechanix Magazine 'Tech and Travel' Forums: Member Photo Gallery
    • General Repairs and Tips (See Other Forums for Specific Vehicle Topics)
    • Sharing New Products
    • Health and Fitness for Four-Wheelers and Powersports Enthusiasts
    • Off-Topic and General Discussion
    • Calendar Events and Outdoor Activities
  • Buy, Swap and Sell Classified Ads
    • Motor Vehicles, Trailers and OHV Classified Ads
    • Parts for Sale, Swap or Wanted
    • Equipment and Tools Classified Ads
  • Jeep® 4WD Owners Group
    • Vintage Jeep® Vehicles 1941-71
    • 1972-86 AMC/Jeep® CJ and Jeepster Models
    • Jeep® YJ Wrangler, TJ Wrangler and LJ Wrangler
    • 2007-Up Jeep® JK Wrangler 4x4
    • Jeep® XJ Cherokee, MJ Comanche Pickup and Grand Cherokee
    • FSJ Models: Full-Size Jeep® Gladiator and J-Truck, Cherokee, Wagoneer and Grand Wagoneer
    • Jeep® Liberty, Commander and Patriot
  • Dodge Power Wagon, Dodge and Ram 4WD Trucks
    • Dodge 4x4 and Ram 4WD Trucks
    • Dodge-Ram Cummins Power
  • Chevrolet & GMC 4x4 Trucks and SUVs
    • Vintage to 1991: Chevrolet & GMC NAPCO and K-Model 4x4 Trucks
    • 1987-Present: Chevrolet & GMC Silverado, S-Trucks and 4x4 Suburban, Yukon and Blazer
    • Humvee and Hummer H1, H2 and H3 Forum
  • Ford 4x4 F-Series, Full-Size SUV and Ranger Trucks, Bronco II and Explorer
    • 1948-Present: Ford F-Series Trucks
    • Ford Power Stroke Diesels
    • Full-Size Ford SUV, Bronco 4x4, Excursion and Expedition
    • Ford Ranger, Bronco II, Explorer and Mercury Mountaineer
  • International-Harvester 4x4 Light Trucks, Scout and Scout II
    • International-Harvester 4x4 Light Trucks, Scout and Scout II Forum
  • Toyota Truck, Land Cruiser, FJ Cruiser, Toyota SUV and Lexus 4WD
    • Toyota Sequoia and Lexus, Land Cruiser 4WD: FJ, DJ and FJ Cruiser
    • Toyota 4WD Pickup, Hi-Lux, Tacoma, Tundra and 4Runner
  • Datsun and Nissan 4x4 Trucks, Pathfinder and Xterra
    • Nissan Patrol, Pathfinder, Xterra and SUV 4x4s
    • Nissan 4WD Pickups: Datsun, Nissan, Frontier and Titan
  • 4WD Land Rover Community
    • Land Rover, Discovery & Defender 4x4s
  • 4x4 Suzuki Samurai and Sidekick/Geo Tracker
    • Suzuki 4x4 Samurai
    • Suzuki Sidekick and Geo Tracker
  • Isuzu Trooper, Trooper II, Rodeo, Amigo and Isuzu 4x4 Pickups
    • Isuzu Trooper, Trooper II, Rodeo, Amigo and Isuzu 4x4 Pickup Forum
  • Quad ATV, UTV and Side-by-Side 4x4s
    • 'Quad' ATV, UTV and Side-by-Side 4x4s!
  • Dirt & Dual-Sport Motorcycles
    • Dirt & Dual-Sport Motorcycles
    • Dual-Sport and Dirt Motorcycle Equipment for Overlanding
  • 4x4 and Single-Track Travel & Adventure Destinations!
    • Places You Have Been...
    • Places You Would Like to Travel!
    • Off-Pavement Travel Gear
    • Equipping Your 4x4 for Overland Travel
  • Travel Trailers, Toy Haulers, Tent Trailers and Military Surplus Trailers
    • Travel Trailer and Toy Hauler Forum
    • Military Surplus M415, M416 and Other Off-Road Trailers
    • Tent Trailers and Trailering
  • Welding, Metal Fabrication and Metallurgy Discussion
    • Welding and Metal Fabrication Forum
    • Metallurgy and Heat Treating Forum
  • The Right Tools and Equipment
    • Garage Tools and Equipment
    • Diagnostic and Specialty Tools & Equipment
    • Tool and Equipment Sources

Found 10 results

  1. I hate to bring this up again, but I need help. I have a 1990 2.5 TBI wrangler that is killing me! I say I've been throwing parts at it, but given it's age everything I've done was either bad or well on its way. Now that almost everything has been replaced including the IAC I need help adjusting it. I assumed the IAC was in the correct position when I replaced it, but I'm suspect the PO had adjusted it when some of these parts I replaced went bad or possibly when they plated off the EGR (I replaced the egr and cleaned the egr tube) and now I find myself trying to adjust the IAC. I've adjusted it twice. The first time I was very close, but was not perfect so I adjusted it a turn more and it's acting up again. I've ready your very helpful advice, but call me slow I could use a bit more help or even pictures on how to do it the way you describe. The adjustments I made were before I found this page and I was told to just unplug it adjust it to 3500 rpm turn it off, plug it in, start it up for a minute then reset the ECU and I'd be good to go. Which is "close" to what I read here but miles away too. It did make it much better, but one more turn and it's back stalling out again. Can anyone give me pictures or better yet a video? I've hardly been able to drive the jeep since I purchased it.
  2. Here is 1987-90 Jeep YJ Wrangler and Jeep XJ Cherokee/MJ Comanche 2.5L TBI diagnostics information in PDF form. The first document includes all sensor and switch tests plus adjustments that affect engine tune, idle and reliability. Wiring schematics and ECU pin locations, test plugs and diagnostics included. Jeep 2.5L TBI Complete Diagnostics-Sensors-Switches.pdf Jeep 2.5L TBI ECU Inputs and Outputs.pdf Jeep 2.5L TBI MAP Sensor Test.pdf Jeep 2.5L Timing Chain and Tensioner.pdf Jeep 2.5L Valve Timing Check.pdf Jeep YJ 2.5L TBI Sensors and Pinout.pdf YJ Wrangler 2.5L TBI Wiring of WOT to ECU.pdf Jeep YJ 2.5L ISA Wiring Diagram.pdf 1987-90 2.5L TBI Intake Manifold and Sensors.pdf 1987-90 YJ Wrangler 2.5L TBI Emissions System Parts.pdf YJ Wrangler Fuel Filter and Guard.pdf 2.5L TBI ISA Motor Adjustment.pdf Used in conjunction with the many forum exchanges (search under "All Content" and "2.5L TBI" in the search box), plus the Jeep 2.5L TBI troubleshooting article at the magazine website, this information will help solve your Jeep YJ Wrangler or XJ Cherokee 2.5L TBI troubles. In references, the Model 81 is the Jeep YJ Wrangler. The Model 60/70 is the XJ Cherokee and MJ Comanche Pickup. Moses
  3. T-shooting an intermittent starting problem. About 80% of start-ups are perfect. When failing to start, it will turn over and over, but won't fire up. Sometimes starter fluid will cause it to fire up and then it runs fine, but that's only 50% effective. The rest of the time, only push-starting will work, but push-starting does work every time. Most obvious assumption is fuel problem, but fuel system checks out fine (replaced almost everything over time anyway). Ignition/electrical is fine. Also, the problem seems to be completely independent of outside and engine temperature. I started reading about ECU inputs, and discovered that during startup, an engaged WOT switch causes ECU to cut off fuel because ECU thinks it will flood the engine. The WOT switch is worn, but shouldn't prevent starting if disconnected. Would any other ECU inputs prevent fuel flow during start-up if their signals are outside normal limits? Service manual says during "Ignition On", CTS, MAT and MAP sensors begin providing input to ECU, but doesn't list MAT or MAP sensors during actual start-up. See attached page. So which sensors matter to ECU for start-up fuel supply calculations or decisions? Also, during push-starts, the ignition (key switch) is in the Run position, and not the Start position, which changes the ECU inputs, too. My shop has a DRB II diagnostics reader, but unless they hook it up when it happens to be misbehaving, shouldn't everything check out ok? Unfortunately, I've never been able to get it to fail at the shop. I also tried replacing the fuel relay. I also noticed that it is no longer cycling the ISA motor when it fails to start. It used to, but I can't figure out why it did that anyway. What are my next moves? Might be trying to oversimplify this, but what kind of intermittent problem would occasionally prevent a normal startup, but NEVER prevent a push-start from succeeding?
  4. I put a new 2.5l into the jeep and it only has 400 miles. It was running great till suddenly the issues popped up again. I hooked the scanner up and saw that the short term trim was ridiculously high. Its reference point at idle is 128 and its running at 180. The long term trim is at 109. the injector pulse is 2.0. The o2 sensor was reading no higher than 500mv.
  5. Hi, I have a 1988 Jeep Yj 2.5 with the renix computer. My last stop before I drive this thing off a cliff is here. I should have come here first. I hope one of you can help me. I love my Jeep but am so frustrated with it right now. Problem: Jeep is running super rich. I do not think it is ever coming out of closed loop. Points to know: - O2 sensor is recognizing that the jeep is rich. Volts sit between .94V and .99V JEEP RUNS AWESOME. No loss of power. No hesitation. Idles between 900 and 750 - Fuel smell coming from the tailpipe Emissions high on HC and CO Things I have tried: -Replaced o2 sensor -replaced fuel pressure regulator -replaced CTS replaced ISA replaced ECU replaced MAP Replaced MAT checked return fuel line for blockage. Had Head rebuilt. Vacuum was fluctuating and needed new valve guides. Was hoping this was impacting the MAP sensor. Nope I have gone through entire FSM diagnostic tree. The only thing that failed was the MAT sensor resistance never got down to 150ohms. Always stayed above 300. I even paid a mechanic $600 to try and uncover the problem. He confirmed it was not coming out of closed loop. Recommended changing the ECU. Which I did. I hope someone can help. Thank you all in advance. Carlos
  6. Hello im new to this i am from hawaii i have a 1989 jeep wrangler and have a brand new motor installed it had an idle problem so i changed the tps set it in between 4.6 and 4.7 on the multimeter which is what the dealer said to set it as and it runs for ten minutes and as soon as i tal the gad it sputter then dies any ideas ?
  7. I'm at my wits end troubleshooting my lil 2.5L engine. I googled and found your page from about a year ago. 1990 jeep wrangle 25l engine timing. Today I thought about timing. It misses, like running on only 2 cylinders when at low speed and and only pulling slightly. As I move into mid and upper rpm range it stops missing. I still do not have much acceleration but at least it stops missing. I've check and/or changed every sensor it has. TPS is only rough since I have not gotten my laser tach to work yet. In checking fuel I have only 10 psi so I know that's a problem. This started about a month after the SMOG guy changed the O2 sensor to pass smog. I've check the voltage when hot and it's within spec. I also had massive exhaust gasket leak so I cleaned the surfaces and replace the gasket. I'm a machine mechanic from way back in the Navy so I'm not just a new mechanic. I just can't quite figure this one out. I'll check timing tomorrow. Lowell
  8. Thanks for the engine information. Ok .... update for today. I'm really not finding a vacuum leak and before I build a smoke machine there's been this gnawing in the back of my mind to check the valve timing. I found this pdf manual http://oljeep.com/JeepEngines.pdf and on page 63 it tell how to check valve timing. So I removed all the plug, it was easier to rotate by removing all the rocker bridges, set up a dial indicator on the #1 intake push rod and checked .... Hmmm the dial moved .010 but I don't see the index mark anywhere (????) ... oh, there it is 3 inches to the left, or 3 inches BTDC ... really???? Guess I'll pull the timing cover and check it out.
  9. In the second pic I know the line at arrow #1 goes to the air cleaner. Can anyone tell me where #2 and #3 should go? first pic is just a close up of the connections in question. Thanks
  10. My 88 Comanche 2.5 liter doesn't have a wot sensor did some of them not come with them or maybe some one took it off when I wasn't looking