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Showing results for tags '2.5l jeep'.
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Hey Guys. I have enclosed a link to the noise this engine has. I have not been able to figure this one out. Here's a little history and the diagnostic procedures used so far. https://www.youtube.com/watch?v=Oa12bVGEOwU&feature=youtu.be This engine is a "refresh". It's in a 98 TJ that blew its engine. I pulled this engine from a pull-n-pay out of a Dakota. When I tore it down it was clear the chain tensioner had destroyed itself and gone through a couple bearings. I did a complete refresh on the Dakota engine. Took it down to the block and thoroughly cleaned it with electrolysis, warm solvent soak, pressure wash, soap and water cleanup of all passages. Cam bearings, dingle hone cylinders, all new bearings throughout, new rings-properly clocked, new lifters, new pushrods, Cleaned and lapped the heads (valves). New intake and exhaust valves on #4 cylinder. New oil pump. The old cam and crank were fine so I used them. The engine runs great and has good "pop" for a 4-banger. It runs smooth with no misses. I broke it in and drove it around a bit so the computer could relearn the fuel trims and to get some back-pressure on the rings with some semi-hard slow pulls. The noise is deep in the block and toward the rear. Specifically it seems to be mid-block and around the #3 or #4 cylinder. The noise is its worst at idle. With even a slight throttle change it disappears. It doesn't knock at anything but idle. I cut-out (killed) each cylinder and it did not change the sound. I really suspected a lifter was not charging. Indicators were the location of the noise and the fact that it went away with 'any' acceleration (thus charging the lifter with a touch more oil pressure). I suspected a weak lifter and ruled-out everything else, so I replaced the lifters. Same sound. I took the pan off. No metal in the pan. Pulled the break-in filter apart. No metal in the filter. It has 40 psi consistently at idle (rises with acceleration). (10W30) With the pan off, I checked each rod on all four quadrants=no movement. I pulled the caps off #3 and #4 rods and the bearings are perfect. I suspected piston slap. Moved the pistons through their range, examining each. At the top of the stroke (rotating the engine back and forth) I watched the piston skirts for movement [because the force axis on the piston changes]. There was no lateral movement. The #4 piston had "maybe" a 16th of an inch lateral movement at the bottom of the skirt. (It was barely perceptible). I don't believe this is enough to cause piston slap. The engine has no noise upon startup, and begins this knocking after about 30 seconds usually. It doesn't seem to change with engine temperature. I went back to the top of the engine and pulled the valve cover. All the rockers were tight. I ran the engine and pressed down on each valve. There was no "clacking" or any indication there was any play in any valve. I can take/post more videos if it would be helpful. I think that about covers it. Hopefully I've included all the variables. I'm out of ideas! Any help would be much appreciated! Thank-you! -
Hello all. I have a 1990 jeep wrangler with a 2.5l 4cyl engine. The engine is young, only 4 or 5 thousand miles on it. However the rest of the drive train has 264,000 miles on it. Anyway the saga continues after adding new rear leaf springs. After the replacement on the way home this noise happens only when I let off the throttle. I think the ride hight is higher than what the stock was. But that should still not cause this noise Right? My question is what the stock springs should be just to verify I have the right springs and and what the awful sounds coming from the transfer case. Transfer cases are a bit of uncharted territory for me I'm unfamiliar with it. I have a video included. What shall I check first? -
Hi Guys! I've scoured these pages the last couple days, but can't find anything that matches my specific dilemma. I have a 1990 Wrangler w/ 150k miles on it, recent acquisition by my future son-in-law. It was running relatively fine, but it quit suddenly on a recent trip. It started cutting out when hitting bumps, then finally quit altogether. After dragging it home, hitting the forums, swapping a few parts, following all the sensor tests and wrapping my head around this TBI setup, I am afraid I have a partially dead ECU. -All ignition parts replaced- Ignition Module, Coil, Wires, Cap and Rotor, Plugs. -The truck will crank the engine just fine, but has NO spark at coil or plugs, and NO gas at the injector. The fuel pump comes on with ignition switch for 1-2 sec, there is fuel in the line at the throttle body, I have not checked fuel pressure yet. -A new CPS was installed, I checked the CPS, 217 Ohms (slightly low), 0.54 VAC while cranking the engine. - All other sensors checked out nominal. There is 5 VDC to the TPS and MAP sensors, so the ECU is not entirely fried. -While tracing the sensor wiring, I found a wire broken internally between the CPS sensor and the ECU (red-white wire tied to pin 28), I'm guessing that was the root cause of the failure. I'm afraid the ECU board may have been damaged in the process of the wire failing while driving. -I am looking for information about what I should be seeing for the output signals for the Ignition Module and Fuel Injector from the ECU. I expect they will be low voltage AC pulses, grounding the DC power supplied to the Ignition Module and the Injector. I have not found any specifications for the AC voltage or pulse duration for either the Ignition at pin 27 or Injector at pin 21 of the ECU. I measured both of these signals while cranking the engine, I got ~0.1 VAC at the injector, and basically zero (0.004 VAC) at the ignition module output. These numbers lead me to believe that the output drivers for these functions are damaged or dead, although I can see no signs of physical damage, no burnt smell, melted traces, cracks, or corrosion anywhere in the ecu components. Is there any function programmed in the ECU which would completely shut down the spark- and injector-outputs based on some combination of other inputs for some safety reason ? Any info on the specific layout of components relating to the Ignition and Injector Drivers in the 1987-1990 ECU would be greatly appreciated! And Thank You to all who have gone before me here, the info trail has been invaluable!! -
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 -
Hi! Moses< How are you? Can you give suggestion how to improve the performance of th jeep xj 2.5 if i install bigger tires ,also what are the things needed. Please advice Thank you. Cheers: Mario Bedayo
