JT4x4
The Mud Pit => Wrenching => Topic started by: zjorvis97 on June 15, 2010, 04:04:44 AM
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http://www.facebook.com/profile.php?id=594533289
If the about didn't work here is another link to the video on photobucket
http://s599.photobucket.com/albums/tt76/bluesail25/?action=view¤t=P1020127.mp4
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The engine is Dieselling. Somehow the engine is getting fuel and the heat of the engine and the compression is enough to set of the reaction. I don't know why it does it but I have seen it before.
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I used to have an old carbureted Mustang that did that every now and then, but it didn't go as long as yours does. If you google engine dieseling you might find some ideas for what is causing yours.
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i thought the term was rolling idle, dieseling is when it won't shut off?
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I thought the video was of what your engine was doing after you turned the ignition off. I didn't realize that's the way it's currently idling. Could it be something in your timing? I was going to say it's a vacuum leak from the sound in the video, but then I noticed you have the top taken off so that explained the sucking air sound. I've honestly never had a vehicle do that so I wouldn't even know where to start.
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the timing is jacked all it is doing is burning off the vapors left i have never seen it in a fuel injected motor before though cause the spark gets killed when you shut off the key
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The timing is set by the computer and can't be manually adjusted. I have tested, replaced and checked every sensor. I managed to find someone who knows the 5.2 motors well and he said check the grounding straps for the engine and computer. So we will see today brings.
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try seafoam.. i know it sounds like a quick fix, but it may help. sounds more like a lack of fuel, not extra fuel. when was the last time you cleaned the fuel system?
dieseling is igniting fuel without spark by using engine compression. To see if the plugs are firing correctly, pull one off, start it and watch to see if it sparks. remember,1. don't hold it with bare wet hands and 2. the plug needs to be grounded to spark. if all the plugs works fine it is a fuel issue. it doesn't seem like timing to me being as computers either work, or don't work. don't let it run too long w/out the plug in though, just enough to get a spark.
hope it helps
-reg
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I bought a fuel pressue gauge today and that is my next step. The jeep has 165,000 miles and to my knowledge the filter has not been changed. It has sat for the 3 or 4 months so i am guessing this is an issue. I will post up how things go.
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the fuel pressure was normal, 40-45psi. firing order was right.
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Are all of your plugs and wires good? Maybe a cylinder missfire, or timing issue? I had a cylinder down once on my 1.8 turbo jetta, and it ran awful and sounded like an angry lawnmower.
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Nope, all the plugs and wires, even ignition coil are brand new. I ordered a lap top based computer diagnosic and tuning tool last night. I guess once i can get in there i will either find it or not. I am hoping the timing chain didn't jump a tooth, which i am not sure how is would since i only ever had it idle and rev to 2500-3000 rpm with no load on it.
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Could a bad distributor make an engine run like this?
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Nope, all the plugs and wires, even ignition coil are brand new. I ordered a lap top based computer diagnosic and tuning tool last night. I guess once i can get in there i will either find it or not. I am hoping the timing chain didn't jump a tooth, which i am not sure how is would since i only ever had it idle and rev to 2500-3000 rpm with no load on it.
did you replace the cap and rotor how does it run under load
Could a bad distributor make an engine run like this?
do you have timming marks on the front of the block on the ballencer check the timing
if you can get the computer diagnostic program to run a live scan you can check the timing that way it should be about 8-14* btc i can't find the info to be for sure though
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I've got the obd 2 software that reads in realtime
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I have the live data scan as well. I got a new cam sensor. We will see what happens today.
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So new crank sensor, cam sensor, cap, rotor, wires, check timing and it was fine. TPS sensor and MAF sensors read correct numbers on the live scan tool. Anyone have any ideas. I am doing a compression test tomorrow.
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Partially plugged catalytic converter.
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there is no cat on my jeep, just muffler
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ECU?
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if it was a bad ECU, I would think the engine wouldn't run at all. I am going to try and replace the distributor.
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if it was a bad ECU, I would think the engine wouldn't run at all. I am going to try and replace the distributor.
Not True, My camero had a bad ECU, and it still ran. Just the speedometer, AC, and fuel control (would step on gas, but no more fuel added till throttle was wide open, made for some interesting driving) were affected. Was very confusing till I had a shop check it out (was a 91, so no OBD II)