Jeff Clyde Posted November 1, 2009 Share Posted November 1, 2009 Misses on 4,5, & 6 constantly. Truck has had complete tune up, coil. Fuel pressure ok, has pulse at the injectors, spark, have tried a good pcm, compression is even across the board ( 125- 130 ) IIRC, exhaust has been dropped, new syncro. All this has been done at another dealer in the past month. It is now been dropped on my doorstep. Truck has 250,000 km on it, and I have rechecked all previous repairs and re- verified all readings and tests. Any help would be appreciated. Thanks Quote Link to comment Share on other sites More sharing options...
Aaron Posted November 1, 2009 Share Posted November 1, 2009 Plugs wet with fuel? Quote Link to comment Share on other sites More sharing options...
Jeff Clyde Posted November 1, 2009 Author Share Posted November 1, 2009 Aaron, no they are dry, I was thinking timing off but it is only the LH bank that is dead. It is at another shop I help out at periodically, so when I go there I only have limited time and tooling to use. Quote Link to comment Share on other sites More sharing options...
LARRY BRUDZYNSKI Posted November 1, 2009 Share Posted November 1, 2009 Chafed harness, bad ground???? This sounds like a wiring issue. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted November 2, 2009 Share Posted November 2, 2009 My best advice... start at the very beginning... pretend that nobody has ever looked at this concern... Disregard everything that the other dealer has done. Failing to do this can and will trap you... honest - DAMHIKT!!!! I'm not sure what this has for a harmonic balancer... if it's like the one on the 4.0, stick your finger inside and check to be sure the damper isn't floating around loose... What are your fuel trims? Is a vacuum gauge tied into the intake manifold steady? What do the injectors sound like with a stethoscope (this is reaching kinda far... you need to concentrate on things that will affect only one bank). Quote Link to comment Share on other sites More sharing options...
Mekanik Posted November 2, 2009 Share Posted November 2, 2009 I agree with everything that has been said. Are you sure that those are the cylinders that are misfiring and not just what the power balance tells you? I saw a vehicle once where the CMP was not installed properly, and the power balance was showing cylinder #4 misfiring, but it was actually a cylinder on the other side of the engine that was misfiring. Is this a steady misfire or does it come and go? Manual compression test? Quote Link to comment Share on other sites More sharing options...
mchan68 Posted November 2, 2009 Share Posted November 2, 2009 I agree with everything that has been said. Are you sure that those are the cylinders that are misfiring and not just what the power balance tells you? I saw a vehicle once where the CMP was not installed properly, and the power balance was showing cylinder #4 misfiring, but it was actually a cylinder on the other side of the engine that was misfiring. Is this a steady misfire or does it come and go? Manual compression test? Given the fact that the thread title is that of a 3.0L Ranger, I WAS going to post something I came across awhile back. Although unrelated, I happened upon an E-Series V10 issue. Ever since the engine was re-assembled, it was running like crap. It took a week and a half of "playing around" by other guys in the shop going nowhere. I will never forget the WDS (yes I said WDS) power blance screen. It was a PERFECT "zig-zag". When I came into the picture, was when I suggested the possibility of the engine being mis-timed. At that point, the SM was open to any suggestion, so he let ME open it up. Low and behold, the driver side bank was off exactly one and a half tooth. I couldn't believe this thing actually ran, without doing any damage to the valves!!! That was one situation I never forgot. But since this particular engine is an overhead valve type setup, I guess it's a moot point anyways, isn't it? Quote Link to comment Share on other sites More sharing options...
Mekanik Posted November 2, 2009 Share Posted November 2, 2009 Originally Posted By: Mekanik I agree with everything that has been said. Are you sure that those are the cylinders that are misfiring and not just what the power balance tells you? I saw a vehicle once where the CMP was not installed properly, and the power balance was showing cylinder #4 misfiring, but it was actually a cylinder on the other side of the engine that was misfiring. Is this a steady misfire or does it come and go? Manual compression test? Given the fact that the thread title is that of a 3.0L Ranger, I WAS going to post something I came across awhile back. Although unrelated, I happened upon an E-Series V10 issue. Ever since the engine was re-assembled, it was running like crap. It took a week and a half of "playing around" by other guys in the shop going nowhere. I will never forget the WDS (yes I said WDS) power blance screen. It was a PERFECT "zig-zag". When I came into the picture, was when I suggested the possibility of the engine being mis-timed. At that point, the SM was open to any suggestion, so he let ME open it up. Low and behold, the driver side bank was off exactly one and a half tooth. I couldn't believe this thing actually ran, without doing any damage to the valves!!! That was one situation I never forgot. But since this particular engine is an overhead valve type setup, I guess it's a moot point anyways, isn't it? I was thinking the exact same thing, because I was thinking of a 4.0l SOHC. Quote Link to comment Share on other sites More sharing options...
GregKneupper Posted November 2, 2009 Share Posted November 2, 2009 I have seen 02 sensors cause misfires on complete banks. Also make sure that the correct injectors are installed on that bank also. I had another one at one time where someone had replaced 1 injector with the wrong injector and it caused the entire bank to miss as well due to it overfueling so much. Quote Link to comment Share on other sites More sharing options...
Jeff Clyde Posted November 3, 2009 Author Share Posted November 3, 2009 I get to "visit" with this truck again Wed night, and am going to check some wiring first from a splice to the left bank injectors, then I am going to start from scratch with my own steps and results. Thanks Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted November 4, 2009 Share Posted November 4, 2009 Do your self a favor and check the cam sensor for correct orientation before you do anything else. If this is off the PCM will start firing the SEFI injectors at the wrong time and havoc ensues. Follow the shop manual and set the engine at top dead center for number 1 cylinder and see if the alignment tool will slips on the synchro, if not reset and recheck, if its dead on then I am out of ideas. Just make sure you get your time covered! Quote Link to comment Share on other sites More sharing options...
ktmlew Posted November 4, 2009 Share Posted November 4, 2009 Had a 3.0L Ranger that had a salavge yard engine installed. Ran dead rich at part throttle but all scanner info said the PCM was maxed-out trying to lean it out. Fuel pressure & regulator OK, exhaust not plugged...turns out it was a Flex Fuel vehicle which uses diferent injectors. Guy finally came up with correct injectors and all was perfect again. If yours has a constant misfire on one bank, with spaark, it has to be fuel delivery issues. Either the PCM has gone whacky, but that usually fuel fouls plugs, or as mentioned previously something has gone awry with cam senor signal? Quote Link to comment Share on other sites More sharing options...
gasgasman Posted November 17, 2009 Share Posted November 17, 2009 You have a cat convertor coming apart on the passenger side. The PCM sees a rich condition and is leaning the fuel out to compensate. Drop the exhaust down at the manifolds and see if it still misses. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted November 17, 2009 Share Posted November 17, 2009 Generally speaking.... if you have a plugged cat you will see one LTFT go way rich and the other LTFT go way lean.... Important to remember... the PCM cannot see "rich". It can see copious amounts of O2 or very little O2 or anywhere in between... If it sees little O2... it "thinks" rich. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.