JohnMasters Posted August 16, 2011 Share Posted August 16, 2011 Hello Pathfinder friends, My 1992 Automatic Pathfinder has been running good all year until last weekend when the trouble began. I have searched the forum but haven't seen anything with these exact symptoms and was hoping someone may recognize them... -When cold, it is hard to start and will stall if the pedal is not feathered until it warms up(5 or so minutes) -Once warmed up, it idles just fine but totally stumbles/Bucks between 1000rpms and 3000rpms whether parked or being driven -It can be driven but needs to be almost floored to get from 1000 to over 3000rpms. -When in park, if I blip the throttle just a bit I hear some loud popping from the passenger side of the engine bay as if the truck is backfiring but the backfire is not making it to the exhaust and escaping through a small exhaust leak at the exhaust manifold. I was wondering if it was possible for a catalytic converter to get clogged and cause this. SO FAR: -There is NO smoke coming from the exhaust during any of this -The little transmission light switch on the dash is NOT blinking -I checked the MAF wires and cleaned the little MAF electrodes -The EGR valve does not seem to be sticking -There is NO check engine light -The distributor cap and wires looks good and are less than 10 months old -Ive searched for a vacuum leak but have not found one -The Timing belt was changed less than 10,000 miles ago I have not yet checked the computer for any codes but will do so this evening. I'll leave it at that for now and thank everyone in advance for any helpful ideas. :-) Link to comment Share on other sites More sharing options...
adamzan Posted August 16, 2011 Share Posted August 16, 2011 Check the coolant temp sensor, I know it can make the truck run like total crap when it goes bad. It should be near the upper rad hose the one with the yellow connector. The FSM has the specs for it. Also maybe do a fuel pressure test? But first check for codes, its free and couldn't hurt. Link to comment Share on other sites More sharing options...
Tungsten Posted August 16, 2011 Share Posted August 16, 2011 oxygen sensor, replace that Link to comment Share on other sites More sharing options...
sewebster Posted August 16, 2011 Share Posted August 16, 2011 No smoke, from the exhaust, or no exhaust? You can just put your hand over the exhaust pipe and see if anything is coming out. Don't burn yourself... Link to comment Share on other sites More sharing options...
JohnMasters Posted August 16, 2011 Author Share Posted August 16, 2011 NO SMOKE from the exhaust is what I meant. I DO feel the exhaust as I hold my hand over the exhaust pipe. I will check the Temp sensor, pull the codes and deal with the O2 sensor when I get home. Thanks! Link to comment Share on other sites More sharing options...
Alkorahil Posted August 16, 2011 Share Posted August 16, 2011 (edited) Distributor! I will bet if you look the backfire in the engine bay is making smoke come out into the air cleaner box. This will not generate any codes in the ECU either. Edited August 16, 2011 by Alkorahil Link to comment Share on other sites More sharing options...
JohnMasters Posted August 16, 2011 Author Share Posted August 16, 2011 (edited) OK, I just pulled the codes and got a 55 so nothing there. I thought I saw a bit of smoke under the hood while blipping the throttle but it seemed to be coming more from the back of the engine and it was a very small amount. I'll check again. It sure is a strange sounding backfire from under the hood. Is there an easy way to test the distributor? Any possibility that anything is being damaged while I am running the vehicle. Edited August 16, 2011 by JohnMasters Link to comment Share on other sites More sharing options...
Alkorahil Posted August 16, 2011 Share Posted August 16, 2011 Yep yep, code 55 as I thought. Pop the hood and crack open the air box, when it backfires you will be surprised how much smoke there when it is not contained in the box and resonator in the fender. The strange sound is because it is in the intake, not exhaust so it is muffled. Damage? Its not good, could leave alot of carbon build up in the intake, or cause damage to the intake, throttlebody or intake manifild in an extreme case. I have seen this a few times before and had it happen before personally on my truck about 2 summers ago (so I knew exactly what it was when it started) , it is a replace the whole distributor situation. If you can get access, or borrow a known good distributor, it can help you diagnose and double check that this is your problem. Unfortuantely a new distributor on these vehicles is sorta expensive. You might also see in the 'Parts wanted' or 'Parts for sale' sections if anyone on here has a known good used one they might sell you. Link to comment Share on other sites More sharing options...
JohnMasters Posted August 17, 2011 Author Share Posted August 17, 2011 UPDATE, I installed a new fuel filter and started the truck. Same problem continues and it turns out that the smoke that I was seeing yesterday was unrelated as it is a result of a few loose valve cover bolts and oil was dripping down onto the exhaust. Although I was able to recreate the under-hood backfiring there was absolutely NO smoke coming from the air box at all. The back-firing has a metallic sound like something rapping against the inside of the valve cover. I was wondering if it means anything that when I hold my hand over the exhaust, although I feel exhaust, there is NO moisture spitting out with the exhaust. The last time I had a problem and felt moisture coming from the exhaust I was told that it was normal and meant that "something"(I dont remember what)was working correctly. I am still looking for a good distributor! Link to comment Share on other sites More sharing options...
Kingman Posted August 17, 2011 Share Posted August 17, 2011 The moisture coming from the tailpipe sometimes is just condensation - totally normal. Link to comment Share on other sites More sharing options...
sewebster Posted August 18, 2011 Share Posted August 18, 2011 Your metallic sound from the valve cover sounds like something wrong with a lifter or rocker arm. If it's the passenger side it's easy to pop the cover off. You can probably even run it with the cover off. I had a loose rocker arm shaft once (forgot to tighten it properly). Sounded pretty terrible after a while Link to comment Share on other sites More sharing options...
Tungsten Posted August 18, 2011 Share Posted August 18, 2011 That sounds like a possibility too. The rocker arms may have gone bad and the truck can't run right without the right valve lift. Link to comment Share on other sites More sharing options...
JohnMasters Posted August 18, 2011 Author Share Posted August 18, 2011 OK, I'll see if I can get that valve cover taken off this evening. Can anyone tell me what i will be looking for or will it be obvious if there is a problem? Link to comment Share on other sites More sharing options...
JohnMasters Posted August 18, 2011 Author Share Posted August 18, 2011 (edited) OK, I just pulled passenger side valve cover and ran the car for a while and it DOES NOT appear that there is a problem with the lifters or rockers. There is NO sludge at all and everything is a nice gold color which I think is normal. Everything seems to be nice and tight with no real free play to speak of. Watching the rockers is like watching a sewing machine work. It looks totally normal. Too Alkorahil... Did your distributor issues always accompany the smoke from the airbox? I still have yet to see any smoke. Also, I'm not sure if it means anything but the rotor is totally stuck to the distributor. I have removed the screw and tried to remove the rotor when the engine was both hot and cold and IT WONT BUDGE. JUST A REMINDER... When warm, idles fine. then starts to stumble and underhood backfire just above 900rpm. Also, hard starting when cold. This problem was not gradual. It was working fine Friday night and then NOT on Saturday morning. Thanks again for the help so far. This is always much easier with good help! Edited August 19, 2011 by JohnMasters Link to comment Share on other sites More sharing options...
Alkorahil Posted August 19, 2011 Share Posted August 19, 2011 OK, I just pulled passenger side valve cover and ran the car for a while and it DOES NOT appear that there is a problem with the lifters or rockers. There is NO sludge at all and everything is a nice gold color which I think is normal. Everything seems to be nice and tight with no real free play to speak of. Watching the rockers is like watching a sewing machine work. It looks totally normal. Too Alkorahil... Did your distributor issues always accompany the smoke from the airbox? I still have yet to see any smoke. Also, I'm not sure if it means anything but the rotor is totally stuck to the distributor. I have removed the screw and tried to remove the rotor when the engine was both hot and cold and IT WONT BUDGE. JUST A REMINDER... When warm, idles fine. then starts to stumble and underhood backfire just above 900rpm. Also, hard starting when cold. This problem was not gradual. It was working fine Friday night and then NOT on Saturday morning. Thanks again for the help so far. This is always much easier with good help! The distributor problem I am thinking will not be a gradual, it will just go start doing it one day and acting up for no apparent reason or warning. It will seem to idle fine, if you listen close there will be a slight stuble you can barely hear but can feel feel. When you apply the accelerator while parked it will start to stumble more. As to the smoke, no it was not always, I made it do maybe 3 times starting it when it did not want to start when I was diagnosing the problem. These distrubtors use an optic sensor and light inside of them. When rotating inside, whenever the optic pickup sensor passes the light it tells the engine to fire the spark plug for whatever cylinder just passed by in firing order. When the pickup sensor wears out wears out it will 'miss' a pass randomly. Eventually the component will completely fail and not start at all. As a side thought, you might want to get a hold of a timing light and check your ignition timing. It could be that it is just really far out of whack. If you do replace the distributor you will need one anyways. Some auto parts stores will rent them out and they are not too expensive if you want to buy a basic one. (about $40) Link to comment Share on other sites More sharing options...
JohnMasters Posted August 19, 2011 Author Share Posted August 19, 2011 OK, thanks. I do have a timing light and I am about to check that. Also, after doing some research I found several people(on other forums) that seemed to be having the same problem caused by a faulty fuel pump causing a too lean condition thus causing the backfire from the intake. I checked under the hatch that is in the cargo area and although the wires dont look corroded, there sure is a ton of rust in there. Does a faulty fuel pump or sending unit sound like something that may cause this condition. Should I be able to hear the fuel pump working when I first turn the key? I dont feel as though I hear anything at all. I will head to the junk yard in the morning and pick up a distributor or two so I should know if thats the problem by Saturday night. Thanks again for your help! Link to comment Share on other sites More sharing options...
JohnMasters Posted August 22, 2011 Author Share Posted August 22, 2011 (edited) Good morning, I had NO luck at the junk yard as all 5 Pathfinders were already missing there engines so it looks like I'll have to break down and pay retail. I replaced the plugs as they were looking very worn. I Replaced the fuel filter. I adjusted the timing, turning the distro all the way from one direction to the other, the symptoms persist no matter where the timing is set. QUESTION... Are the timing marks on the balancer just painted on or are they notched? At no time did I think I was seeing the marks while I was using the timing light or while the engine was turned off. John M. Edited August 23, 2011 by JohnMasters Link to comment Share on other sites More sharing options...
sewebster Posted August 22, 2011 Share Posted August 22, 2011 The marks on the lower pulley are notched on mine. I believe it is possible to install the pulley on the balancer such that the marks are in the wrong position though. (but I think it's either correct or way off). Link to comment Share on other sites More sharing options...
JohnMasters Posted August 23, 2011 Author Share Posted August 23, 2011 UPDATE... I picked up a new distributor on the way home from work and found what is certainly causing my problem. Although the rotor button was frozen to the distributor shaft and next to impossible to get off, the screw was NOT present and the rotor had twisted just a bit and was a bit cockeyed. After finally getting the rotor off and installing the new one the truck was running noticeably better with NO intake backfiring although the timing was noticeably off as I had messed with the timing yesterday. The problem is that when checking the timing the tick marks are only visible from underneath the truck which had me thinking that the distributor must be installed incorrectly or backwards(is that possible) and that I needed to reinstall it so that I could set the timing correctly, using the marks. It appeared to me that when I had the first tick mark to left aligned with the timing arrow on the engine, TDC, that the rotor was pointing exactly opposite of point #1 So, I pulled the distibutor and used the instructions for installing the distributor that I found from MY1PATH here on the forum, using the first tick mark on the left as TDC but the truck will now not start which had me thinking about the possibility that the pulley with the hash marks was installed incorrectly in the past. So, is it possible to install the distributor backwards and/or install the pulley with the hash marks backwards. If the pulley is backwards will I just be guessing at my timing once I get it started or when the distributor is installed correctly will the tick marks find there way to where they are supposed to be? Link to comment Share on other sites More sharing options...
JohnMasters Posted August 23, 2011 Author Share Posted August 23, 2011 After some homework it would appear that what I was thinking was Compression-TDC was actually Exhaust-TDC and thats why It appeared to me that the distributor was installed backwards so, in my infinite wisdom, I pulled the distributor and actually reinstalled it backwards. Does the crank pulley spin around twice for every once the rotor spins? So, at exhaust TDC the rotor points 180 degrees away from Point #1 and at compression TDC the rotor points at #1 point. Although I believe my current distributor is functional, when spinning the shaft it sounds and feels like SAND has been used to lubricate the shaft so I am thinking that I should go ahead and keep and install the new one. If, in fact, the tick marks on the crank pulley are OFF in some way, is there another way to MAKE SURE your timing is set correctly other than FEEL. Link to comment Share on other sites More sharing options...
sewebster Posted August 23, 2011 Share Posted August 23, 2011 I think the pulley can be put on wrong unfortunately. You can pull your upper timing cover and passenger rocker cover to figure things out for sure.... Link to comment Share on other sites More sharing options...
adamzan Posted August 23, 2011 Share Posted August 23, 2011 The pulley itself is keyed to the crankshaft and (at least mine) can only go on one way. It is when people undo the 6 bolts that hold the 2 parts of it together is when this can happen. Link to comment Share on other sites More sharing options...
JohnMasters Posted August 23, 2011 Author Share Posted August 23, 2011 (edited) I bought this truck about a year ago from the first owner and based on the receipts in the glovebox the timing belt was replaced around 5000 miles ago so I guess It could have happened then. Is it possible to get the car started if the distributor is installed a tooth or two off thus throwing the timing marks way off or will it only start if the distributor is installed spot on? Heck, I just looked at my join date and apparently I have been driving the pathfinder for almost TWO years! Yahhhh!!! Edited August 23, 2011 by JohnMasters Link to comment Share on other sites More sharing options...
sewebster Posted August 23, 2011 Share Posted August 23, 2011 It will probably start if you are a tooth off. Not sure about two. "Bad things" can happen if you try to start it for any length of time in the wrong position (like 180 deg out or something). Link to comment Share on other sites More sharing options...
JohnMasters Posted August 24, 2011 Author Share Posted August 24, 2011 OK, I got lucky. Although I had to install the distributor a few times before getting it correct, it now fires up on the first turn. The reason I had some trouble with the procedure is because the timing marks are obviously out of whack so when I had the marks set to what should be TDC, installing the distro with the rotor facing #1 was not working. I removed the #1 plug to see the piston no where near the top so using a long wooden dowel in the the plug hole I cranked the engine over(By hand) until the dowel was all the way up, which left the timing marks no where near the timing marker, installed the distro and Voila! Now my only issue left is getting the timing set correctly without the use of the timing marks. Thanks for your helpful responses and to SUM THIS THREAD UP... THIS ISSUE WAS CAUSED BY A ROTOR BUTTON WHICH, ALTHOUGH SEIZED TO THE DISTRIBUTOR SHAFT, WAS MISSING ITS INSTALL SCREW AND HAD SPUN JUST ENOUGH ON THE SHAFT TO CAUSE THIS CONDITION. Thanks again NPORA!!!!!!!!!!!!!!!!!!!!!!!!! Link to comment Share on other sites More sharing options...
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