Gyropath Posted November 16, 2016 Share Posted November 16, 2016 I'm almost ready to give up on my 92 Pathfinder SE. 3.0 auto. with 230k. Long story (2yrs part time). Boys take it on a trip, cat gets red hot, determine plug wires causing spark jumps. They replace plugs, wires, remove cat, replace with pipe and muffler. It's running decent, so they drive back to home (350 miles) and almost make it before it starts losing power and it finally stalls. They pull it to auto parts store and advise me it has no spark. I go out to fix it, replace ignition module, coil, rotor, and cap. No change. Haul it home and park it. Do a bit of research, determine crank angle sensor may be issue-replace it. Truck now fires and idles rough, stalls if you press and gas, and won't start at all after few tries. Leave it sit a day, and it repeats cycle. Longer it sits alone, the longer it will idle the next time I start it, unless I try feed it gas. Fuel pump does make noise so I think ok, replace fuel filter-no change. Ok so next I replace fuel pressure regulator-no change. The longer it sits (overnight minimum) the longer it will start and idle, but only idle!! I also recollect that the gas tank seemed to build up what seemed to be excessive vacuum previous to this chain. Anybody have any insight into what I'm dealing with here?? Almost ready to accept defeat. Almost. Link to comment Share on other sites More sharing options...
adamzan Posted November 16, 2016 Share Posted November 16, 2016 Could be a bad distributor. It will usually run well cold until the bearings warm up. Link to comment Share on other sites More sharing options...
Gyropath Posted November 16, 2016 Author Share Posted November 16, 2016 The truck just runs for awhile-not well, and immediately stalls/sputters if you push on the gas. It seems as though it doesn't have time to warm up. Is there a way to determine health of the distributor? Link to comment Share on other sites More sharing options...
k9sar Posted November 18, 2016 Share Posted November 18, 2016 check/wiggle the connector on top of your MAF. Always an easy check for something that can seriously F*k with your ability to run Link to comment Share on other sites More sharing options...
Gyropath Posted November 18, 2016 Author Share Posted November 18, 2016 Tried wiggling the connector a bit-didn't seem to affect it. Beginning to think maybe the original problem has possibly been "cured" and I have a different problem now-old gas. If I hook up the booster and really crank it over for awhile it does the "almost running on its own" deal like a very flooded engine, but won't quite reach the self-running mode. The original failure happened about 2+ yrs ago. Think I will drain the tank and put fresh fuel in it. Any other ideas out there? 1 Link to comment Share on other sites More sharing options...
adamzan Posted November 18, 2016 Share Posted November 18, 2016 The truck just runs for awhile-not well, and immediately stalls/sputters if you push on the gas. It seems as though it doesn't have time to warm up. Is there a way to determine health of the distributor? Take off the cap/rotor and the cover under that and see if there is any brown dust. Or if you can source a used one for cheap, try swapping it. Also, check all sensors especially the coolant temp sensor, if it thinks the truck is in the arctic it will flood it with fuel. Tried wiggling the connector a bit-didn't seem to affect it. Beginning to think maybe the original problem has possibly been "cured" and I have a different problem now-old gas. If I hook up the booster and really crank it over for awhile it does the "almost running on its own" deal like a very flooded engine, but won't quite reach the self-running mode. The original failure happened about 2+ yrs ago. Think I will drain the tank and put fresh fuel in it. Any other ideas out there? Possibly, but I doubt it. Mine ran fine on 2 year old fuel, yes it isn't a good idea but I didn't have time to drain it properly. Couldn't hurt to put fresh gas in though. Link to comment Share on other sites More sharing options...
Gyropath Posted November 18, 2016 Author Share Posted November 18, 2016 Inner area of distributor is clean, but I replaced cap, rotor, crank angle sensor, awhile back in the diagnostic process. Purchased a used distributor on EBay now so I'll try that when it gets here. Found an earlier discussion about a truck with similar issues that resulted in "distributor " cure, but not sure if that meant he replaced it. Likewise, I have not experienced gas "too old to burn" in a vehicle before, but this time I have begun to wonder. Link to comment Share on other sites More sharing options...
Slartibartfast Posted November 19, 2016 Share Posted November 19, 2016 If you want to check your gas for water or see how the inside of the tank is doing, the pump's under an access cover under the cargo area carpet, so you don't have to drop the tank to take a look. I would be very surprised if two-year old gas was the problem, though. And vacuum in the tank, you mean that hiss when you open the cap? Both of mine have done that whether they had an issue or not--I think it's just how the evap system works. The bad dizzy on these usually crops up as the engine warms up (from what I've read, anyway, haven't had a problem with mine yet). Runs fine, warms up, then has issues. Sounds like yours won't do anything but idle, if that, then conks out entirely once warm, so I'm not sure the dizzy is what's wrong. In the first post, you mention the catalyst getting hot enough to glow, possibly due to a misfire. That makes me wonder if the cat might have overheated enough to melt the catalyst honeycomb stuff and clog up. This makes sense with it's stalling out when you give it gas, but running--somewhat--at idle. The PO of mine had a guy drill a hole in the exhaust and stick a camera in there to check that the cat was good. If the dizzy doesn't fix the problem, you might try something similar.Funny story, actually, the PO of mine had the cat checked, injectors cleaned, all kinds of stuff to try and chase down the lack of power, and nobody thought to check the airbox. Turns out there was a rat's nest in there.And a rat. Hopefully the issue with yours ends up being as simple to fix, but better smelling. Oh, one last thing. Any ECU codes? Link to comment Share on other sites More sharing options...
adamzan Posted November 19, 2016 Share Posted November 19, 2016 He said in the first post they removed the cat. Link to comment Share on other sites More sharing options...
Gyropath Posted November 19, 2016 Author Share Posted November 19, 2016 Ya the cat is gone and no rat in the air box. I also removed the muffler at one point to see if that had plugged. There may have been a code referring to the crank angle sensor if I remember correctly, that led me to replace it. This is great to hear from you guys that know these trucks-seems like local dealer mechanics are clueless discussing older rigs. Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted November 19, 2016 Share Posted November 19, 2016 You still don't have any new stored codes? Have you tried testing the TPS or unplugging the oxygen sensor wire? Link to comment Share on other sites More sharing options...
Gyropath Posted November 19, 2016 Author Share Posted November 19, 2016 I will check for codes again for current status, and unplug the osw. How would I test for TPS malfunction? Link to comment Share on other sites More sharing options...
Cuong Nguyen Posted November 19, 2016 Share Posted November 19, 2016 1 Link to comment Share on other sites More sharing options...
Gyropath Posted November 19, 2016 Author Share Posted November 19, 2016 Wow! Thank you! Was doing some research also, and with your post I will check it out tomorrow. Link to comment Share on other sites More sharing options...
Slartibartfast Posted November 19, 2016 Share Posted November 19, 2016 Sorry I missed that! Rules that out then. Link to comment Share on other sites More sharing options...
adamzan Posted November 19, 2016 Share Posted November 19, 2016 Ya the cat is gone and no rat in the air box. I also removed the muffler at one point to see if that had plugged. There may have been a code referring to the crank angle sensor if I remember correctly, that led me to replace it. This is great to hear from you guys that know these trucks-seems like local dealer mechanics are clueless discussing older rigs. Most newer mechanics won't be able to figure out these trucks, since they are only obd1. Not to fault them but they are just simply not used to it. 99% of the time these issues are sensor related, or more rarely, the distributor. The cat would have gotten hot due to a rich running condition or a misfire that went unnoticed. They are 20+ years old, so the sensors are getting tired, wiring gets brittle, corroded, etc. Cleaning up the grounds, and other connections helps. The MAF wiring at the connector is known to cause issues but if moving it doesn't cause it to change then it is probably fine. Link to comment Share on other sites More sharing options...
Gyropath Posted November 19, 2016 Author Share Posted November 19, 2016 Having owned many various "project" American trucks and cars over the years, this will be the first truck that I have considered replacing the distributor in. It seems a logical path here, as the water pump had blown out earlier and so the timing belt etc were replaced. Old electrical systems are always a pain to deal with, but I have noticed some of these connectors are unique. A side note: winter arrived yesterday afternoon in Minnesota! Heat required in shop from here on! Link to comment Share on other sites More sharing options...
Gyropath Posted November 19, 2016 Author Share Posted November 19, 2016 You still don't have any new stored codes? Have you tried testing the TPS or unplugging the oxygen sensor wire? There are no stored codes, which may be due to replacing battery earlier, and the truck hasn't run long enough since. The TPS seems ok- started at .36 went to 3.94 and as I accelerated and returned back to start. O2 wire made no difference. Link to comment Share on other sites More sharing options...
adamzan Posted November 20, 2016 Share Posted November 20, 2016 Try unplugging the coolant temp sensor and firing it up. It's the yellow connector, to the left of the distributor. Link to comment Share on other sites More sharing options...
Gyropath Posted November 20, 2016 Author Share Posted November 20, 2016 Just curious: would any of the sensors affect the idle / acceleration if it won't run long enough to actually change engine operating temperature? Link to comment Share on other sites More sharing options...
Slartibartfast Posted November 20, 2016 Share Posted November 20, 2016 Yes. Whatever the temperature, the ECU needs to know the speed and position of the camshaft (using the position sensor in the distributor) so it knows when to apply fuel and spark. It needs the MAF to tell it how much air is going in and the temp sensor to tell it the motor's temperature so it knows how much fuel to inject. If the ECU can tell the MAF or temp sensor isn't working, it guesses at what the values probably should be well enough to limp you home. The computer's not great at knowing when a sensor is shot, though. If the MAF or temp sensor is malfunctioning, but the ECU doesn't know it, your fuel mix gets thrown off. A common test on the MAF is to unplug it and see if the engine runs better on guesswork; if it does, there's something wrong with the sensor. I would try the same test on the coolant temp sensor. Re-reading your symptoms (more closely this time!) it kinda sounds like it's flooding out, and I've heard of these doing that when the temp sensor or temp sensor connections are shot. Link to comment Share on other sites More sharing options...
Gyropath Posted November 20, 2016 Author Share Posted November 20, 2016 Interesting information! My thought process understood how the MAF, TPS, and crank position sensors would affect the immediate start up idle and could cause it to choke and die quickly, but hadn't thought the Temp or O2 sensors would have any affect unless the engine actually started warming. I think the record idling period has been maybe 3 minutes max at this point, until it starts to sputter and die. Will hafta try er without the temp sensor connected soon. Link to comment Share on other sites More sharing options...
gutbusterman Posted November 22, 2016 Share Posted November 22, 2016 Hello fellow Minnesotan! Another thought for the fuel issue: try pulling the fuel pump relay, and putting some unburned propane into the intake. A vehicle will run for a few seconds on propane. If it starts and runs good for a second or two, it's your gas. I didn't see on this post if the fuel pressure was checked. Low fuel pressure will cause a lean condition and cause you problems. Im not sure the spec, but I would guess 45 psi on the fuel pressure. I bet some of the other folks here know the pressure spec. Good luck. Link to comment Share on other sites More sharing options...
Gyropath Posted November 22, 2016 Author Share Posted November 22, 2016 Good to hear from a local! Although I haven't tested the pressure, I don't think it's a problem-the truck will run for awhile, and actually seems to flood. Got the replacement distributor today and after I try the temp sensor test, will do the swap. Soon as time permits! Link to comment Share on other sites More sharing options...
PathyAndTheJets Posted November 22, 2016 Share Posted November 22, 2016 Mankato checking in! Might try picking up a noid light set to be sure the injectors are pulsing correctly, as well. Handy tool to have anyway. Link to comment Share on other sites More sharing options...
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