jimb Posted July 25, 2014 Share Posted July 25, 2014 Just found the site, lots of good stuff. Can't find anything similar via search, so I'd appreciate some help. My '95 V6 has run well till this summer, it has 190k on it. It runs fine until it gets warm, then won't accelerate, misses and bucks. When the weather is cooler it takes longer to get to this point. The only code is 55. I tested the coil and resistance was off, but new one didn't help. I've looked for vacuum leaks, and found a couple small hoses were broken, and the hose was off of the fuel pressure reg. behind the intake. No help. It seems to me that it isn't getting fuel, and the problems comes on gradually (like a minute or 2 from a slight miss to undrivable). But it will still idle and run with light throttle pressure. I have cleaned the fuel filter. I haven't checked the fuel pressure. It has also become harder to start, have to use the throttle some to start. (which came on suddenly, it before started quickly in any weather). I like this car, it's the best winter car I've had, and does well off road. Any help would be appreciated. Jim 1 Link to comment Share on other sites More sharing options...
adamzan Posted July 25, 2014 Share Posted July 25, 2014 Unplug the o2 sensor and see if it runs better. Make sure you unplug it while the truck is off though. Its on the tree of connectors on the passenger side. Link to comment Share on other sites More sharing options...
jimb Posted July 25, 2014 Author Share Posted July 25, 2014 Thanks. Is there a way to tell which it is? I can't from the drawing in the manual. Link to comment Share on other sites More sharing options...
Kingman Posted July 25, 2014 Share Posted July 25, 2014 If that doesn't do anything, test the ECM Coolant Temp Sensor per the FSM in the garage section and see how that's doing. They can fail along with the O2 sensor without the ECU throwing a code. Link to comment Share on other sites More sharing options...
jimb Posted July 25, 2014 Author Share Posted July 25, 2014 I haven't unplugged the O2 sensor yet, but the coolant temp sensor readings are: Cold: spec,is 2.1 to 2.9 ohms, reading is 2.99 Hot: spec.is 0.30 to 0.33, reading is 0.4 Makes sense to me that the greater resistance on the hot end could cause the problem. I'll also try unplugging the 02 sensor as soon as I figger out which it is. Thanks. Link to comment Share on other sites More sharing options...
Revco Posted July 25, 2014 Share Posted July 25, 2014 I just did both O2 and coolant temp sensor. If I remember right, it's the larger of all the harnesses on the passenger side...kind of oval like connector...and goes back past the firewall. I think it had three wires, black/white/white...but I'm not looking at mine, so could be wrong. You can follow it up from the intermediate pipe if you have trouble. Just an FYI, I was having O2 codes that were keeping my ECU from throwing a code for the Engine Coolant Temp Sensor, but the sensor "tested" fine. Both needed replacement on my 260K mile Pathy and that O2 sensor's on a recommended 60K mile replacement cycle, just so you know. Temp sensor's only $35 from your local dealership, even cheaper from Courtesy...easy to replace on a 95...it's right past your upper radiator hose on the intake. You will probably have to remove both the sensors to replace the engine temp sensor...the first is the gauge sensor (one wire), the second is your ECU coolant sensor (two wire). You're pretty close to a 100K tune up cycle...might also be wise to check your plugs...or maybe just replace your plugs, wires, cap and rotor. Pretty easy job except for #6, hate that thing. If you haven't owned it since 100K...no telling what was or wasn't done on it. Link to comment Share on other sites More sharing options...
Precise1 Posted July 25, 2014 Share Posted July 25, 2014 It couldn't hurt to change it, that is out of spec more than 2x the entire range and they aren't very expensive. I haven't checked the fuel pressure. It has also become harder to start, have to use the throttle some to start. (which came on suddenly, it before started quickly in any weather). This does sound like fuel pressure as you shouldnt have to touch the gas. Try leaving the ignition on for 5-10 seconds before you crank it to see if it builds more pressure, otherwise you might want to check the output of the throttle position sensor, and then perhaps the fuel pressure. I always recommend one step at a time though so you have direct corolation of any changes (good or bad) to one specific thing. Thanks. Is there a way to tell which it is? I can't from the drawing in the manual. It is one of the 4 or 6 on the tree right behind the fuel filter on the passenger fender. The wire is routed straight down and back, then crosses over the tranny. The best way to find it is to have someone underneath pulling jiggling the wire that you traced from the sensor, and someone watching to what moves from the engine compartment. Then label it... B Link to comment Share on other sites More sharing options...
jimb Posted July 25, 2014 Author Share Posted July 25, 2014 I thought that unplugging the o2 sensor might help, but it's not so hot today and took awhile to get hot enough. Sure enough finally started to buck. I am hopeful that installing a new engine temp sensor will help. The problem is temperature related so makes sense to me. But I've been wrong several times..........I have tried letting the fuel pump build pressure, no difference. .I am having trouble understanding the fuel pressure reg. but I'll look at the FSM. Thanks for the help. Link to comment Share on other sites More sharing options...
Mr_Reverse Posted July 27, 2014 Share Posted July 27, 2014 Sounds to me like the fuel pump is starting to fail. I would try driving with a fuel pressure gauge hooked up so you can see it while driving. If the pressure starts dropping when the engine acts up then odds are a failing pump. Another possibility is the crank sensor is failing and when it gets hot enough it quits reading correctly. It is built into the distributor and it is possible that you just got a bad one. Link to comment Share on other sites More sharing options...
Jnnydeppluver Posted July 28, 2014 Share Posted July 28, 2014 I'm having the same exact problem with my 95 pathfinder, if you figure out what it is can you please post on here!! Thanks Link to comment Share on other sites More sharing options...
jimb Posted July 28, 2014 Author Share Posted July 28, 2014 I sure will. I'm going to try the sensor first, then the fuel pressure. It is a somewhat daunting process. When I first worked on cars, you'd check the igntition points, cap and wires, timing, and float level in the carb. Now it's 100's of feet of hoses and wiring, sensors, and magic boxes. But I'll get it. Link to comment Share on other sites More sharing options...
Jnnydeppluver Posted July 30, 2014 Share Posted July 30, 2014 I know exactly what you mean, we have already replaced parts, but still nothing. It's a headache, especially since its our only vehicle! Link to comment Share on other sites More sharing options...
jimb Posted August 4, 2014 Author Share Posted August 4, 2014 I have made progress, at least as to being able to drive the car. I determined that the fuel pump was OK. I read that the vehicle would run in failsafe mode, so I could at least could get to the parts store. I tried to put in into failsafe. I tested the connection to the distributor for the cam position sensor, then clipped the ground wire. It ran fine after that, in even very hot outside temps. I'm not sure if it is in failsafe mode, or just disabling the sensor has made the difference. It runs fine, is NOT limited in rpm's, the only thing that is different is shifting. It will occasionaly stay in 2nd gear way too long, but the trans. has been going bad for months. I understand from this forum that the entire dist. must be replaced in order to replace the sensor. It does have screws that can't be removed. I'll replace it when I can. Jnnydeppluver, it you want to try this (at your own risk), find the connector in the harness leading to the distributor. The connector is right on the front of the engine. Unplug it and clip the black wire on the LEFT (passenger) side of the connector. (you should probly check with your ohmmeter to make sure the black IS the ground wire. Check continuity between that black wire and the engine block) Cut so there enough wire to solder it back together. The wires change color (?) at the connector for some reason, just look at the feed side (left). Make sure the key is off. I can't guarantee anything, but it has temporarily worked for me. It should be fixed properly for emissions sake, I suppose. Good luck. Jim Link to comment Share on other sites More sharing options...
Jnnydeppluver Posted August 7, 2014 Share Posted August 7, 2014 We tried what you suggested but it still didnt work this thing is such a headache. I just don't know what to do and don't have the money to take it to a shop or trade it in. And autozone told us that it was to old for them to check and see what code it was tripping. I'm so lost. Link to comment Share on other sites More sharing options...
jimb Posted August 7, 2014 Author Share Posted August 7, 2014 If you haven't already, checking the codes is not hard, but you have to remove the passenger seat. It's easier than it looks. Good luck! PS, my Pathfinder has not lost power since the "modification", nor are the rpm's limited, so I guess it is not in failsafe. but the problem has been isolated... I guess... I drove it to my cabin (camp trailer) in the mountains yesterday, no sweat. (except that a bear had broken in and trashed the inside, and tore open all the canned food). Link to comment Share on other sites More sharing options...
Jnnydeppluver Posted August 7, 2014 Share Posted August 7, 2014 Oh goodness! But it's getting to where its harder to crank and whatever is wrong with caused the starter to go out and we had to replace it. When we drive it we have to put it into nuetral when we stop so it won't die. Other wise it will just idle for a second and die. And just recently if we are sitting to long it tries to overheat but as long as its moving it won't. But it doesn't want accelerate and sometimes the rpms just bounce around and it bucks likes its running out of gas unless we are going 70 on the interstate then it smooths out. Anything below 65 it starts bucking again. We have replaced the fuel filter, o2 sensor, map sensor distibutor and roter button and spark plugs and wires and some other sensor that I can't name at the moment and the starter as well. We have checked the fuses also. Oh one more thing there is a rattling sound coming from under the hood as well while we are driving and my husband says he thinks it might be the valves loose but isn't sure cause he knows very little about cars lol. This whole thing has been a nightmare and its still going! Link to comment Share on other sites More sharing options...
jimb Posted August 7, 2014 Author Share Posted August 7, 2014 Have you checked the ignition timing? Sounds like the overheating, rattling, and hard cranking could be timing is too far advanced. I would check this, won't cost much if he can't do it himself. It's a basic tuneup procedure. Link to comment Share on other sites More sharing options...
Jnnydeppluver Posted August 7, 2014 Share Posted August 7, 2014 How would we check that? It's not the timing belt is it? Because I know those can cost a pretty penny to put it if a car jumps time. Link to comment Share on other sites More sharing options...
Jnnydeppluver Posted August 7, 2014 Share Posted August 7, 2014 To put it on** Link to comment Share on other sites More sharing options...
jimb Posted August 8, 2014 Author Share Posted August 8, 2014 You need a timing light. And follow the instructions in the manual. Or just pay someone to do it. Or could be the timing belt. I don't know. But I'd would check the distributor timing first. A basic tuneup operation. Let us know. Link to comment Share on other sites More sharing options...
Jnnydeppluver Posted August 8, 2014 Share Posted August 8, 2014 Okay thanks, and will do. Link to comment Share on other sites More sharing options...
Jnnydeppluver Posted September 8, 2014 Share Posted September 8, 2014 We finally figured out what was wrong, the distributor is stripped, the rotor button is moving and not supposed to, thank goodness we finally figured it out. All we have I do is replace the distributor and it will work fine, till then we have to move the rotor button back into place and it will work fine till it moves again. Link to comment Share on other sites More sharing options...
SpecialWarr Posted September 11, 2014 Share Posted September 11, 2014 You may be able to epoxy that into place if you need to, one of my friends did that with his Volvo. His temporary repair lasted four years and 70,00miles!! Link to comment Share on other sites More sharing options...
Jnnydeppluver Posted September 12, 2014 Share Posted September 12, 2014 Huh, thanks we might have to try that! I'm just glad we finally figured out what it was, we spent a lot on other parts already trying to figure it out!! Link to comment Share on other sites More sharing options...
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