Superkirby Posted July 29, 2013 Share Posted July 29, 2013 Ok, hope you all can help... I have a 1995 Pathfinder v6/auto with 125k miles. When I got it, it ran a little rough and the guy said he thought it was the EGR valve. Not a problem. Read about pulling codes from the ECM and yep, code 32 - EGR function. Replaced the EGR and it was a little better but not really. Checked the codes again and it got (and still have) code 51 - Injector circuit. Read somewhere to let it idle and pull the injector leads one at a time until you disconnect an injector and it doesn't change the way it runs. I can reach 4 of them, the other 2 appear that I would have to remove the intake manifold to get at. The 4th one I disconnected didn't really change the way it ran as compared to the other 3. Not sure the way the cylinders are numbered, but it's the front injector for the drivers side. I ran some B12 through a tank of gas and for 100 or so miles it got better. A couple tanks later I put some Seafoam in just to see if anything would happen. Again, it got better for a little while. Now it's intermittent. Sometimes it runs great - smooth, sounds good, has noticeably more power, etc. Then while driving you can feel it kick out and the whole thing runs like poo again. A little later it starts working and so on. So here's my question. I'm assuming I need to change an injector. Is there anything else it could be that I should check first? It looks like I have to remove a lot of stuff to get to the injectors. Any tips before I start? I've never changed injectors but it seems pretty straight forward and I'm not afraid to try it unless there's a good chance I could screw something up. I ordered 1 injector, can't really afford to change all 6. Can you test them to make sure I change the right one? Thanks for the help. Vince Link to comment Share on other sites More sharing options...
Trogdor636 Posted July 29, 2013 Share Posted July 29, 2013 I've ran a mechanics stethoscope to my injectors when I threw a 51. Its easy to tell which one was the culprit. I actually beat on it with a screwdriver, and its worked since then! Can also do a OHM test I recall. Download the FSM, its around here somewhere. How to section? Garage? I forget. Did you order the proper injector? Yours should have a blue or black dot, the new injector needs to match. Link to comment Share on other sites More sharing options...
Precise1 Posted July 30, 2013 Share Posted July 30, 2013 Yes, like he said! The OHM test is listed in the FSM, available for download free, pinned in the Garage section. IIRC, it is something like 9-14 ohms... Make sure to test hot and cold as I had one that only failed when hot. Also, since it is intermittent, check the wiring as well. Yes, injectors are to be color matched when replaced. As for the ones on the drivers side, If possible, I would replace them all since you have to pull the intake. The ones on the passenger side are easy to get to so they aren't a big deal. Changing the injector is pretty easy, just release the fuel pressure (pull the fuel pump fuse and run it until it dies), remove the retaining cap (be careful, the screws are soft and like to strip), gently twist/pull the old injector out, twist/push the new one in after lubricating it with some gas and be careful not to damage the seal. If your cylinder fills with gas (park so that side is highest to minimize it), remove the coil wire and briefly crank the engine to clear the gas (before installing the injector). B Link to comment Share on other sites More sharing options...
Superkirby Posted July 30, 2013 Author Share Posted July 30, 2013 Hmmmm... I hope I ordered the right one. I didn't realize there was a difference. I'll have to look. I'll download the service manual and see what I can find. I'll also check the wiring. If I find it to be in a lead or something similar, do I have to replace the wiring for the whole injection system? Or can I replace the wiring for just one injector at a time? Thanks again for helping. I'll read a service manual for awhile. Link to comment Share on other sites More sharing options...
Precise1 Posted July 31, 2013 Share Posted July 31, 2013 If it is in the wiring, hopefully you can just splice in past the bad part. Depends where it fails I guess. I'm sure you don't have to replace everything though. It isn't that much to read, it is more that you want a copy for yourself (trust me) and I can't recall the exact values... B Link to comment Share on other sites More sharing options...
Superkirby Posted July 31, 2013 Author Share Posted July 31, 2013 The injector I ordered has a pink plastic top, as do the ones on the Pathfinder now. Is that what I should be looking for or is there something else that determines if I have the right one or not? I went out and listened to the injectors I could reach using a long ratchet extension and I could hear all of them clicking. But then it was idling great and no problems. I took it out and drove it around for awhile and couldn't get it to kick out so I'll leave it until it does and try checking again. I keep hoping it's just some gunk in the injector somewhere and it's working on clearing itself out and I won't actually have to replace it. *fingers crossed* Link to comment Share on other sites More sharing options...
Precise1 Posted July 31, 2013 Share Posted July 31, 2013 They should all be pink plastic topped as per Nunya design. There is a dab of paint that color codes them as well, but I believe it is under the wiring connector boot so you will have to pull one to see. Standard colors are black, blue, silver, mauve, chartreuse, fuchia and some others I'm mixing up at this point. (the first 3 I'm sure about) Yes, hopefully is it a problem that solves it's self, but don't hold your breath, do your best to figure it out. B Link to comment Share on other sites More sharing options...
Nefarious Posted August 1, 2013 Share Posted August 1, 2013 I would run some redline s1 fuel system treatment or run some seafoam in the gas for a tank before replacing if it runs well most of the time. I've had really good luck with both products. Also make sure to inspect the wiring and connectors first before replacing components.. Always best to eliminate the free options before moving to the replacement stage. Ohm test the injectors they should read between 10-13 ohms and in my experience healthy pathfinder injectors read 12 ohm. Link to comment Share on other sites More sharing options...
Superkirby Posted August 2, 2013 Author Share Posted August 2, 2013 How do you check ohms on the ones under the manifold? Or do you just stab the wires wherever you can get to them? Sorry for the newb questions. I'm, well, kind of a newb. Link to comment Share on other sites More sharing options...
Precise1 Posted August 2, 2013 Share Posted August 2, 2013 Remove the manifold. I think you can get to the front one if you remove the dizzy cap, but the other two are buried. Stabing wires isn't a good idea, even if you can locate them, you want an actual reading off of the pins. Yeah, I know, it is a PITA. B Link to comment Share on other sites More sharing options...
Superkirby Posted August 3, 2013 Author Share Posted August 3, 2013 I guess what I wasn't sure about is whether I could pull the manifold and still run it? If so that's not so bad. I looked at the services manual and it says to change the injectors there's a whole list of parts to pull/remove. I figured it would take most of a day. Yesterday I was looking at it and it seems like I should be able to just remove the intake itself and get at it. I'll have to pull the plug wires as well but that should be it to get the manifold off. I did check the 3 passenger side injectors and all 3 were right around that 12 ohm mark, so that's good. Link to comment Share on other sites More sharing options...
Nefarious Posted August 3, 2013 Share Posted August 3, 2013 You don't run the vehicle to test resistance, you do it with the vehicle off. If you are handy, you can remove the distributor cap and gear and use long tools to get at the inside injectors. 1, 2, 3, 5 are easy, just 4 and 6 are a pain but with the distributor removed, they are possible, to test. If you need to replace injectors 4 or 6, the plenum needs to come off. Link to comment Share on other sites More sharing options...
Precise1 Posted August 4, 2013 Share Posted August 4, 2013 I think the point is to test them hot. If so, I'd warm it up and then pull the intake and test them. If you want to listen to them, I think you can get to them with a mechanic's stethesscope and the long bar extension from the top. There is a coolant line back there somewhere, but I think it goes to the lower intake. Otherwise, pulling the plenum is pretty straight forward. Some cables, wires, intake and the bolts and it should come off without a fight. I wouldn't try tio run it without the plenum in place as the MAF and TPS readings will probably freak the ECU out. B Link to comment Share on other sites More sharing options...
Trogdor636 Posted August 4, 2013 Share Posted August 4, 2013 That coolant hose goes to the upper plenum. It was the giant PIA of everything on mine when I had to remove the upper to do my valve cover gasket. I ended up having to slice it in half, it wasn't coming off without being destroyed one way or the other. Link to comment Share on other sites More sharing options...
Precise1 Posted August 4, 2013 Share Posted August 4, 2013 Thanks for clearing that up, I couldn't remember from when I stripped my part-out-pathy. 1/2 the work was done at night or in the rain just before I moved into my house. I didn't have any time and just tore it down as fast as possible. I do recall having to cut a few hoses as well... B Link to comment Share on other sites More sharing options...
MY1PATH Posted August 5, 2013 Share Posted August 5, 2013 I've ran a mechanics stethoscope to my injectors when I threw a 51. Its easy to tell which one was the culprit. I actually beat on it with a screwdriver, and its worked since then! Can also do a OHM test I recall. Download the FSM, its around here somewhere. How to section? Garage? I forget. Did you order the proper injector? Yours should have a blue or black dot, the new injector needs to match. I've been doing that trick for a few months now, Friday it was really hot and that trick wasn't working. Link to comment Share on other sites More sharing options...
gustycrosswinds Posted February 23, 2023 Share Posted February 23, 2023 Did you ever find the OHM numbers for the injectors? I am having a hard time finding it in the FSM. thanks Link to comment Share on other sites More sharing options...
Slartibartfast Posted February 24, 2023 Share Posted February 24, 2023 EF&EC 155 in the '90 manual says 10-14 ohms. EF&EC 137 in the '95 agrees. Link to comment Share on other sites More sharing options...
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