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paathfinderr

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Everything posted by paathfinderr

  1. Hi Slartibartfast, Thanks. You're right of course. I can't argue with your logic. And thanks for the idea of jumpering to another idiot light to avoid the CEL failing bulb check. I also agree that if the mixture is off that far, the sniffer will likely notice. If I do try this I'll be careful not to hack up the harness! Changing all the injectors - as I did initially - was a bear of a job, and I'm willing to give almost anything a try to avoid having to redo that. I only need the truck to pass one smog check in order to complete re-registration. I'll then either sell it, or take it to a "no smog check" state. I'd do that now, but I think most states require a valid current registration to re-register there. But thanks for the encouragement to do it right, and for following my posts for so long! I appreciate it.
  2. Greetings all, Well, I'm still on this project (or maybe I should say, back on it). At this point since my Pathfinder runs pretty well, I'm trying to figure out how to disconnect the CEL. Other than disassembling the dash and finding the ground or power wire(s) to the CEL harness, or removing the bulb, is there another way? I suspect/hope the truck might pass an emissions test now, but it will fail for sure if the CEL is on. Thanks again.
  3. Greetings all, Does anyone know which pin(s) on the ECU power the CEL on a 1992 Pathfinder? Not which pins trigger the CEL, but which pin(s) supply power to the CEL? I want to be able to prevent the CEL getting power regardless of any triggering events/faults/codes. Thanks a bunch
  4. I removed the MAFS along with its housing (the part which goes from the air filter to the large ribbed intake duct), removed the air filter and its housing and cleaned out everything. It all looked clean. I removed the same parts from my 95 Pathfinder and compared the "resistance" of the intake ducting inside the fender on each to either suction or blowing from my shop vac. I was surprised to notice that for both trucks this inside the fender duct definitely wasn't free flowing. But the other intake behind and above the headlight was. So its getting air. I installed the MAFS and housing from the 95 onto the 92 and did a road test. It performed identically to how it had with the original MAFS - no closed loop unless its under load, CEL after 15 minutes or so, code 45. I'm fairly confident the problem is not the MAFS. I started off in Mode 2 and for the most part while driving in presumably closed loop I got synchronized red and green flashing lights, which I believe is alternating between 5% rich and lean as it should. I'll repeat this road test shortly. I like your analysis a lot. Thanks. Next I'll look for the EGR to BPT connection. And run another ground to the exhaust. Then I'll work on the fuel pressure and leak down test. After that I'll remove each spark plug in turn and look for wetness. My best guess as per your analysis above is a small leak. Maybe one of those new injectors ;-(
  5. Thanks! Yeah, happily I didn't start pulling everything apart looking for leaking injectors immediately after seeing that code! I'll check the EGR hose you mention. I'd love to find it be something simple like that. Funny thing is, the truck runs really, really well - up hills, on the freeway. I'd hope that a misfire would show up with crappy performance or a code. Thanks. Plugs are good, wires are solidly seated. Once I get it up and running without these funny no closed loop when parked, etc issues I'll get a smog pre test done. Maybe then it will be time for a cat change, but until these issues are ironed out I can't even think of that step ?
  6. Thanks. This is way, way deeper than I want to, or could, go ? But reading what My1Path did is unbelievable! I'm stunned. I just wanna get my old 92 running and pass smog ?
  7. No worries, Mr R. I'm learning a lot every day. Its interesting how standards develop, and frustrating to deal with pre-standards equipment. I guess there are not really enough of these trucks to warrant making an interface with the complete ECM connection and outputting the data to a connector compatible with the latest Consult and other after market boxes. I'm sure it could be done, probably in a weekend fueled by pizza, by a group of kids. I did find one guy who makes an ECM connector with short wires that go directly to another ECM-side connector - allowing one to hook into these connecting wires instead of the harness. I'm faintly curious which year model Pathfinders had the "big blue" plug ECMs and when they switched to others. I looked at 2019s and the ECM plugs are completely different.
  8. If that's good enough for someone who works on cars to the level you do, its good enough for me! Thanks. Thanks also for the fuel pressure gauge info. And your analysis of the closed loop dilemma. That's what experience allows you to do! Yes. I was under the (mistaken?) impression that Mode 2 would only work when entered while the truck was in closed loop. Since it only ever gets to closed loop when actively driving I need an extra set of hands to reset to Mode 2 on the fly. But maybe I can just start off in Mode 2 and once the truck goes closed loop while driving, Mode 2 will function. We'll see. Many thanks to both of you. Have a great weekend
  9. Thanks. Yeah the problem as far as I can understand it is that the port on my truck is a 12 pin, with only about 8 or 9 used, the rest are empty. I called a few people yesterday about this also, including a very nice guy at M2K who was willing to sell me a Consult 1. Here is what I believe to be the best explanation of the 12 pin port: " The 12 pin connector is for diagnostic tool MST-4987 and is nothing more than an LED box that indicates the state of the various engine solenoids, and also the diagnostic LEDs. " Its from: https://www.tapatalk.com/groups/eccstech/australian-d21-t1554.html This would explain why a remote flashing light checker can be wired into this port. I've also seen this port called a check connector checker port. I guess its possible that more info can be sourced from this port by the right software or tool, but I have yet to turn up a connector for this 12 pin port. One thing for sure its not compatible with the 14 pin connectors which apparently were common on most earlier Nissan vehicles other than Pathfinders
  10. Its got to be a pretty serious problem to plummet to earth - like the wing falling off, or someone trying to fly too high. A little like thinking because its 4WD you can jump up a vertical 5 ft curb at 60mph. Does anyone make a connector or adapter for this OBD1 port? There is a lot of Consult type bootleg software out there if there is actually useful data available at that plug. I'm sure by now you guys would have found such a plug if one exists. I'd even make up a bunch in China and sell them if I could find one, and it plugged into a helpful reader. I'll call a couple of places and ask them, like https://www.scantoolshop.com/consult-usb and http://www.nissandatascan.com/ I read all the posts on that link you sent. Thanks. Yeah, I won't get into body panel removal just yet. What sealant do you use after you take the fender or another panel off? I'll get to it sometime I'm sure. I'll do the leakdown test. I got a fuel pressure gauge for an Explorer but it has a shrader valve on the fuel rail so its a little easier than putting one in line. Any recommendations? Fortunately (??) timing is checked during the smog test in CA - mine is 15 BTDC and indicates Pass. This test was done after I did the big work. I've done road tests daily recently. The puzzle to me is: why I can't get closed loop when stopped. Closed loop happens immediately I start driving up my street, as soon as I'm moving and not in idle the green light starts flashing. It keeps flashing all the time, at all speeds unless I'm at idle. I guess I could put the truck in neutral and be moving and not at idle and see what happens then. After about 15 minutes when driving I get a CEL, and a red fault saved indicator (its a CA requirement I think). The green light though keeps on flashing as before. If I stop, and park but don't shut off the engine, and try 2000+ RPM sometimes I get a green light, usually but not always on revs decreasing, steady once, not flashing, and then the CEL goes out, and the red light goes out. Although when I check later, parked, shut off, 45 is still in memory. Have a great day.
  11. Ha! No salt slurry in CA, but the salt air is present 24/7. Everything gets corroded ? So far I hard wired an addition ground to terminal B of the MAFS connector, and it didn't change anything. I fly jets for a living and I'm beginning to share the frustrations of the mechanics we report problems to and who do what seems like everything possible and its still not fixed. Thanks for the tab idea. I don't have a welder so I'll look for a tab already in place, or a bracket or something and clean it up well before adding the ground strap. Best regards john
  12. Yeah, sorry I could not attach the full smog check. Its a little more clear than that snippet I cut off to meet size of uploadable file restrictions. GP means Gross Polluter. Above this level CA gives you some rebate for repairs and many years ago gave $500 to scrap the car. I did that with a 1981 VW Scirocco I had since new. The odometer stopped working but I put over 500,000 miles on it. Original engine, clutch and transmission!! Yes, meas is measured, O2 zero, CO2 12.7% HC was high, above Max but below Gross polluter, CO was above GP, NO or Nox above Max but below GP. Results were Gross Polluter because of CO Yes, my O2 sensor is 3 wire. Rock Auto seems fairly good at accurately matching parts to the vehicle, plus it seems to be working well now. Great idea about new grounds to the exhaust. I'll do that. I see two straps at least to a manifold heat shields. They both are intact, but I'll bet 10c that the bolt will shear if I try to loosen it - much rust. I'll make/drill new attachment points. Thanks again Mr R. Much appreciated.
  13. To no-one here's surprise I'm sure, I got nowhere with the dealer. The nice guy I was talking with was an order writer so his job is to get my keys and signature. He did say that all his guys could get would be the same data I has getting by reading the flashing lights, plus a little more detail. How much more detail? He called his master tech and asked how much more info CONSULT could get from my computer. When I mentioned that my truck is apparently not set up for CONSULT (nor does it have an ODB1 port, right? Just what is that 12 pin connector near the hood release. Its just a flashing light repeater, or is it more than that. I'm curious and would love to know - I did not have this discussion in parentheses with him), he said CONSULT would connect wirelessly with my ECM. Now that would be very cool. I don't know that much about computers but I'd bet a solid 25c that no ECM built around 1990 had wireless connectivity capability. So do they plug into the the 12 pin connector? Do they have a connector with wifi which goes between the ECM and the ECM connector? Now that would be cool, but I can't see the demand being sufficient to warrant the expense of building one by the dealer or any component maker. Any ideas? He did finish by saying a scan of my truck would be $150. Say $200 out the door. I can throw a lot of parts at this truck for $200 so I declined since I don't need a readout that my computer has code 45 stored. I know that already. Its mildly amusing to me that a stock low price alert I had entered years ago for Nissan stock, came up as my first email this morning! How did you access the behind the fender resonator box? I've looked at your "other project car" site so I know you're not afraid to disassemble things ? Thanks for the funny story. Since the consensus is focused on the MAFS I'm going to disassemble the filter box and clean out both resonators and if access makes it feasible also screen off the intake. Great idea!! I'd sure my 95 has the same problem. Then I'll solder a new ground to the MAFS B terminal and ground it to the engine ground If the problem continues I'll take the MAFS assembly off my 95 and install is it on my 92 (assuming it passes visual inspection that it is pretty much identical. After that I'll follow all the instructions on NTB95-021 but I may ask you for recommendations for fuel pressure gauges and other tools I'll need Have a great day. I've noticed researching things that you've answered almost all my questions some other place, years ago. I much appreciate your patience answering again. john
  14. Awesome, thanks. I found and downloaded NTB95-021. Too bad Consult can't be used on this truck. Looks like its pretty amazing. If my Mossy Nissan guy has something similar it doesn't look like just a simple one time scan will tell all. Consult seems pretty specific to issues suspected. But I'll see. It will help to establish a rapport with them if possible, or even to learn that they won't help me ? Great analysis on the extra air when driving. Implies that I'd still fail the smog test. No worries, you saved me the $30 they would charge me for a failed recheck. Gotta sort it our first. I'll check the air intake plumbing, filter box, etc. When I first started on this some rodents had found a good home there. Maybe I left something further upstream when I cleaned out the filter box and replaced the filter. I tightened most of the connectors to the pins on any of the many connectors I opened so far ? 021 also shows how to take the female connector out of the connector. Thanks again my friend john
  15. Ok, I lied. I'm still working on it. I retightened the ground near the ECM, and after reading about MAFS shield grounds I jumpered an additional ground to the MAFS connector (its a Mickey Mouse arrangement but I wanted to see if it made a difference). Did a couple of road tests including a bunch of hills and some 65-70mph freeway. I get normal closed loop operation in normal driving not in idle! This is a big plus. I do not however get closed loop (flashing lights) at any RPM when I'm stopped. The 45 leaking injectors came up once on one drive, and the CEL flashes on occasion. I cleared the 45 again and it did not recur. On shutdown I checked codes and the only one is 55. I think I'll still go see Mossy Nissan and see if they'll do a scan because that might help me narrow things down. But I don't at this point think its critical. My truck might even pass smog now because they run it on the treadmill, so its not stopped. Obviously its not perfect yet. What are your thoughts about the extra ground Nissan MAFS connector? If I can find one its not big bucks. Otherwise I'll solder a new ground onto the MAFS connector ground wire. I'd like to solder it onto the female connector but I don't know how to remove the female connector from the connector assembly. Thanks again guys. Without your help I'd be lost! Have a great day John
  16. Greetings friends, After working on some grounds and checking all the diagnostics modes and still showing no closed loop operation, and no codes, I took the truck for a test drive. Sure enough I got green closed loop flashing (sometimes) and a check engine light. The stored code was the one I did not want to see - 45 - leaking injector. Ha! So its back to the 137 step process I did to change the injectors! I'll take a break from this project for a few weeks, and do something else easier - like fix old lawnmowers for my property. I had a nasty suspicion that all the injectors did not seat as firmly as the others, so... Thanks again for all your support and help. I'm not done yet and I'll post the next steps as I encounter them. Have a great day John
  17. Hi Guys, Thanks again. Brainstorming this last night after rechecking O2 sensor and its connections and continuity of these, I'm curious whether I'm looking at this "not getting into closed loop" backwards. Could the mixture be too rich, from some as yet undiscovered cause, to permit closed loop operation? From what I understand closed loop operates in a pretty narrow range, going back and forth from being too rich to too lean but not by huge amounts. What if the mixture is far too rich, the O2 sensor tries to make it leaner, but gets to its limit of control so never crosses into the too lean area so never cycles, so there are never flashing green lights? Could the mixture be that far too rich without throwing any codes? Please correct me if my thinking is off base. The manual does call for checking various components if the Mode 1 blinking light test continues to be NG. Today I'll recheck for any codes, and do a road test also. I'll try anything, so long shots are welcome. Some of the gas has been in the truck a while - maybe 2 years - but I've topped off with fresh whenever possible. I'll work on this too. As a side note, I theorized that the throttle position switch was stuck at "wide open throttle", which supposedly causes open loop operation. The 94 and 95 manuals both show tests for this but the wiring diagrams show this TPS wire as "not used". The 92 TPS connector has no female connection in the plug wire going to this sensor so getting stuck in "TPS switch wide open throttle" isn't possible. My 95 however, contrary to both manuals, does have a connection (and tests fine according to the manual tests - throttle released, no continuity; throttle fully depressed, continuity). Yes, I checked that line yesterday. No fuel in it. So the scanner will be able to see these reading? That's hopeful and a good reason to try to get Mossy Nissan to give me a read out. I wasn't hopeful they would, but now I'll try harder ? Yes, mine is a CA spec truck. And of course since I changed the injectors (a real bear of a job for a non-mechanic!) that was the first thing I suspected. And it still might be the case. But no codes so far. The new O2 sensor looked identical to the old one, same appearance, same size of everything visible. I now suspect the old one wasn't bad. Thanks for this. My cat may well be bad and even after I fix the open/closed loop issue I might still fail emissions because of the cat, but that's a step down the road. Getting to closed loop ops is my first priority, even if that doesn't make the truck pass emissions ? Attached is the smog readout - I'd give you the whole thing but I'm limited in file upload size permitted ? Snap On Verus Pro looks like a great tool. A little pricey on eBay right now - more than this Pathfinder is worth. Fortunately for my sanity I don't count the hours I put in at any hourly rate!! Again, thank you both so much. I'm in awe of your knowledge and experience and your willingness to assist. Long, long ago when my junk old vehicles had either a broken steering link (bought from an auction) or I took the engine apart to change the timing belt and got in waaay over my head, I just got rid of them. This one I'll sort out. But I'm not taking the intake manifold off again unless I know for sure something - like an injector or the fuel pressure regulator - is bad! Have a great day john Smog basics1.pdf
  18. Hi Slartibartfast, Thanks again. Please see my reply above to Mr Reverse also. Yeah, my smog guy doesn't even look at the ECM on these older vehicles. I think all he cares about is that the CEL (check engine light) is not on. And it hasn't been on other than once when I drove back from the smog guy! Not since after maybe 20 starts, and battery disconnects. No two or four flashes, and since the replacement ECM indicates precisely the same as the original, I'd guess that rules out being stuck in other than Mode 1, the default mode. No other symptoms at all! No black smoke, easy to start, smooth idle. I'm going to again go over all the O2 sensor (which was replaced with new) and CTS (which I verified has a resistance drop very close to that of a new one when exposed to normal engine operating temps) component and wiring checks - since this is what is called for in the WSM if the green - closed loop - light does not flash correctly. Thanks again john
  19. Hi Mr Reverse, Thanks. This was my feeling exactly - that dealers would not have useful diagnostic equipment for old vehicles. We might both be right, but a very helpful sounding guy at my local Nissan dealer - Mossy Nissan - said he has an amazing $25k computer that can be hooked up to an ODB1 vehicle and give a roadmap for finding problems. I'll meet with him on Wed, detail all I've done so far and ask if he's willing to do whatever scan they can do, as long as its more than just reading ECM codes, and give me a print out. If not, I'll keeping beating my head against the wall. If he does I'll let you know and find out what equipment they used. My best guess is the problem is something I've messed up in working on the Pathfinder, but I still need to find the problem! The guy at the scrapyard who sold me the replacement ECM suggested I double check all grounds. So I'll do that. The first thing I did was run an emissions test. It failed as a gross polluter - meaning ALL readings are above max! The history is that the truck had passed emissions tests for years, then it just sat in my driveway aside from occasional starts. Then last year it failed emissions. I did the simple things - change plugs, plug wires, air filter. Then I checked the resistance of the injectors and found 4 out of six bad. So I replaced all 6 injectors with new. I felt like a hero when it started right up. Headed to the smog place and it failed as noted above. So I started to look for codes. No codes. Then I checked to see if the truck was going into closed loop. No. So I started trying to learn all the reasons it might not and either checked relevant components and their wiring/continuity to ground/ECM connector or replaced them. This is where I am today. Glad you're still passing emissions, happy for you its just Federal. From all I have learned, and from comparing my 95 Pathfinder which is fine, and passes, closed loop is required for normal ops, is indicated by flashing green ECM lights, and the ECM defaults to Mode 1 on switch off. This is pretty much confirmed by the replacement ECM, and by disconnecting the battery about 20 times so far ? All ideas appreciated. Thanks. Please also see my reply to Slartibartfast below.
  20. Hello again, Well, that's a bust. Replacement ECM indicates and works precisely like the original. Do you know if Nissan service centers have any special diagnostic equipment they can plug into the ECM harness or anywhere else? I'm reluctant to spend big $$ per hour to have a dealer's guy just to repeat all I've done, but I've run out of things to try. Have a great day john
  21. Good morning Yeah, I've pretty much done all that. Vac lines all replaced, CTS, MAF, TPS wiring and sensors checked. The MAF filament was good, and clean. I have an ECM with the same part number coming from a junkyard, although my best guess is its not the problem. My ECM does detect and indicate codes - when I ran the engine with the CTS disconnected it immediately lit up. Plus on deceleration from 3000-3500 to idle I do get a green light briefly and quite consistently. This problem has me puzzled.. Thanks again for your comments - its helpful to know I'm not missing something obvious. My understanding is that the TPS switch does not use the connection on the sensor which would sense full throttle operation, only the one which senses idle ("soft idle") Have a great day john
  22. Thanks for sharing that. Its called experience!! No codes. I'll search for essential items for closed loop operation. I understand the coolant temp sensor is one. I've got a new one in hand but maybe I'll get my hands on a 2k ohm resistance which is what the manual calls for as a check, since apparently the CTS resistance drops the that value once its warm. From what I recall, open loop mode is for: initial start up, cold ops idle hard acceleration Sensors involved in conveying that info to the ECM include: CTS TPS MAF Accelerator position sensor Anything else? Of course after all this it will likely be a leaking vacuum line. So of course I'll change out any that don't look 100% I guess the ECM could be bad also? Best regards John
  23. New O2 sensor installed. Vehicle starts right up and runs find. However, still the same issue. After warming up there is no flashing green light indicating closed loop operation on the ECM at any RPM. But the light does flash when I "blip" the throttle, from 1500 to 3500 and release it. But only flashes while the RPM is transitioning. Any ideas? I'm not sure how the TPS functions or whether this might be the issue. Fortunately I have the fully operational '95 so I can try various parts from that. And ideas and help welcome! Thanks john
  24. Hi Slartibartfast, Again, thank you so much. This is precisely why I joined this forum - to connect with someone with vastly more experience than me at dealing with these things. I found a Nissan pin out numbering diagram so now I can at least identify the correct pin numbers on the ECM and the connector. My mistake. Exactly as you describe - B has continuity to 19 at the ECM connector as it should. B wire is white. (This continuity - pin 19 lighting up - was exclusive, so no crushed wire to ground shield) Also, exactly as you describe, the black wire from A grounds the O2 connector. And C is black/white and has 12V with ignition on. So, my wiring all checks out. You saved me by identifying the A black to ground on '92 vs A black/yellow to 106 on '95. This difference led me down the garden path!! (My '92 ECM connector has a black/yellow at pin 34 I mistook for 106 so that helped too.) 106 on my '92 connector is empty - just as your '90 manual shows it crossed out in the '90. So both your '93 and my '92 as you say are more like the '90 manual than the '95 manual in this regard. Next step per FSM is to replace the O2 sensor. Funny, this was my initial inclination - to throw parts at the problem. Now I understand it a little better, even though the next step is the same. I really, really appreciate your help. Have a great day john
  25. Hi Startibartfast, Thanks. I'll need to figure out how the pin numbers are calculated, and I'll count them in the morning. Thanks for confirming that the O2 black wire goes to ground. That checks out with my 92. And yes with ignition switch on, per the 95 manual, I have battery voltage on the black/white wire (again I'll check its color in the morning - today I was going by O2 harness (a) (b) (c)). Definitely pin 19 is not in the same place on the connector on my 92 as it is on the 95, but if I figure out the numbering I'll see what pin it does have continuity with (I did check and it does indeed have continuity with one pin on the connector, just not the one shown as 19 in the 95 manual) Much appreciate your most helpful response. Definitely confirms at least I don't have to rewire the black to pin 106. Best regards john
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