paathfinderr

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.

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.

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

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 ;-(

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 ?

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 ?

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.

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

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

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.

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

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.

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

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

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