craftsman67 Posted October 17, 2011 Share Posted October 17, 2011 Has anyone ever received a false TPS code for a bad O2 sensor? All voltage test check out ok on the TPS. This is the only code the ECM is reading. I am trying to check the O2 sensor from the FSM check list, and it says to check voltage when A.I.V. system operates...is this the Air Induction Valve? If so, can anyone tell me where it's located on my 87 Pathy? And how to do this??? The FSM doesn't specify how. Any suggestions will be greatly appreciated. Thanks!!! Scott Link to comment Share on other sites More sharing options...
sewebster Posted October 17, 2011 Share Posted October 17, 2011 Did you check the voltages at the ECU connector? Could be a bad wire if you just checked at the TPS. Could also be an intermittent problem. Or a bad ECU... Link to comment Share on other sites More sharing options...
craftsman67 Posted October 17, 2011 Author Share Posted October 17, 2011 Did you check the voltages at the ECU connector? Could be a bad wire if you just checked at the TPS. Could also be an intermittent problem. Or a bad ECU... Link to comment Share on other sites More sharing options...
craftsman67 Posted October 17, 2011 Author Share Posted October 17, 2011 Yes, we did check from the ECU as the FSM instructed...My friend romoved the top of the ECU and visualy inspected it for burnt or broken connections, but didn't see any. Is there a test for the ECM? Link to comment Share on other sites More sharing options...
craftsman67 Posted October 17, 2011 Author Share Posted October 17, 2011 Yes, we did check from the ECU as the FSM instructed...My friend romoved the top of the ECU and visualy inspected it for burnt or broken connections, but didn't see any. Is there a test for the ECM? I ment ECU...duh! Link to comment Share on other sites More sharing options...
Slartibartfast Posted October 18, 2011 Share Posted October 18, 2011 I'd be more suspect of the wires than the computer. I've only heard of a few people losing the computer, and that was usually either a result of flooding it with water, or a mysteriously (but obviously) blown resistor. Also iirc you have to disconnect the battery to clear the codes, so if you think you've fixed it, clear the code and see if it comes back. Link to comment Share on other sites More sharing options...
Kingman Posted October 18, 2011 Share Posted October 18, 2011 (edited) I've had those codes come up when there wasn't anything wrong. The truck didn't run any different after I unplugged the battery, so I ignored them. Clean ALL grounds if you haven't already. They're extremely important to Nissan ECUs. The AIV is an emissions component. On a TBI engine it's right by where the intake tube meets the fender. Not sure on how to test it as I laughed at it and threw it away a long time ago. Edited October 18, 2011 by Kingman Link to comment Share on other sites More sharing options...
JamesRich Posted October 18, 2011 Share Posted October 18, 2011 The problem your having is the 87 codes are different from the 89 FSM. In the 87 a code 43 is the injector, same as the code 51 in the 89 FSM. Here is a scan of that page from the 87 FSM. My book is kind of brittle so I don't want to push it down too hard on the scanner. You should be able to follow the trouble shooting for code 51 in the 89 FSM. Keep watching ebay to try and pick up a 87 copy of the FSM, I'm finding more and more differences that make this book worth having. James Link to comment Share on other sites More sharing options...
craftsman67 Posted October 18, 2011 Author Share Posted October 18, 2011 The problem your having is the 87 codes are different from the 89 FSM. In the 87 a code 43 is the injector, same as the code 51 in the 89 FSM. Here is a scan of that page from the 87 FSM. My book is kind of brittle so I don't want to push it down too hard on the scanner. You should be able to follow the trouble shooting for code 51 in the 89 FSM. Keep watching ebay to try and pick up a 87 copy of the FSM, I'm finding more and more differences that make this book worth having. James Well that explains it...my friend kept saying it sounded like the injectors were acting up. I'll check this out. Thanks James! Link to comment Share on other sites More sharing options...
Kingman Posted October 18, 2011 Share Posted October 18, 2011 Good catch James. That would make more sense as the TPS is mostly used as an idle, half throttle, and full throttle switch for the ECU. There's a potentiometer inside as well to control an automatic transmission (the extra 3-prong plug). What are the injectors doing that's not normal? Link to comment Share on other sites More sharing options...
craftsman67 Posted October 18, 2011 Author Share Posted October 18, 2011 Good catch James. That would make more sense as the TPS is mostly used as an idle, half throttle, and full throttle switch for the ECU. There's a potentiometer inside as well to control an automatic transmission (the extra 3-prong plug). What are the injectors doing that's not normal? When I can get it to idle, you can see the fuel in the TB pool up, and then get sucked into the engine...I was wondering about the extra prong on the TPS with no wire connection. It is a 5 speed. The TPS connector was corroded pretty bad. I cleaned it with some contact spray, pipe cleaner, and a tooth brush. Do I need to disconnect the battery every time I check the ECU? Doesn't it clear when you shut the key off after checking it? I thought I read that in the 89 FSM. Link to comment Share on other sites More sharing options...
Kingman Posted October 19, 2011 Share Posted October 19, 2011 I think there's a way to clear the codes without unplugging the battery but I've never done it that way. The only way to reset it though is to unplug it. Link to comment Share on other sites More sharing options...
JamesRich Posted October 19, 2011 Share Posted October 19, 2011 I'm sorry guys, when I posted the scan page from the FSM I was in a hurry and didn't notice it was so small and useless. Notice also the all clear code is 44 instead of 55 I wouldn't know how to clear the codes either, I use my old snapon scanner. James Link to comment Share on other sites More sharing options...
craftsman67 Posted October 19, 2011 Author Share Posted October 19, 2011 I'm sorry guys, when I posted the scan page from the FSM I was in a hurry and didn't notice it was so small and useless. Notice also the all clear code is 44 instead of 55 I wouldn't know how to clear the codes either, I use my old snapon scanner. James Much better! Thanks James. Link to comment Share on other sites More sharing options...
craftsman67 Posted October 22, 2011 Author Share Posted October 22, 2011 After this test... http://ww2.justanswer.com/uploads/heavychevy396/2010-11-16_221619_1986_nissan_d21_rough_idle.pdf ...I am now pretty sure that I have a bad, or clogged injector. I have a friend coming over Mon. with his injector cleaner thing, not sure what it's called. We're going to try to clean it from the fuel line, before I buy a replacement....Can the rebuilt ones be trusted??? The new ones ain't cheap! Link to comment Share on other sites More sharing options...
sewebster Posted October 23, 2011 Share Posted October 23, 2011 You can get injectors cleaned and tested probably for around $20 each. Then you'll know they are good (full flow rate characteristics etc.) Look for a fuel injection place. If its easy on a TBI you could drop a new/rebuilt one in though. Bit of an annoyance on the VG30E so I think testing is worth it for that engine. I did buy a new one for $200 or so from the dealer last year... I was in a rush. Link to comment Share on other sites More sharing options...
craftsman67 Posted October 23, 2011 Author Share Posted October 23, 2011 You can get injectors cleaned and tested probably for around $20 each. Then you'll know they are good (full flow rate characteristics etc.) Look for a fuel injection place. If its easy on a TBI you could drop a new/rebuilt one in though. Bit of an annoyance on the VG30E so I think testing is worth it for that engine. I did buy a new one for $200 or so from the dealer last year... I was in a rush. Thanks for the info. I did a local search and found a place about 10 mi.from my home. I going to call tomorrow to see what they charge. Hopefully this could be a time, and money saver! Thanks again! Link to comment Share on other sites More sharing options...
craftsman67 Posted November 4, 2011 Author Share Posted November 4, 2011 I had a local shop clean the injectors...I reinstalled the TB, and I'm back on the road! A $40 fix cost me close to $500... But I now have a new MAF, TPS, and Throttle Chamber Assembly. I guess I'll keep the old ones for spares. Link to comment Share on other sites More sharing options...
sewebster Posted November 4, 2011 Share Posted November 4, 2011 Always good to get it solved! Link to comment Share on other sites More sharing options...
craftsman67 Posted November 7, 2011 Author Share Posted November 7, 2011 I'm still having problems with one injector after having them cleaned...I guess I need a new one. I installed the good one on the drivers right side, with the bad one unplugged, and it seems to run fine as long as I don't go over 2800 rpm...Is it ok to drive it in limp mode, until I can afford to get a new one? Or should I just park it to prevent any other damage?... What can it hurt?... This is my only ride! Scott. Link to comment Share on other sites More sharing options...
Kingman Posted November 7, 2011 Share Posted November 7, 2011 I've got some used injectors from my truck, could probably use a cleaning but they do work fine. That is if you don't want to pay a premium for a brand new one. If you're interested PM me, we can probably make something work. Link to comment Share on other sites More sharing options...
sewebster Posted November 7, 2011 Share Posted November 7, 2011 Did they not flow test them etc to see if they work properly? Link to comment Share on other sites More sharing options...
craftsman67 Posted November 7, 2011 Author Share Posted November 7, 2011 Did they not flow test them etc to see if they work properly? Not really sure...every time I called and tried to get some info, they were at lunch, and nobody could answer my questions...Who takes lunch at 3 in the afternoon??? When they said they was ready,I just assumed they were ok. I'm not really happy with the way they treated me. I never got one call from them when I asked them to call me back and let me know SOMETHING!!!....and it took over a week! Link to comment Share on other sites More sharing options...
sewebster Posted November 8, 2011 Share Posted November 8, 2011 Not really sure...every time I called and tried to get some info, they were at lunch, and nobody could answer my questions...Who takes lunch at 3 in the afternoon??? When they said they was ready,I just assumed they were ok. I'm not really happy with the way they treated me. I never got one call from them when I asked them to call me back and let me know SOMETHING!!!....and it took over a week! That sucks. When I had mine done I got a printout with all kinds of data about each injector and how it performed. I chose to replace one as a result. Link to comment Share on other sites More sharing options...
craftsman67 Posted November 8, 2011 Author Share Posted November 8, 2011 That sucks. When I had mine done I got a printout with all kinds of data about each injector and how it performed. I chose to replace one as a result. Really? All I got was a cheap looking, computer made invoice, with no info except Amount Due-$40. Link to comment Share on other sites More sharing options...
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