Guest bastaad525 Posted July 14, 2004 Share Posted July 14, 2004 Okay guys... sorry I'm posting this here but I've already tried posting at three other forums about this and got not one reply... friggin rediculous. But I figure here there's at least a good chance someone will know and have the free time it takes to type up a reply. I promised myself I would try to NOT post stuff here re: the Sentra I recently bought but my only other option is to pay someone lots of money to try to figure out the problem. Well here's the deal. The car is my '91 Sentra SE-R. The fuel injection is nissan's ECCS system... dont know how similiar or different from the ECCS' in Z's. It is OBD I. The car has been running great, but has an oddball problem. Every few days, it will light the check engine light. When this happens, the car will suddenly almost refuse to idle. It will idle okay until I touch the throttle, and it will rev okay and drive okay, but as soon as I let off the throttle the motor tries to stall, sometimes it actually does die, usually the idle bounces around a bit. I went down and picked up a Haynes manual, and followed the procedure for using the computers self diagnostic feature. The computer gave me a code 45, which according to the haynes manual, stands for a leaky injector. So, with the motor running, I took a really good look at the injectors, and saw NO sign of any leakage whatsoever. There is also no smell of fuel that would tell me there is a problem... Nothing. If I then erase the ECU's trouble code, the car goes back to running fine again, until after a few days the light comes back on. So I'm at a loss. Anyone here have any ideas what else I should maybe check? I thought the OBD was gonna be a nifty thing to have (heheh yeah... nifty)... I mean... what's more cool than a car that can tell YOU what is wrong with it!? I figured it was just gonna pinpoint some sensor and I would be done with it... instead I get this mystery. Well... there it is... any help or advice would be greatly appreciated Quote Link to comment Share on other sites More sharing options...
strotter Posted July 14, 2004 Share Posted July 14, 2004 I know *nothing* about Nissan ECUs, nothing, nada, but it sounds to me like it's going into "limp home" mode when it throws the error. Limp Home is a state where the computer goes into a very conservative state, and stops trusting its' sensors because there's some problem which might make them untrustworthy (such as if you have a leaky injector, which will botch the O2 reading). The idea is that it'll run in such a way as to not cause further damage (super rich, very conservative timing, little EGR cycling, that kind of thing). American cars in this mode (which I have a little experience with) will just *barely* run - only well enough to get to a dealer, basically. I expect it's trying to tell you "Fix the d**n injector!" Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 15, 2004 Share Posted July 15, 2004 yeah, I figured the idle problem was 'limp mode', though I'd never heard of limp mode causing the car to die like that, everything I've heard says limp mode basically kills the engines power off and wont allow you to rev past some super conservative point, like 2500rpm or something. Oddly, when this car does it, it doesn't seem to have either of those two problems... just tries to die every time I let off the gas. If an injector is leaking there is NO indication of it. I don't see/hear/smell ANYTHING with the motor running. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted July 15, 2004 Share Posted July 15, 2004 I had a regular 91 sentra. It had two things that made the car act that way. One was the wiring connector to the Mass Airflow Sensor. The second thing was the wiring harness to one of the injector's was broken as well. Considering the under hood heat and the age, the wire's and connctors become brittle. Hope that helps. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 15, 2004 Share Posted July 15, 2004 yeah I checked the wiring connectors at the injectors... they appear fine. MAF connector appears fine as well. Really odd... well I've driven the car the past two days and it's fine again... annoying. I might pull the injectors and have them cleaned or something. Also I'll probably do like I have on my Z and go and try to clean all the electrical connectors I can get to, and then put dielectric grease on them. Seems to be working great for my Z. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted July 15, 2004 Share Posted July 15, 2004 What is the exact wording of the Code 45 from the Haynes manual? If it says a leaking injector it might not mean externally leaking it might mean the injector is leaking internally cause that cylinder to run extra rich. Does your car have an IAC, idle air control motor? If it does take it out and see if its ok. I have seen IAC's do this exact concern. If the IAC is not working all the time it will cause the car to die when you are not pressing on the gas pedal. Guy Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 16, 2004 Share Posted July 16, 2004 the wording is pretty vague... it really just says "leaking fuel injector" in the haynes. yeah I had considered it's leaking on the inside... guess I'll have to pull them off to find out... odd that it only does it once or twice a week though... I'd think if it was leaking it'd do it all the time. I dont have any rich smoke or anything and my 02 sensor reports everythings A-OK. yeah the car has an IAC... I HATE these things... you NEED the computer to control idle... that is so stupid. I want to take mine off and check it out but it is VERY hard to get to on this car, A/C pipes are in the way and it doesn't help that I have large hands but even my wife with VERY small hands couldn't get a grip on it to disconnect the wiring connector from it. Funny thing is the idle problem seems very common on SR20DE motors, at least I see it mentioned a lot of times on the SR20DE forum and nissan forum... and there is a whole list of things to try to fix it... most of which I've tried already. Unfortunately, there are some on those boards who claim they've tried everything listed and not gotten rid of the problem still. As much as people seem to love these cars, one visit to either of those forums will reveal that they are BUGGY beasts, to be sure.... Quote Link to comment Share on other sites More sharing options...
80LS1T Posted July 18, 2004 Share Posted July 18, 2004 When I go to work on Monday I will see if I can print out a copy of the diagnostic procedure for a code 45, from SHOPKEY(same kind of program as, ALLDATA, MICHELE ON DEMAND,ETC). Guy Quote Link to comment Share on other sites More sharing options...
COZY Z COLE Posted July 18, 2004 Share Posted July 18, 2004 If you have looked at this, sorry, but the SE-R FAQ, in the erratic idle and jumping idle, mentions your error code and gives some things to check. http://www.se-r.net/faq/index.html On the left column click the search the FAQ and then enter, error code 45. Click on the first item found and this is under common problems. LARRY Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 19, 2004 Share Posted July 19, 2004 Larry - yeah I have been over the faq at SE-R.net a few times... and I KNEW I had seen some mention of the leaky injector code before... goes to show how hard it can be to find things right under your nose some times. Thank you for digging that back up for me though. Actually I've been thru those two sections (the funky idle problem and the bad gas mileage problem) a few times and have tried most everything in them, inlcuding: Testing the O2 sensor (with a voltmeter and also using the ECU's self diagnostic function, it passed both with flying colors, supposedly the dealer replaced it before I took the car... supposedly) Cleaning out the throttle body ATTEMPTING to set the idle properly (IAC valve not acting properly... now I know that that can have something to do with the injector leak code) Tested the ground voltage of the MAF (was well below the limit) Adjusted the TPS Cleaned the spark plug wires Nothing has fixed the idle, I do get so-so gas mileage (about 24mpgs), and yeah that code... the last thing I know I can do is try to remove and clean the inside of the IAC valve, or to better test it and/or replace it... the darn thing is REALLY hard to get to though, two A/C pipes and the power steering pipe all come right in the way of it. The only other thing I can think is to 'assume' that the dealer maybe lied and I should go ahead and replace the O2 sensor... damn things are PRICEY though and I dont want to buy one for nothing and find out they really did replace it originally.... especially O2's cant be returned. Ah well... guess I'll have to do that and if that doesn't help, figure out or pay someone else to figure out how to get to the IAC valve. Thanks again Cozy Z Cole for pointing that out to me honestly I would not have thought the leaky injector code would have anything to do with these other symptoms.... I KNEW I had seen that somewhere Quote Link to comment Share on other sites More sharing options...
80LS1T Posted July 19, 2004 Share Posted July 19, 2004 Have you ever thought of taking it down to a Nissan garage? I mean think about it.... you take it in, they charge you 1 hour of diagnostics, you let them fix it, then when that doesnt fix the problem you can keep taking it back and they will have to keep trying to fix it! Thats the way it works at my dealership anyways! Yeah it sucks for the auto tech who doesnt t diagnose a vehicle correctly but atleast the customer is happy! LOL Guy Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 19, 2004 Share Posted July 19, 2004 The other thing I"m thinking is... is it necessarily true that just because my voltmeter testing and the ECU's self diagnostic testing of the O2 sensor show it to be okay, does that mean it definately is? I've now read on the SE-R forum quite a few cases where the ECU gave no indication of any O2 related problems yet replacing the sensor for those folks almost always seemed to make a dramatic improvement in gas mileage and responsiveness. I've been weighing my options about taking the car somewhere but dont really want to spend any money on it just yet... I mean it's getting me around just fine, it's just got it's share of bugs.... the great thing is that ALL of the bugs I"ve encountered so far seem to be rather common... so my Sentra is perfectly normal and I didn't get a lemon The idle thing in particular seems to be a VERY common thing and there is a huge list of things suggested for how to take care of this. Kinda weird for a car with so many bugs to have such a great reputation and huge fanbase.... Well all I have left that I can try is a) replacing the O2 sensor, removing and cleaning or replacing the IAC valve (once I figure out how to get to it) and c) a full regular tuneup (air/fuel filters, spark plugs/wires/cap/rotor). Then yeah if none of that does it I'll see about taking it some place I guess. You know... I've been posting about this for well over a week now on the nissan forums and SR20DE forums and haven't gotten 1/10 of the replies I've gotten here so far... further proof that HybridZ rocks even when I'm not asking about my Z... I dont know what I'd do w/o you guys. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 20, 2004 Share Posted July 20, 2004 Well I went ahead and installed a new O2 sensor... I hope this helps.... The one I pulled out didn't look old at all... Quote Link to comment Share on other sites More sharing options...
philiow313 Posted July 21, 2004 Share Posted July 21, 2004 What is the exact wording of the Code 45 from the Haynes manual? If it says a leaking injector it might not mean externally leaking it might mean the injector is leaking internally cause that cylinder to run extra rich. Does your car have an IAC' date=' idle air control motor? If it does take it out and see if its ok. I have seen IAC's do this exact concern. If the IAC is not working all the time it will cause the car to die when you are not pressing on the gas pedal. Guy[/quote'] this is exactly what i would have said. and yes, do a full tune up. whether it fixes the problem or not youll run better for sure Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 21, 2004 Share Posted July 21, 2004 here is a list of everything I've done so far: Cleaned the throttle body (it wasn't that dirty anyways) Replaced the O2 sensor Checked the cap/rotor/plugs/wires (all were in good to very good shape, plugs and wires looked new) Checked operation of the EGR valve (it's doing exactly what it's supposed to be doing) Checked operation of the AIV (ditto) Checked voltage on the ground wire of the MAF (well within spec) Checked all my fuses (none blown... there is one fuse which sometimes blows and can cause rough running problems) Adjusted idle (air bypass screw on the IAC) This one didn't go the way the Haynes or FSM said... I need to remove it somehow Checked air filter (was only slightly dirty) Adjusted timing to 17 degrees BTDC Things I have left to do Replace fuel filter (though I'm guessing by the condition of the other tune up items that this has also been recently replaced... since I can't verfiy that I'll do it anyways. Remove and clean the inside of the IAC Check adjustment of TPS That's every suggestion I could find on all the SE-R related forums as to how to fix these problems... once I do the last three I'll have none left and will be seriously stumped if it doesn't improve. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 21, 2004 Share Posted July 21, 2004 De Ja Vu? Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 22, 2004 Share Posted July 22, 2004 Negative... my Z has never done anything like this before, so there. really, compared to the problems the Z has had, this is NOTHING... all we're talking is an erratic idle and a stupid computer code (which hasn't come back in over a week now... maybe I finally fixed it?)... The car has 144k miles, you can't expect NOTHING to be wrong with it. Other than this the car runs great and is saving me money as well as greatly prolonging the life of my Z... from driving 250 miles a week on it to 50 miles a week... damn Z will last forever now or at least until the common man can't buy gasoline anymore. Anyways why you keep getting on me about getting a second car? YOU have a daily driver.... do you drive your Z every day?? Really wondering how you're having so much fun with this. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 22, 2004 Share Posted July 22, 2004 Just ribbin man.... Quote Link to comment Share on other sites More sharing options...
TOMAHAWKZ Posted July 22, 2004 Share Posted July 22, 2004 your o2 sensor probably fixed your problem but only temporarily. I had a senta with the same problem and it drove me nuts, set the same fault code as yours, anyway I talked to a guy at the parts store and he told me it was most likely my #4 injector leaking internally and wreaking havoc with the rest of the sensors. he told me its a common item on the nissans with 4 bangers in them something about it getting hotter then the rest and when it heats up the plunger in the injector starts sticking if i can remember correctly. i replaced the #4 injector at his suggestion and the problem went away. would have kept the car but then the a/c compressor took a dump and i didnt want to sink any more money into it. great commuter car kinda fun to drive too.. good luck Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted July 23, 2004 Share Posted July 23, 2004 LOL another common problem it seems... think my A/C compressor went out... Doesn't matter much to me as I work graveyard shift so drive at night and early morning... if I need to do errands during the day (95+ degrees here lately) I just hop in my wifes car with ice cold A/C About the injector leak... well I have looked at them and again no sign of leaks externally, and I pulled the spark plugs the other day and they were all evenly colored, so no sign of leaking into the cylinder. According to a nissan technical service bulletin the "leaky injector" code is more commonly caused by an improperly grounded MAF... but I checked the voltage of the ground and it checked out. I'm thinking I"m going to reground it anyways just to be sure. Well... going on over a week and a full tank of gas since having any error codes... Quote Link to comment Share on other sites More sharing options...
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