No spark-won't start- turns over freely---

[JoeKansas]

I am new to imports-so in any replies would you explain any abbreviations you throw at me, please? ECU ECM blah blah blah I have went back through 25 previous pages of posts looking for information and am about overwhelmed with abbreviations . Lots of good replies to all the questions. I am impressed with you guys. After all the reading, still didn't find exactly the right answer. Some problems sounded close, but not right on the bulls eye. 1989 Sentra, 4 cyl. crosswise mounted, automatic. Carbureted. Not sure of the exact engine type, but I think KA24DE- from what I have been reading on these posts. Could be way off. You can correct me if I need it! Not sure what the DE stands for. Worn out car, basically. Was running normally- for what that's worth. One 15° morning, so cold it would barely turn over, but wouldn't start. I haven't been working on this car recently, nor has anyone else. A 17 year old girls has it and I am trying to get her back on the road. First, going through my checklist, to see if it was a fuel problem, I put a few drops of gas down the carb- not a lot. Turn it over- no start. Pull the coil wire out of the distributor. Terrible- cap is cracked, socket is corroded, and cap is split at the coil wire hole, and wire end is about gone. I put on a new cap- used old rotor. Put on a different coil wire.Try to start it, and nothing. Pull coil wire back out of cap and hold it close to engine to see if there is any spark during cranking- none. I can hold the end of the coil wire during cranking- nothing. I took the ignition coil assembly off of the inner fender well to test it on a bench- By the way, this also held what I believe to be the ignition module~ I found a photo of a similar item on a online nissan parts store-a grey item with a 3 pronged female socket that takes a male 3 prong plug- fastend down on this bracket with two screws. Anyway, between the two prongs in the receptacle on the coil itself, I get continuity. I couldn't get any from the coil wire receptacle to anything, but I don't think that was an accurate test. I may do it again. Put probes in the male plug on the wire going to the coil, turned on the key, and had DC voltage- about 12 volts- an analog meter on a 25 v. scale. Didn't get the exact amount, was just pleased there was juice there. Turned the engine over with the probes in the plug, and all that happened was a voltage drop while the engine spun. Can't remember if I had the distributor cap on when I did this check. Anyway, I don't want to just be a parts changer, I want to find and fix this problem. I did take the rotor bug out of the dist., and the plate underneath that, and could see what looks like finely slotted "diffuser plate" to make and break a light beam to make ignition pulses??? Is that in the ball park. The set of wires coming out of the distributor housing haven't been disturbed, and I can't really tell where they go- except along the engine under the intake manifold. So, is there some relay, fuse, or something that controls the power going to the coil. I don't want to go buy a non returnable coil to try and fail to remedy the problem, but I may have to. I will stay tuned. I have clicked the option of "email me all replies to this topic" so I don't miss anything.

[s13sr20chris]

that engine is an e16. silly question but did you make sure the cam is turning? i have seen a few of those cars eat coils and a few eat engine control modules(ecm) but i have seen many eat distributors. distributor usually fails due to heat and works fine when cool. so its not likely to be your issue. i wish i had a wiring diagram to help you troubleshoot with but i dont. i will tell you that your understanding of the distributor is correct. it controls the operation of the coil/ignition module the way the points used to do on old cars. i have seen very many bad coils that test good with a multimeter but fail to provide a spark. my freind you need another sentra to mess with.

[JoeKansas]

I have a few questions: (1). Can this car produce trouble codes- where do they show up and how can I read them. (2). Where does the wire-loom from the distributor body go to? I think this is where my troubles start. Somehow or other, I am not getting any signal from the distributor to the coil/ign. module to tell it to do it's thing. Read on........... Took the coil/ignition module off of my dead vehicle to another sentra ('90) and installed it on that car, and the car fired right up. Not a problem with those two items, evidently. And, yes, my distributor shaft is rotating. One thing I didn't put in my original post was the presence of a bit of oil in the distributor housing. Not thick, but it was there. I didn't really notice any on that rotating perforated wheel in the dist., just mainly around the insides of the dist. housing and on the lower portion of the inside of the distributor cap. After I brought the coil assembly back and put it on the car, I took the cap off the dist., the inside plate and rubber inserts out, and exposed the perforated wheel and the black plastic part it revolves through. Then I took "formula 409" everyday ordinary kitchen spray degreaser and sprayed all the insides of the dist. to try and remove any trace of oil and dirt. I was going to spray "brake parts cleaner" in there, but didn't want it to attack any plastic parts and ruin them by accident. Did that, then blew it out with air. Reassembled all of that, and still no spark. I also removed all plastic bodied relays, energized them to check each set of contacts. They are all ok. I checked the fusible link to the ignition switch on the drivers side fender, the fuse in front of the drivers knee which was "engine control". I found no other fuses or fusible links. I unwound one of the wire looms which came from the coil/ign. module and found a couple of interesting things. They looked like plug in fuse caps or something like that. One was a resistor and the other was a capacitor. Both were good. I just plugged them back into their respective wires and went on.......... I am lost, and about to either buy a chiltons book or take this to a nissan man..........

[JoeKansas]

What does it look like- this ECM I notice a lot of plugs and wiring harnesses under the breather.

[s13sr20chris]

ok, let me be sure of all this.are you sure it is carbuerated? does it have the plastic see through fuel filter or a metal one? sometime throttle body fuel injection looks like a carbuerator.there is one component between the dist and coil/ignitor. that is the ecm. i believe it is under one of the seats or the dash. of course there is a bunch of wiring too.

[JoeKansas]

Well, No, I am not positive that it's carb. equipped- I was just assuming that the air filter was setting on a carburetor throat. I haven't seen the fuel filter.........maybe it is throttle body injected. Anyway, since it's not a fuel problem, I didn't pay that much attention to that area. I got another distributor from the junkyard, and tried it- no spark. took it back and got money back- good guys there......... I did find the ECM under the passenger seat, and wiggled the wire terminals a bit, tried to start the car, and no dice.

WISH I COULD FIGURE OUT HOW TO MAKE THE CAR SHOW TROUBLE CODES- I HAVE A CHART WITH THE CODE EXPLANATIONS....

Then I unplugged each of them and re-inserted them. No difference. would I have caused the ECM damage by unplugging it while the battery was still all connected? Thought about that too late.Don't you reckon that this thing is the only thing left that could be causing the problem? I rather doubt that someone has kicked a wire loose or anything like that- no one has been messing with the car until I started "trouble shooting" What are the odds of a ECM going bad, anyway? I see an ECM for this model vehicle for 8$ on ebay right now. Says it came from a running car. Our local nissan expert says he can get the car in Monday if I don't have it running by then. This car started out $400 for the car- then $100 for new exhaust- all the way back, $70 for two new tires at Walmart, and now $30 and hour for this fellow to look for an electrical problem. And this engine leaks oil like a seive out the front by the oil pump. I think we are beating a dead horse, but she needs something to drive........... I thank you for all the replies, though.

[JoeKansas]

...and I got 5 trouble codes. These codes are from "troublecodes.net" To refresh you, this is an '89 sentra. Fuel pump will run, engine turns over, distributor rotor spins, coil and ignition module are ok (tried them on another car) -just no spark in my car. ECM was under passenger seat. When finished I didn't clear trouble codes. I let the ecm run thru the codes a couple of times to be sure I got them all right. I am positive I didn't get any of them mixed up- but it sure would have been easy to mistake 12 and 21- with 21 being "ignition signal". Now, I am starting to doubt myself......but here they are.

12 -air flow meter/MAF sensor23 -idle switch off (on/off diagnosis)34 -knock sensor45 -injector leak51 -injector circuit

I don't recognize anything there that would keep me from getting ingition spark. But, as far as 12 and 23............where is the MAF sensor and does it only perform a funtion when the engine is running, and what would the idle switch do. I am going to post this under another thread, and maybe start a new one also, so more chances of it getting viewed and answered.

[s13sr20chris]

i was going to reccomend opening up the ecm to look for corrosion but if you can get for $8 then i think you should just to try.i really wish i had a wiring diagram for you so we could do a proper pin test.

[JoeKansas]

I was in the process of checking for bad grounds. None, all good. I was about to put a test probe into the coil plug and then the ignition module plug, when I came across a broke wire that was down in the taped up part of the wire loom that feeds those two items. About 3 inches down from the plug itself. I stripped the insulation off of the two ends, clipped a jumper on the two bare ends, and turned the key.

Started right up......So, all is well in Kansas and the girl has driven off in her car. I have learned more about electronic ignition than I ever thought I would need to know, and most of it I learned here. Thanks.........

[s13sr20chris]

no prob. if i had a daggone fsm for that car i could have pointed you in that direction much sooner. oh well. glad it worked out bro.