Like i said, my 87 Max 3.0L 6-cyl died when I was on my way to school today, I was going approx 30mph, straight line, and it just all of a sudden cut out, no sputter or anything, just died.

I took off the intake pipe hose at the intake manifold and sprayed carb cleaner in there and cranked it @ same time, didnt attempt to start, just cranks rapidly so i guess its getting fuel although i didnt pull a plug to check. Then I put a spare spark plug in a plug wire and grounded it and it wouldnt spark. I replaced the coil and it still doesnt work. I checked the code and I get a code 21, which is for the primary coil or something if i remember correctly. I also get a code 41 for the fuel temp sensor or some crap, but i dont think thats causing it not to start, cause the wire was loose and i cut it off and fixed that...

Shouldn't I be able to leave the plug wire hooked up to the coil and pull it off from the distributor cap, put a plug in it, ground it, and get it to fire? or does that only work for the other plug wires on the distributor cap? I don't get fire.

Also, does anyone have any info or know where i can get more info on checking for 12vots on the coil and stuff, its a new coil so i now need to see if the OEM wiring shorted out or something, but the Hayes manual doesnt help much..

All I saw is that from the book the harness has 4 wires, #1(Blue) which is top left(harness connector on top) is supposed to have 12v w/ ignition on on position, but mine doesnt, but #2 (top right) had 12v(black/white color)

Any help is much appreciated,

 

I would just use the spare plug to spark plug wire routine. I just did that on my friend's Acura, he needed a new fuel pump.$$$$$$

Have you made sure the timing belt is not broken? See if the rotor rotates as you turn the engine over. Hope it does.

Sounds like your getting power to that connector. B/W should have 12vdc, B is the ground, the other 2 L goes to pin 3 & 5 of the ECCM.

If that belt is good, move on to checking the Input Signal from the ECCM. You will need a logic probe to do that. The Power transistor can be checked and then the wiring harness to the ECCM.

The factory service manual has the procedure. If you don't have that post your e-mail and I'll try and scan the 2 pages for you.

Good Luck

Al

 

You might want to double check your getting fuel also. My dad ran into a problem his 78 320i, where the fuel filter was so clogged, no fuel was getting by. Like Al said, check to make sure you didn't break a timing belt. That can be a big problem if it did. Though the good part was you weren't going that fast, so if it did break, it probably didn't do too much damage.

S

 

Well, I sprayed some carb cleaner in the intake manifold while i cranked it over, and it didnt try to start, so thats when I figured it wasnt fuel. When I feel better(got a damn stomach bug), I will crank the engine and pull a plug and see if its wet, but after I grounded a plug and saw it wasnt sparking, thats what I have been working on since then...

I didnt know if there was any fuses I should check or relays, I checked the ones under the steeringwheel, and i checked like the 4 along the driveside engine bay, the only one i found for ignition was a loop through(just a wire looped), I have a Hayes service manual but its in a million pages(fell apart) so it doesnt really help. If you can post pics or email me at BrickardIUS@aol.com, I'd much appreciate it.

I will check the tbelt too. This car has never broke down since we've had it(since 87), other than an alt going bad, so i dont know what the problem is. :-(

 

When you plugged your spare plug in, and grounded it, did you plug it straight to the coil? if not, it could be either the cap , rotor, or the distrib itself. If so, double check the coil wire, and make sure the coil is getting proper fire. The coil actually has another peice to it, also...i don't have access to my book, and can't remember what it's for, but that could play a part in all of this, as well.

 

Yeah, I tried it from the coil too and still no spark :-( And even with a new coil no spark... so I dont know what the thing under the coil is called or what it does, i guess its like a modern day ignition control module or something, i dunno, but maby its that, or maby a fuse or relay... Its just wierd that all of a sudden it died... I'd say it burnt a wire or something, but then again its been fine for 15 years, hehe... plus i only got a mile down the road before it died so it wasnt even warm yet..

 

Double check all the wires feeding the coil. Also, I found it listed...the other device is the power transistor for the coil. It feeds the power to the coil, to produce the spark.

Here is Chilton's procedure for testing:

Disconnect the coil/transistor assembly electrical harness.

Use an OHMmeter, sett to the lowest setting (about 1.0 ohms)

Using the diagram below, test with the following:

a. + probe on term 2 and - on term 3 - continuity should exist
b. + probe on term 2 and - on term 4 - continuity should exist
c. + probe on term 3 and - on term 4 - continuity should exist

If any of these rpobes fail, replace the transistor.

Use this diagram:

i-i < - this is the clip on the harness end.
[1][3]
[2][4]

I hope this helps...

 

Well, I did what you said above and got continuity on a. b. and c. so i guess the power transistor is good... its still not getting spark though, so how would i test to see if the coil is getting a reference signal or what have you... I dont delve too deep in this wiring stuff usually, can i hook a 12v test light up to one of the 4 wires and ground it to see if its getting a signal?

Also, just to make sure, i dont have to have the coil installed on the car for it to get a ground or anything do i? cause i have theis new coil just sitting there plugged into the power transistor and not bolted to the metal.

 

Hey, did you get the 2 pages I scanned in your e-mail? It tells you to use a logic probe to check for the signal from the ECCM to the Power Transistor. I wouldn't use the test bulb to check for the signal. That might cause it to draw too much current thru the ECCM pin#5 and burn something up. Get the logic probe from Radio Shack.

IS that Rotor turning as you crank the engine?

Al

 

Yeah, thanks for the scans. I have been following the main stuff i'm pretty sure i knew how to do correctly.

a. The first thing is to see with the ignition on whether your getting 12v, and it does.

b. is to check power transistor w/ circuit tester. when i follow these instructions out of the book it fails. your supposed to test from top side, and it shows the order as.. look at picture, i pointed out which tests failed, and i believe one or the other can fail but not both since it says OR, but as you can see one of the tests failed to show continuity both ways... does that mean this thing is bad, or is that picture of the harness numbers wrong? what is the likelyhood of this thing going bad out of the blue?

]

BTW, the rotor does spin correctly.

Also, I am reading it correctly that I need both harnesses on the power transistor unplugged right? I dont need to leave it plugged into the coil, right? I get different results if its plugged in or not plugged in... but if its plugged in it fails the first test... I am using a Fluke 73 III, on some tests for contunuity it will keep a constant beep, on others it will beep briefly and wont beep again unless i move one of the probes off and put it back on...

Thanks for all the help and any further help you all can give me

 

Did anyone mention fuel pump? Even if you have a full tank of gas and the pump fails, that it it. You won't start it until you replace the fuel pump. Nissan forgot to change mines when they changed the injectors. A few weeks later, I was back, with car in tow. The fuel pump had failed!

 

Yep, the more I look at the picture of the harness numbers I think it is wrong and mislabeled. That sure making it confusing.

You are right about removing both harnesses, coil and transistor, before testing the power transistor. You can also test the coil by itself.

1 to 2 should be about 1 ohm, 1 to 3 should read 10k ohms. #3 being the high voltage (spark) terminal. Doesn't matter which probe is +/-.

Here's a link on testing transistors, this would be the best way to check it.

http://www.elexp.com/t_test.htm

http://www.anatekcorp.com/qdmmvom.htm

Al

 

Well, I didnt get much out of those articles, well, I did, but not much I applied to testing this thing :-(... So you think the numbering was odd too, huh? Well, the Chilton's test above a couple posts ^ I swear it passed all 3 the other day when I did it, but now it passes 1 and fails two of the tests... So I dont know if I have been just fxckin' around w/ this thing too much and ruined it, hehe, but I guess since it fails the FSM tests and the Chilton's now I will have to replace it reguardless... Although no one seems to carry this power transistor in stock... Wherever I find one, I am gonna test it w/ my Fluke just like i tested the old one and see if it passes correctly, if it does, I guess then I need it, huh? and if it does what mine does, then I guess I'll move onto something else...

 

I don't know if this helps too much but there should be a procedure for testing the coil in the haynes manual with an ohmmeter. also, if nobody else mentioned it, there are 2 fuses to check, one for the fuel pump and one that says engine control or something, I think they're right next to each other. and if available, an inductive timing light clipped around the coil/plug wires is a good way to check for a spark without removing the plugs. Hold in the trigger while someone cranks the engine. check the coil wire first. If you get a bright strobe-like flash, the coil is fine.

 

The coil is not getting anything, but the harness is getting 12v w/ the ignition on, it is a new coil, it tests fine, the old one tested close to borderline on FSM specs, so i got a new one while i was at it, and now i have tested the power transistor and it has failed, so i am going to replace that and cross my fingers, i have checked the fuses in the fusebox and they are fine, havent checked any relays or fuses in the engine bay cause i dont know what is what, only checked the "fuse" for the ignition switch in the engint bay, but its just a loop and it gets continuity... the harness ground shows to be good also, so I guess i really need a logic probe to see if the ecu is sending a pulse. Any way i can safely use my Fluke73III to read for the pulse?

 

yeah, Flukes are really good meters, but any digital multimeter will work. I'm generally good with automotive electrical systems but I don't know much else about the ignition system, and it was hard for me to follow along with the entire post. the fuses under the hood won't have anything to do with the car starting.

I wish I could be of more help.

 

Well, we know he's not getting spark at all to the cylinders. Therefore, whether he's getting fuel or not, he won't crank.

This would be easiesr to diagnose, I would think, than when my distributor went out. Changed cap & rotor, and it started running like $hit. Put the old ones back on, with same results. Checked the new ones, and found the rotor had made contact with one of the contacts inside the cap...took a week, and lots of long distance calls to the guy I bought it from (A Nissan specialist, and Maxima enthuesist), and the nearest dealership service center (with was 2 hours away), to discover it was the distrib. When I took it out, the thrust washer that normally keeps everything tight was GONE. No metal shavings, no nothing...just GONE! So the dist. shaft had about a 1/3" of vertical play. So, when the engine was running, the shaft would rise with cams rotation, retarding the engine so badly that it was literally running on three cyliders, basically in "Limp Home Mode".

With a $200+ distributor, that was easily the most expensive tune up I've ever done, or had done...whew!

 

Well, I got the power transistor today, but it had a different plug on the coil side, so they gave me the coil that fits it, I guess its similar, it showed up under 87 max 3L, so i plugged the new stuff into the OEM harness and tried to start it and still, no spark.

So I guess I need to probe the ECM for a pulse signal, how do I do that? Which wire is it and what kind of equiptment can I use to view the pulse. I have a Fluke 73III, but I dont know much about it.

 

This is shot in the dark, but if the power transitor needs a pulse from the ECU, could it also be possible crank angle sensor would cause this issue? Dunno...

S

 

Well, I don't know... I know on newer cars thats the case, but I haven't worked on this engine....much. I have just been following the steps in the manual, basically, if you diagnose no spark, check rotor rotation & obvious signs of wear, verify power to the coil harness, check resistance values of the coil pack, test the power transistor for continuity, verify a good engine ground and the harness's engine ground, and then check for a pulse signal, after that it just ends the section of not getting an ignition signal.

So, does anyone have any objections to me using a 12v LED to check at the ECM for a pulse? What range should I find if I were to use a meter? and is the pulse enough to light up my LED?

 

By all means, check your ECM for a ground pulse. I don't have the spec on that test, so I can't tell you how to do it, but it's a very good possibility.

As for Maximase86's question about the Crank Angle Sensor, that's also a good possibility. This unit is integrated into the distributor. Yes, some parts houses carry just the sensor, but it has to be aligned to the distrib. It's easier to just buy a new one, albiet, about twice the price. I got a huge discount on mine, due to the problems I had when my distrib bit the dust, but the average going price for a rebuilt is about $200, give or take. You may be able to pick one up at a bone yard for cheap, but there's no garanty that it'll be any better than what you have.

 

Just an afterthought, but don't forget to have your timing and idle adjusted properly, if you end up replacing the distributor.

 

I think you have a bad crank angle sensor. It is in the distributor. The main symptom for a bad CAS is not spark at the coil. I'd just get one at a boneyard. You are looking at buying a whole distributor at Nissan to get one, which is going to be a major chunk out of your wallet.

 

Would I get a code on the ECM for a bad/faulty crank angle sensor? If I do have a bad crank angle sensor, would it just die all of a sudden and not run again? I guess it would if it totally failed.

With a bad crank angle sensor, would it not allow the ECM to send its pulse signal to the ECM coil wire?

I setup an appointment to PAY to have my car looked at next wednesday, so I am just trying to do whatever I can up until then to fix it, but I hate to buy a new or used whole distributor if its a possibility its not that... ya know?

 

A used distributor is way, way cheaper than paying somebody to "look at" your car. Plus you will have a spare if it is not the problem. It will be the problem sometime. A bad CAS will stop your engine with no noise or fuss, it will just stop working. A bad power transistor will stop your engine intermittently when the transistor over heats, and let it run again after a few minutes or hours cool off period, although it can just stop and not work again, too.

Code 11, one red and one green denotes CAS circuit fault.

 

Well, maby it is the CAS, I guess if the CAS was bad, it wouldnt let the ECCM send a pulse to the coil, and that would be why its not firing... makes sense..

there is continuity from the wires from the ECCM to the crank angle sensor harness
6. the rotor spins correctly

I removed the distributor because I think I might get one from a junkyard for 40 bucks and try that, but I don't know how to align the teeth and stuff to know how to reinstall it correctly. Any ideas?

 

Well, when you removed the old distrib., did you mark the orientation of the rotor versus the old distrib, or the block itself? If not, and if the engine isn't at TDC, you're not going to be able to reinstall either the old or the new, without finding TDC on the engine.