1984 Datsun/nissan 4x4, Z24 engine. About 1 year ago, I pull up to red light, and I watch my tachometer sputter down/die. That's weird, turn truck off/back on, tachometer jumps, but dies, engine is running fine. I take instrument cluster apart, speedo cable has been leaking gear oil from xmission all over everything on backside of cluster. Replaced speedo cable, and completely tear apart ALL TAPED UP wiring harnesses, and remove gear oil. Turn signal flasher and 4way hazard flasher full of gear oil, repaired both. Replace tachometer, with 1 from junkyard, no change. I change terminator/resistor for distributor/coils, no change.

I have original/like new 1984 service manual from nissan + hanynes and clymer manuals. Hell I can live without a Tach, so I have lived without tach for a year. Fast forward 2 days ago, I go to check the timing. No fire out of 1 of the 2 coils. Confirmed with timing light. I test/measure both coils according to manual, both coils test good/same/identical. With the good coil, I switch coil wire with the bad coil, and change which 4 plugs were firing. IE I can make 4 plugs fire on the intake side, kill engine, switch wire to distributor, and get the 4 plugs to fire on the exhaust side. So 1 of the coils is working fine, while the other appears to have no input, thus no output

June 2009, 10 days before I bought it, previous owner bought remanufactured distributor. Reason given was "no fire". I found the old receipt in glove box. SO.....anybody out there ever run into this problem? Any help/ideas appreciated. Thank you.

Something else weird. Same problem. 6 months ago, I see little green plastic bits, in my floorboard carpet. AND I have no brakelights. I figured out the little plastic stopper broke apart, and I replace with small bolt and nut and locktite. Brake lights work fine now. 2 weeks ago, again, I find little green plastic bits in carpet. HHGGggmmm, ok, look at clutch pedal, clutch pedal is missing the little stopper. Ok, I replace stopper with bolt and nut and locktite. Note this time, I only find 1 tiny piece of green plastic, not the whole stopper. With the brake lights, I found all bits of the green stopper, and reconstructed it, and put with all my other little spare parts. THIS TIME I only find 1 little piece of green plastic, not the whole thing. OK.

So i put in nut and bolt in clutch pedal. I note that with or WITHOUT the nut and bolt, does not matter as far as cranking the truck. The clutch pedal has a switch there, and you would figure, the truck wouldn't crank, unless you depress the clutch-to keep truck from starting in gear-but, it doesn't matter. Truck cranks regardless of whether that switch is depressed. HERE IS THE WEIRD PART- I am cruising, in ANY gear, 1,2,3,4th gear doesn't matter,,when I get up to about 3 K rpm (no tach going by sound) everything is fine going up-speeding up---now I STOMP THE GAS to get maximum acceleration, and truck bogs down, like it's dying. Barely let off gas, truck comes back to life, all is well.

I will put it this way-lets say I pull out in front of someone in traffic. I notice I'm not going fast enough, car coming up quick behind me. I am in 2nd gear, at about 60% throttle. So I put accelerator all the way to the floor. Up to about 90% of that throttle, I am speeding up fixing to change to 3rd.THEN, out of nowhere, the truck goes "bbbbrrrr"- like I am completely backing off. But I'm not, I am trying to speed up. I barely let off gas pedal, and BOOM, truck picks up again. I switch to 3rd.Eventually same problem. I am speeding up, all is well, with gas pedal depressed about 80% of the way to the floor. I press gas pedal to about 90% to the floor. Speeding up, all is good. I go all way to the floor, and "BBBBrrrrrrrr" engine is shutting down like it is being governed, like a diesel. The moment I let off gas pedal-boom-all the power I need is there.

I get home, and take nut and bolt out of clutch pedal, and now all is fine again. 90%-100% gas pedal is there, pure acceleration. Truck doesn't do the "BBBrrrrr" thing. Ok, I don't believe/understand this crap, I put nut and bolt back in clutch pedal/making my own little stopper, and sure enough, I lose acceleration 90%-100% of gas pedal being pressed down. Come back home , remove nut and bolt again. Thats where I am today. Weird crap going on here. Thank you for your time and reading this. I look forward to responses. I am a mechanic and Electronic technician. Bad grammar.

EDIT--- truck is pure stock, and passed emissions a year ago, no vacuum leaks, All equipment is there.

Summary, 1 of 2 coils has no input or output. Tachometer is dead. Clutch pedal electronics is possessed by the Devil.

Not to sound insulting if you have already, but it may be worth checking your fuse box. I was looking at my own fuse box diagram just today, and noticed that the first 10 amp fuse on the bottom runs only #1 ignition coil. (Ours should be the same, 85 model fuse box). The second one up, I think a 15 amp, runs the second coil, fuel pump, and others. Just worth a quick check.

And I have no idea about the clutch pedal. The 90-100 percent thing almost reminds me of fuel filter, but if it's fine when you take the nut and bolt out, then idk?

And mine still cranks in gear, just jumps. lol. And I have no trouble cranking in neutral w/o clutch in.

EDIT: I mean the fuse box in the cab, near your clutch pedal.

http://imgur.com/dFZVF That fuse thing, I just checked that 1 hour ago, LOL. I've been studying on my problem for a week now/going over diagrams/reading, so yea, the fuses there are good. Fuel filter is new along with all small hoses there on bottom end cause they were dry rotted. I'm going to try that blue ICM relay tomorrow, that swaps with the heater relay.

ALSO WHATS YOUR IDEA ON THIS???--- I've been reading all the posts here. If you (ANYONE OUT THERE) HAD A CHOICE, would you run the 4 plugs on the intake side? or the exhaust side? I do have a choice here, cause 1 coil does work. The intake plugs are BTDC, the exhaust plugs are after TDC.

Crap,,,trying to stick image in here, can't figure it out, same with thumbnail,,,newbie here.

2 things that IT'S NOT---Fuse links off positive side of battery---litlle blue ICM relay above fuse box and on sidewall beside the battery. Swapped them 2 out with a couple spares I had laying around. The voltages on the coils goes like this (((The 1 coil that runs the intake spark plugs is the coil that is working. it has 12 volts on pos. side, and 8.5 volts neg. side.)))[[[[[the dead coil that runs spark plugs on exhaust side had 12 volts on pos. and neg. terminals]]]

Later on that same day...so I took the little positive and negative wires from both coils and swapped them. The once dead coil is fine. The coil that had no output going to the spark plugs on the exhaust side, is working with the pos. and neg. wires from the intake side coil.

Try bridging the positive from the working coil and see if that works. If not change all the wiring on the coils not just the coil wire. If there is no change then you will have to change the coil.

Both coils test good with ohmmeter, And I did swap out the wires. And the coil wire. Coil fires when it's on 1 set of + and - wires. So I take those + and - wires and put them on INOP coil. Now, that INOP coil works fine, but the OTHER coil now is dead/no output.

So, there are 2 coils here. Wiring to 1st coil DOES FIRE intake side of spark plugs.

Wiring to the 2nd coil (that run the 4 spark plugs on exhaust side of engine) THAT + and - has 12volts, to each terminal--- Positive and negative---power is there,,,,But coil will not do what its supposed to do..IE collapse magnetic field and stick it to distro.

Both coils work,, but only 1 coil works/test good/fire/ARE FINE when the engine is running.

UPDATE UPDATE UPDATE---WEDNESDAY AFTERNOON.

I jumpered the 2 coils together, NOW TACH WORKS and both coils are firing. I jumped + to + and - to - on the coils and BAM! first thing I see is the tachometer works and both coils are firing. With that said, I would believe now the 2 coils should be/maybe firing at the exact same time-whereas intake coil should fire 1st BTDC and exhaust coil should fire at TDC or a little after.

So,,,what the hell is my problem???? My problem is, my truck is still not fixed CORRECTLY. I'm thinking maybe Ignition coil module inside distributor is bad? I don't know. I'm looking for any comments I can get here.

In response to your previous post about them both working, but simply not firing, did you check them at all RPM's? The second coil does not fire all the time fire at all RPMs. I don't recall what the exact firing of that coil is supposed to be, however. This does not describe what the tach problem is, though.

Crap. I didn't think about that--running engine up to 3K rpm and checking to see if exhaust coil was putting out--I only checked them with timing light at idle. But, then again, now that I have jumpered them together, they are both firing at idle, and tachometer came to life. Damn I need an engineer who designed this. BTW, went to parts store website, the ICM (ignition control module) inside distro is $259. Remanufactured complete distro is $130. (comes with module and all inside). Tomorrow, or next day, I will have to put all wires back to normal, and troubleshoot the ICM inside distro.

FINAL UPDATE---It is the ICM inside distro.....TADA!

Nice.

Sweeet....

Just for info. The ecm shuts down the intake coil under full acceleration. The RPM doesn't matter, only when the accelerator is fully depressed.

Thats good info for me to know. I'm documenting this whole thread in my notes about this truck. However, this 1 was built in Canada, not for California market in April 1984. It has no ECM. Also, after jumping the coils together, I put that little stopper back in clutch pedal. Now I have no "BBBBRRRrrrrr" at full acceleration. With or without clutch pedal stopper, doesn't matter. The "shutting down during full acceleration" went away-after jumping coils. So something is still not correct, thus the Ignition control module (ICM). The ICM passed all tests, except the very last 1, so now I'm sure I need the ICM/rebuilt distro. Cheers!

Which coil is the exhaust coil and which is the intake coil? One is directly behind the headlight, and one is just above the wheel well. They are labled on my dist cap. I and E, but I wanna make sure i don't have them mixed up. Both are stock coils, and no matter if I swap out coil wires, it has no affect on driving. Reason I'm messing with this is, my truck runs great and idles great... but when I'm in 3 or 4th gear going up a hill and having to push the gass. it has a slight hesitation. very slight ... but it's there. I've checked all vac lines, fuel filter, fuel pump...fresh tune up... new plugs.. dist. cap.... and plugs... It was fine before I changed the plugs. the plugs i put in it were autolite platinum. I read some where that could be the problem and NGK's or OEM's work best in this motor. Any thought?? Thanks for the help.

Here is 1 way to tell the coils apart. By the color of the wires going to the coil, INTAKE coil = white/blue wire and brown.
EXHAUST coil = Black/white wire and red. It's cool that your distro cap is marked I and E, but mine isn't marked. I had to use my timing light. I knew only the exhaust coil was firing, because of color of the wires. So I swapped the coil wire on distro cap, and saw the Intake side was firing with my timing light. Then I switched the coil wire back to exhaust. Hang on, I'm going outside to physically check this....ok, heres how mine goes...coil behind the headlight = exhaust coil = black/white wire and red wire = GOES TO BOTTOM HOLE ON DISTRO (IE. there are 2 physical coil wire holes, and it goes to the 1 closest to the bottom of the truck.) Do me a small favor and write me back here with the answer to this question---On your distro cap, 2holes, a top and a bottom, which hole is labeled "I" and which hole is labeled "E"?

Ok. on my dist cap. The one that is closest to the front and up is the Intake coil wire, and down and back in exhaust wire. However. I did not put this dist. cap on but Could the dist cap fit either way? if so It could be upside down.I know on my 97 HB the dist cap can only go on one way. And since I went out and looked... White blue and black wire on my Intake coil, and black white and red wire is on my exhaust coil just like you said. there is no way my Cap is on upside/ backwards, cause all my wires are on in the correct order.
Broke down 3 times today... first 2 times coasted into gas station... first time put 7 gallons in it, and started up and the second time put one gallon in it. but the last time.... fuel pump went completely out, already had replacement, and since it was running, though I would check the filter on the carb.... Bad IDEA. Once I got the filter out and stuff, the little needle fell down in on top of float, and COULD NOT get those 3 phillips screws out. So I used a magnetic screwdriver and c a r e f u l l y got the needle out, THOUGHT it was back in place put it all back togather....put new pump on, turned it on... and flooding.... flooding. Luckily my Fuel pump is on a toggle switch, so just to get it home. I got it started, and drove for 7seconds with the fuel pump off, then I would switch it on for 1-2 seconds, back off, 7-8 sec. back on and so... all the 14 miles home. It worked and I got it home. Not the most redneck thing I've ever done.. but pretty close. So tomorrow I gotta get those 3 screw off to get the needle valve back in place to prevent flooding. Anyone had to take those 3 monkey tight screws out where the glass windows in the carb is? thanks for all the help.

Well, it appears between the 2 of us, we have our coils hooked up correctly. That carb thing you have going on? I am clueless.

SON OF A b**** MOTHER f*** f*** PIECE OF JUNK a** DATSUN f*** s*** DISTRIBUTOR MODULE TACHOMETER DIED AGAIN !!!!! OK then, now got that out of my system, title pretty much says it all. TACHOMETER died again today. So I assumed the ICM in the distro, crapped out, and I assumed I had only 1 (of 2) coils firing, because----THATS WHAT STARTED THIS s*** A YEAR + AGO....No, the good news is BOTH coils are firing (confirmed with timing light) but, Tachometer does not ,,tach?,,,,

I will update this after I go break something... son of a b****.

OK OK OK ,,,1ST--MY APOLOGIES TO THE MODERATORS, they really do clean up your speech for you, I was just highly upset last night. Now TACHOMETER LIVES!!! It was just a bad connection,,,carry on.