Strange distributor behaviour

[Captainnapalm]

I'm in need of help; this problem seems to defy logic.

 

I'm putting a new dizzy on my 1980 S130, manufacture date Aug/79. I have no spark. But the behaviour is puzzling.

 

With the dizzy out of the car, and connected to the factory wiring harness, turning it by hand causes the coil to fire. The same happens when using jumper leads to power the dizzy and coil, effectively isolating it from the rest of the car. Turning the dizzy makes the coil spark.

 

Now, the puzzling part is, when the dizzy is installed in the car, no spark. Both with factory harness and when it is isolated. The only solution I can think of is that the IC control module need to not be grounded; of course the dizzy is grounded since it is bolted to the block and shares the block's common ground.

 

I came to this conclusion after being shocked through the dizzy casing. My only guess is that my ground strap wasn't on good enough and -I- provided the path of least resistance.

 

Now I'm asking to draw on the knowledge of the community; has anyone else ever encountered this downright weird behavior, and does anyone have a fix for it? The dizzy and IC control module are new remanufactured units. I know manufacturing errors occur... but neither I, or an ASE mechanic of 32 years have ever seen this sort of behaviour from a distributor before.

[Jared]

is the engine actually spinning the distributor?

[woldson]

Remembering years back, that dizzy will not work with that car. Do not remember why.

Open it up and compare.

[Captainnapalm]

Yeah, the dizzy is spinning. And the dizzy has no reason to not work with the car; it was ordered for a car of that production date. I do know that parts changed after september of '80 so I got the parts for the '79 and early '80 model. Opening it up both were identical, except that the magnet in the old one is cracked, the the new one is intact.

 

the only variable between the distributor working and not working is being bolted into the car.

[roger.svoboda]

You say you got shocked thru the distributor housing which would indicate you got 5 Kv or whatever going to the plugs is. You wouldn't feel 12 volts SOOOOOOOOOOO you provided a path of lesser resistance to ground than the plug and plug wire. WERE the plugs installed or just laying on the block. are the wires good? particularly the wire from the ignitor to the top of dizzy. Only common thing going to the plugs. But I don't quite understand how you are testing the stuff. I would put it all together lay the plugs on the block and hit the starter see if you see sparkles. Do it at night in a dark spot and see if you see sparlkles where there shouldn't be sparkles. You say you are turning it by hand on the bench so where do see if anything is sparking.

[SHADY280]

when the unit is in the car, remove the little black box from the dizzy, make sure the connection to it is not touching the housing and try again,. it is possible it is grounding the little black box out to the housing of the dizzy and making no spark. also check your cap and rotor, they may have carbon trails that are grounding something when it is grounded in the car.

[Captainnapalm]

Well, I have spark now. buuut...

 

When the distributor is turned just slightly out of time, I get a good, healthy spark. But when I put the distributor in its original position, I get nothing.

 

Also, about carbon trails; This is a BRAND NEW distributor, pickup coil and IC ignition module. All items test just fine using the FSM testing procedures. It's also a stock coil, but tests just fine.

 

has anyone else had a problem like this? It's extremely perplexing. Not even my local Z guru, a man named Garland (don't know his last name) has seen this behaviour from a Z before. Everything seems to check out electrically, but it's just not working.

[woldson]

Drill a hole in the top of an old cap, and see where your alingment really is!

[Captainnapalm]

well, an update. I get fire if I pull all the spark plugs; the engine cranks at around 4k RPM at that point. running the distributor with a drill, with a snapon multi-tester, I find that the RPM needed to induce spark is almost 1000 engine RPM.

 

now I don't know how fast a Z car has to crank to start; I'm used to American cars which can crank fairly slowly to start. But I have narrowed this problem to the new distributor; It seems faulty. My spark is erratic, and the noid is erratic.

 

I update this because I had never encountered this problem. Nor has anyone else except for one person on the IETN. And he's worked for almost a year on his 78 280Z with no luck. So the infos will be here if or when someone here has the same problem out of the L28.

[S130Z]

Have you tried a different distributor? Maybe the one yo have is faulty.

[woldson]

well, an update. I get fire if I pull all the spark plugs; the engine cranks at around 4k RPM at that point. running the distributor with a drill, with a snapon multi-tester, I find that the RPM needed to induce spark is almost 1000 engine RPM.

 

now I don't know how fast a Z car has to crank to start; I'm used to American cars which can crank fairly slowly to start. But I have narrowed this problem to the new distributor; It seems faulty. My spark is erratic, and the noid is erratic.

 

I update this because I had never encountered this problem. Nor has anyone else except for one person on the IETN. And he's worked for almost a year on his 78 280Z with no luck. So the infos will be here if or when someone here has the same problem out of the L28.

 

 

Nice trouble shooting, sorry you found a faulty new one.

Rpm while cranking is below 1000. I think it is around 500.

[Captainnapalm]

No new distributor yet. Autozone takes forever to get things in. Just out of curiosity, and because I can't find my Hollander book, and I can't find anything conclusive in Search, what distributors will fit a 280zx? Both from Nissan and other makes? After having his bad luck with the stock dizzy, I might go with another make.

[Zmanco]

Just an fyi, my L28 with a stock starter cranks around 225 rpm. A gear reduction starter is even slower.

 

I don't think you need to leave the L28 family of distributors, you just have a bad unit. I believe the main differences between the various flavors used in the NA ZX (80-83) is the advance curve. Some begin the advance at lower revs and/or have less/more total advance. Sorry I don't know the specifics by year and transmission, but I know there are a few threads on this site that discuss the specifics. If there's a JY nearby you might try to pick one up and drop it in just to confirm the problem. Last one I bought was only $20 IIRC.

 

Good luck.

[Tony D]

I'm with Zmanco, the cranking disable circuit on most Aftermarket ECU's is 300rpms. You can get a fuel injected Z to idle to 400rpms without much effort.

 

Cranking to get it running is literally a 'tick' of the key to get the first cylinder to fire in an EFI car. Basically one revolution, no more than three revolutions on some aftermarket systems to pick up various sensors.

 

But on the stock system, turning the engine over with a cranking voltage at the battery above 9.6VDC will fire the engine reliably and get it running at idle speed simply by moving the engine across the firing point on the distributor.

 

Cranking speed has little to nothing to do with it in an EFI HEI equipped car. It's not a magneto which needs a set minimum rpm to work the impulse coupling and self-generate.

 

It sounds like an internal short to me---something where it's not grounded, or a wire is pinched and turning it in a set manner kills the circuit.

 

Any L-6 Distributor from the same year will work (nissan/Datsun Product)

 

I'm not sure what all this fuss is about '79' dizzies. If it's an E12-80 with a black box on the side, just about anything from any Datsun L6 will work.

 

Even on the earlier stuff (75-78 for sure) 'says' this model year only...but really the pickup and etc all work with exactly the same values, and they all mechanically physically fit. It's just a matter of getting the wires in the right plugs to work with the harness in the car. And that's not a big hurdle, really.

[Captainnapalm]

The bulk of my problem has been the lack of 280ZX's. None of the junkyards around here have them; Mine was the first 280ZX I'd seen since I was a child. But, I found a known good distributor from a 280ZX; a guy owned a 260Z with a 280ZX dizzy and was going to EDIS so he let me have the dizzy. Turns out my problem was the air gap. I haven't tried it yet, but I anticipate that this dizzy will fix my problems.