Electronic Distributor Upgrade - Low RPM/Load Misfires

[john510]

Check the oil in the SU's.

[racerx]

"And are the 2 front can lives pointing at 10 and 2 o'clock?"

translation:

And are the 2 front cam lobes pointing at 10 and 2 o'clock?

 

A matchbox distributor can run a points coil, with a ballast resistor, and plugs at normal points gap.

Run a wire from the distributor body to one of the front bolts between the cylinder head, and the timing chain cover.

[racerx]

Meant 2 front cam lobes.

[datzenmike]

So I upgraded my old points distributor to an electronic distributor.  I had a lot of trouble with it due to not having the correct pedestal.  I flipped the one on the car and got it to mount with the ignition module away from the header.  I am now at the point that it starts, runs, and drives; but I'm getting a stuttering misfire when putting the car under load at lower RPMs.  When I time it out at idle, it's sitting at 12 BTDC.  When I run the revs to around 3k it's showing right at 20* advance.  This is all with the vacuum advance attached.  All the plugs wires seem to be on tight and the coil wires are tight as well.

 

Here is what I have for timing marks.  I'm using the hot pink one as the TDC mark.  So to set the engine at 12* BTDC I am putting 12* advance on my timing light and then lining it up with the pointer.

 

 

 

If it runs, and you can set 12 BTDC then the cam, dizzy and rotor position is irrelevant. It RUNS. 

 

 

 

Switch to proper NGK plugs and try. If running a matchbox, but with points coil and ballast you MUST run 0.032 plug gap.

 

If you are checking the ignition advance at 3K then it can't be under load but just revved up. You say the vacuum advance is connected but at 3K no load, there would be ported vacuum because the throttle plate is barely open. Static timing 12, plus mechanical 20, is 32 which sounds about right, (if the cylinders were filled at wide open throttle) but where is the vacuum advance? Surely it would be 35 or 38 maybe even higher. Take the distributor cap off and suck on the vacuum advance hose. You should see the rotor turn clockwise and hold till the suction is released. If not moving this isn't right. Does the hose have a hole in it.

 

Stutter between 2-3K under load. Carb(s) may be going lean, pull choke out in ever increasing amounts to make mixture richer. Does this fix the problem?

[BrandonS]

Thanks for all the suggestions.  I went back out this morning and got it working 99.98%.  I first turned it on and tuned the carbs up quick; really I think they just went back to where they were set before I messed with them yesterday.  The coil was also making an arching, clicking sound so I put the new coil I had back in.  Finally, I pushed the distributor more advanced.  It's now around 14-15* BTDC.  I tried to put it back down to 12* BTDC, but the studdering problem comes back so I think that's what it was. I do, however, think the car still wants another degree or two of timing, but adjustment on my pedestal is maxed out.  I e-mailed California Datsun who makes adapter plates for points pedestal to e-dizzy to see if theirs would work with mine; unless someone has a pedestal and bracket they'd be willing to sell/send me.  

 

So what I think is going on is that the first timing mark is actually 5* retarded, second mark is TDC, and third mark is 5* advanced.  This would go in line with the car wanting 12* BTDC at idle.  If I add another 2* advance, I'll show 16-17* BTDC at idle on that first mark.  If that first mark is actually 5* retarded that would give me 11-12* BTDC. on the second 0*/TDC mark.  Oh and at 3800-3900 RPM I was showing 40* BTDC, so subtract 5 and I'm looking at 35* all in, which I think I've seen 32-36* recommended by people.

 

With all that said, I've never felt the car run like this before!  It actually pulls now above 4k, it use to always die off around there.  I knew when I bought the car the points dizzy I know needed a new rotor/cap, and probably points.  This was a good "tune up" for sure.

 

This is where the adjustments are at now.  As you can see, it doesn't give me any more adjustment for advancing anything.  I've tried moving the plug wires over one spot counter clock wise, but it shoves the ignition control module and advance into the exhaust manifold heat shield and they'd get cooked.

 

This is what I e-mailed California Datsun about...

http://www.ebay.com/itm/Datsun-510-620-280Z-E1280-Electronic-Distributor-Timing-Plate-Bracket-Mount-NEW-/152643838457?vxp=mtr&hash=item238a4821f9

[racerx]

Glad to hear you got it running properly. Did u ever look too see where you're rotor was pointing and 2 front cam lobes when you have it at tdc.?

[BrandonS]

Glad to hear you got it running properly. Did u ever look too see where you're rotor was pointing and 2 front cam lobes when you have it at tdc.?

 

Yea I had the 2 cam lobe sitting at 10 and 2 with the crank pulley on that first mark.  Then I picked where the rotor was for the #1 wire. 

[racerx]

Good

[BrandonS]

Oh does anyone have a recommendation or part number for a coil that will allow me to ditch the ballast resistor.  I originally intended to do that, but bought the wrong part number coil apparently.

[racerx]

your first, red, is 5 retarded, second mark is 0 or tdc, which means that should line up when at tdc your spark plug #1 shoud be lined up w your rotor and front cam lobes should be at 10 and 2 o'clock, yes?

 

Yea I had the 2 cam lobe sitting at 10 and 2 with the crank pulley on that first mark. Then I picked where the rotor was for the #1 wire.

[BrandonS]

I was reading online that the first mark was TDC so I was treating it as such. I believe what you are saying is true and that the second mark is TDC. So my problems where because I was timing the ignition 5 degrees off each time.  

[racerx]

Yes sounds like it. Combined with the coil issue. Glad you got it going.

[BrandonS]

So California Datsun got back to me and said that their adapter plate won't work/fix my issue.  

[docbainey]

Length the slot in the plate so it moves farther,

[DanielC]

Usually there are two bolts on the timing plate between the distributor pedestal, and the distributor body.  The obvious bolt going down through the plate into the pedestal, and there is a second bolt going up through the plate into the distributor body, under the distributor body.

The combined adjustment with both bolts is more than the amount of timing change by dropping the oil pump, and turning the distributor drive spindle one tooth on the driven gear.

You do not need to spend 40 dollars on a special timing plate!

 

If you were in the USA I would just tell you to go to a junkyard, and get a stock OEM ignition coil from just about any Nissan in the junkyard with electronic ignition.  Nissan OEM, and probably just about any manufacturer of automobiles makes ignition coils of at least comparable quality as the fancy chrome, or finned painted aftermarket coils. 

[racerx]

Could not have said it better/\

[G-Duax]

As far as a coil, I've been running a Crane PS91 for years, no resistor.

So I don't think it cares what it's firing, just as long as it wasn't some odd-ball meant for a CD ignition.

[Lockleaf]

You can just order a coil from any early 80s Datsun with electronic ignition and install that.

[datzenmike]

EI coils began on all Nissans for the '78 model year. With the exception of some California spec vehicles that were a year or two earlier.

[banzai510(hainz)]

if motor runs fine at higher RPM then its not the coil(in General)

[racerx]

I think the issue was that it was not timed properly, retarded by 5 degrees? You can also ohm out the coil before buying one. Been awhile since I tested one, YouTube it and save some money.

[hang_510]

 

You can just order a coil from any early 80s Datsun with electronic ignition and install that.

79 200SX is what ya tell the person behind the counter

[distributorguy]

There is a 19 degree position difference between the points and the EI pedestal and clamp bracket.  Just cut yours and put a fender washer on the bolt to clamp it in place.  It should give you the adjustment you need.  

 

Keep pushing timing until you go too far.  Depending on what parts Cardone used out of the pile,  there's no telling what your advance curve is or what your timing should be set at.  You need to figure that out.  They also tend to install their own replacement electronics (that look kind of original) and they have issues.  Many times they rub on the shaft and screw up the advance curve.  A 1.5 Ohm coil or a .8/9 Ohm coil will both work but you MUST open your plug gap to .040 - .045".  There's so much overlap in NGK heat ranges that running 6's or 7's won't matter.  I'd stay with the hotter 6s for a street car with lower compression.  

[datzenmike]

I think the 0.8 to 1.0 ohm EI coil will give the higher output for the larger plug gap. If you use the 1.5ohm points coil you have to also run the 1.5 ohm points ballast and the output won't be high enough to fire the 0.040" plug gap.

[distributorguy]

Sure it will.  The coil will just run a little warmer.