720 l20b dizzy wiring plz help

[Kingcab]

So I got a clean datsun 720 that had the z22 auto in it and I put in a l20b 5 speed. My issue is I cannot figure out why I am not getting spark. I have the hs hit4 dizzy and I'm using a coil from 200sx. 

Edited August 3, 2018 by Kingcab

[datzenmike]

Whats a "hs hit4" dizzy???? If this is an after market Chinese one....  could be anything.

 

What year coil??? Has to be '78 and up for use with a real EI matchbox distributor.

[Kingcab]

I dont know exactly what dizzy it is. But the coil is for 83. I've wired everything up with the factory harnes and and I get no spark st all. I even took the wire from the cap to the coil and no spark there 

[datzenmike]

 

 

You need a $5 test lamp.

 

 

Test for power on the coil positive side and the B terminal on the matchbox. Try crank starting it.... got power now?

 

If there is power, check that the distributor is VERY WELL GROUNDED. Don't count on the mounting bolts.

 

If you have power and ground, remove the coil negative wire and with the key on, briefly ground the coil negative side with a jumper wire and release. When you release you should get a spark. If no spark the coil is bad.

 

If there is a spark, the module isn't telling the coil to spark. Possibly bad....

 

Take the cap off and crank engine... is the rotor turning???

[Charlie69]

The wiring harness is wired for the automatic that uses an inhibitor switch and relay.  The inhibitor switch has 4 wires, 2 for the reverse light and 2 for the park/nuetral switch switch.  In order for the truck to start the the automatic had to be in park or neutral position on the automatic shifter.  The park/nuetral wires on the 1980 720 L20B automatic wiring harness is blue with red stripe and a brown.  The reverse light is yellow with red stripe and yellow with blue stripe.  I am guessing that you harness has the same color wire.

 

Kelmo had this problem with a B210 that originally had an automatic in it and he changed to a 5 speed.Send him a pm and he will share his un automatic wiring adventure with you.  not sure which B210 he had the automatic in.

 

What wires did you hook up on the five speed transmission?

 

You should use the wiring for the coil the has the larger gauge wires.  You should also use the the coil from the L20B.

[datzenmike]

All the info was clearly there and ... I missed it.  (?these suck)

 

Just join the interlock wires together, to send power to the coil and module.

 

Charlie I have a 720 coil on my 710 L20B w/matchbox. They are identical to the earlier ones. I found the old one was carbon tracked and just went out and pulled one off my old Z24 engine.

[Kingcab]

Perfect thank you so much when I get home tonight I'll chek into all this and give you my feed back. 

[Kingcab]

So I hooked up the park and neutral wires the way they should be. But I still have no spark so I just ordered a new module for my dizzy sp hopefully that will fix the problem. I'll keep you guys posted.

[Kingcab]

One other thing that has not been answered I don't think.. the stock harness has wire set up for 2 coils so what wires should hook up to the coil and dizzy?  Theres a brown n red and a blue and yellow and the stock dizzy wires are blue red and black w/white stripe. I could just be overthinking things but I'd like other advice on what I should use 

[Charlie69]

On 8/4/2018 at 8:34 AM, datzenmike said:

Charlie I have a 720 coil on my 710 L20B w/matchbox. They are identical to the earlier ones. I found the old one was carbon tracked and just went out and pulled one off my old Z24 engine.

Good to know, I thought there was a difference in ohms.

[Charlie69]

On 8/4/2018 at 7:03 AM, Charlie69 said:

You should use the wiring for the coil the has the larger gauge wires.

This would be the primary coil wiring for using with the L20B.

 

A friend of mine from Guam installed a Matchbox L20B distributor in his Z24.  He actually loves the distributor swap.  His Z24 Is running twin side draft Mikunis and is built for drag racing.  Building high perfomance z24s is a Guam thing.

Edited August 6, 2018 by Charlie69

[datzenmike]

8 hours ago, Kingcab said:

So I hooked up the park and neutral wires the way they should be. But I still have no spark so I just ordered a new module for my dizzy sp hopefully that will fix the problem. I'll keep you guys posted.

 

It can get expensive buying parts that might not need replacing.

 

Check for power with the key on and trying to start at coil and module.

Check coil for continuity or ground the - terminal with key on to cause a spark.

Check module/coil wiring

Check module and distributor ground.

 

Coil power? Just pick one and use it. Make sure the module gets power from the one you pick. Tape the other up so it cant touch anything.

 

24 minutes ago, Charlie69 said:

Good to know, I thought there was a difference in ohms.

 

All EI coils '78 and on are the same resistance. Between 0.75 and 1 ohm.

[Charlie69]

Did you contact Kelmo?  It might save you a bunch of time and money.

[Kingcab]

I messaged him but no response yet.. and I used the stock wiring for the coil and still no spark. Is the module suppose to get hot? It still wont spark but I noticed it gets hot 

[DanielC]

When I got my first matchbox distributor, I bench tested it, with a coil.   I could be wrong, but I think I remember the matchbox shutting down, drawing very little current until the shaft was turned.  In other words, the matchbox should not be getting hot.

 

Almost every ignition system works the same.  12 volts is applied to the coil.   There is a switch on the ground side of the coil.  This switch is opened when a spark plug is to fire.  

The switch on the ground side could be a set of points, mechanically connected to the engine.  It could be a "black box" controlled by a trigger in the distributor, it could be an engine computer telling a ignition module to switch the coil off.

 

It could be a 1948 gas farm tractor, or a 2019 whatever with coil on plug ignition.  Battery power is applied to a coil, a switch opens when the coil is to fire.

[datzenmike]

 Correct Daniel. The EI module only draws current if the engine is running. If turned on but not started it will sense this in a few seconds and stand down so the coil doesn't over heat nor drain the battery. It also has a current limiting circuit so no matter what impedance the coil is only a set current flow is allowed. One other thing, the dwell time increases  or decreases as the RPMs go up and down so the coil has lots of time to saturate.

[Charlie69]

Kelmo is a busy man as he owns an airport.

 

Have you turned the key on and checked for power at the coil?

 

Have you plugged the park/nuetral wires together?

 

Have you checked the fuses?

 

I hate to start you over but a $5 test light can help a lot.

 

Did this truck run before the L20B 5 speed swap?  It has to be sometihing simple or over looked.  It is and ignition sytem not Rocket Science.

 

I just went through Kelmos Coupe Build and found this;

 

So I had walked away from the wiring issue (ok, more like took a trip) I was dealing with several months back. As stated before, this thing used to be an automatic and had a starter relay that I suspected was bad. Long story short, decided to only hook up the wires going to the reverse switch and leave the other ones out of the loop.  Well, it will now start and run.

[Kingcab]

So I ordered a new module for the dizzy if that doesn't fix the spark I will literally try anything to help as this is my daily and have no other vehicle. I'm pretty sure the module isn't suppose to get hot to touch. So I feel it has gone bad. But once get a new one and rule it out I will try all of what yo guys have suggested. Thanks again for all the help guys! I'd be nowhere without my fellow ratsun brothers!! I'll keep you all posted on what happens.

[Kingcab]

Much love for the ratsun brothers! Cant find ppl like you in person! ❤❤

[datzenmike]

3 hours ago, Kingcab said:

So I ordered a new module for the dizzy if that doesn't fix the spark I will literally try anything to help as this is my daily and have no other vehicle. I'm pretty sure the module isn't suppose to get hot to touch. So I feel it has gone bad. But once get a new one and rule it out I will try all of what yo guys have suggested. Thanks again for all the help guys! I'd be nowhere without my fellow ratsun brothers!! I'll keep you all posted on what happens.

 

The best way to rule out  a problem is to diagnose it. What if the wiring is wrong or the fuse blown? Just keep buying modules, coils, ignition switches?

[Kingcab]

All fuses are good I chek them after each time I wore up the coil a defrent way. And I have it all wires correctly from what all the wire diagrams show that I have seen 

[nl320what]

I had a custom setup on my Z20, but does any of this wiring help?

 

Mine didnt run and it was the magnetic trigger collar that was cracked, new one got it going again.

 

[datzenmike]

4 hours ago, Kingcab said:

All fuses are good I chek them after each time I wore up the coil a defrent way. And I have it all wires correctly from what all the wire diagrams show that I have seen 

 

Now get a test lamp and check for power. It's invisible so all the inspecting in the world won't show it.

[Kingcab]

I've tested all the wires to make sure I'm getting power also I used a test lamp and a volt reader. 

[Kingcab]

I know for a fact that the coil is getting power and the coil is not bad. I've tested it all  and my dad has gone through and double triple checked it. And all fuses are good and getting right volts to them as well. And also the ignition switch is also good and reading good volts