Electronic Ignition

[corollaart]

How would i bench test a 5K internal igniter dissy.

 

I did run it many years ago but the car just stopped from memory ,didnt bother with it just put the points

 

dissy back in.

 

Can you still buy the igniters??

 

Banjo! kicken 5k! Keith!

 

thanks in advance rob

[Taz_Rx]

Don't know if you can buy those igniters specifically anymore but you could bypass the internal and just use another igniter off a different car. They're little more than a relay really.

[ke70dave]

The GM ignitors are the go as there is heaps of information around about them and cheap from the wreckers.

 

I used a GM ignitor with my suzuki sierra coil and electronic distributor (ie VR sensor). I can't imagine its much, if at all different to a corolla setup.

[GJM85]

I have one with the internal igniter that I didn't use because it didn't work.

One day I just pulled it down to see what was inside. I cleaned it and lubricated it. Then reassembled it and reset the gap between the pick up and the shaft at 0.5mm. All of a sudden it was all good. Don't know what I did but it works, although I don't use it.

Edited October 14, 2014 by GJM85

[altezzaclub]

If it were me, I'd put it in a vice, hook up 12V and a coil with one spark plug and spin the drive by hand. ..or with an electric drill!

 

Check the wiring and the air gap, maybe its still fine like gav's.

 

I've just spent two weekends getting a VK running with young Rob. At the end of the first one we found the new electronic dizzy rotor wasn't touching the old but similar-looking cap, but the spark would jump the gap occasionally and fire a cylinder. We had the timing light on all sorts of places, carb checked, poured fuel in, tried all sorts of shit.

 

After it just ran, the following weekend we couldn't get it going, and it took all that weekend to find out that the brand new spark plugs he had put in his rebuilt motor were shorting down the ceramic insulator instead of jumping the gap! They'd got pretty fouled from the previous weekend.. New plugs and it runs like new!

 

So, we checked and checked everything, but its amazing how hard it is to see a simple problem right in front of you!

[7000rpm]

I would check continuity of the coil using a multimetre

[corollaart]

Thanks Guys ,I tried the wire up as Keith suggested but all that happened was the coil got very hot and not a sign of spark from the dissy .

 

So Dave, Taz would i remove the igniter all together ?I'm not really good with all these electric bits !!!

 

Then run a external igniter and coil with module ,as in the FAQ section??

 

You may have to dumb it down for me.

 

Parts i have laying around is one dead 5k dissy one coil with a external igniter from i think st141,coil from ae71,coil from ke55s,coil from ae82.

 

Dave the igniter from GM is from a VR taxi ?it would be good to have a simple set up where parts are easy to get over the counter.

 

Thanks Rob

[ke70dave]

ahh good fun. I shall attempt an explanation!

 

note, in heinsight i was wrong about using a GM (ie general motors). you will see why below....

 

So i dunno how much you know of how an electronic distributer ignition system works, but the basic theory is as follows.

 

You have 3 main components, the VR sensor in the dizzy (Variable reluctance sensor, essentially metal passes the sensor which induces a current), the electronic module (essentially a high powered transistor), and the Coil.

 

note, Dwell = Time required to charge the coil to get a spark. (typically in the 2-3ms range)

 

So you have 2 types of electronic modules, you have "dumb" ones, which do not have Dwell built in, and you have "smart" ones which have dwell built in.

 

The "dumb" modules are "generally" used with an EFI computer (not always), but basically with different types of coils and depending on how much spark you want etc, you can adjust the dwell time to suit. This is out of the scope of what you are looking at, and the GM modules are dumb modules (i got confused). In a haltech or aftermarket ecu you can program the dwell to suit different coils.

 

I can only assume that the 5k electronic module is a "smart" module, in that it sorts out the dwell (charge) time for the coil without any additional input.

 

Remember how a coil works, coil is charged for the dwell time, and then it is callapsed, which induces a current in the secondary coil which makes the spark (something like that!)

 

So back to how it works in a 5k (or any basic electronic ignition carby car)

 

There is a 4 prong widget inside the dizzy at camshaft speed, it goes past the VR sensor, this sends a signal to the electronic module, the electronic module charges the coil for the dwell time (~2ms), then it calapses the coil, which sends the "spark" down to the distributor, and the spark is then distributed out to the correct cylinder. Rinse and repeat for each spark event.

 

So if we assume that your electronic module in your distributer is the culprit (its unlikely that the VR sensor is stuffed, from all accounts they are bullet proof). What you need to do is connect the VR sensor to another "smart" electronic module (remember dwell time built in).

 

That ST141 might do the job for you, i don't know much about the ST141, is the st141 EFI? or carby with electronic ignition? If the electronic module is 'stand alone' and not connected to the ECU in anyway, then you can almost guarantee its a "smart" ignitor, and thus will work for you.How many wires on the st141 ignitor?

[altezzaclub]

I tried the wire up as Keith suggested but all that happened was the coil got very hot and not a sign of spark from the dissy .

To me that suggests the electronic unit is just shorting the coil to earth, so it is definately borked!

 

Any other ideas?

 

The ST141 module looks like an external unit from this ad-

http://www.myshopping.com.au/ZM--1228031329_Toyota_Ignition_Module_Avante_ST141_11_85_4_87_2S_C_2_0L

[corollaart]

Dave I'm not sure if it was EFI or Carby.

 

So it has two plugs coming from the ignitor.

 

The 1st one is two pin red wire and white.

 

The second one is huge 5 pin with 4 going directly to the igniter and the other to the positive on the coil

 

then back to the igniter.

 

rob

 

Keith its the 240 dollar one !!!!!bloody hell ha ha

Edited October 15, 2014 by corollaart

[ke70dave]

Sounds too complicated. You are probabky better off getting one from a 4ac dizzy or something

Edited October 15, 2014 by ke70dave

[corollaart]

So i went thru my modest parts and found 3, 4ac dissys 1 points 2 electric .

 

They look very basic in side ,magnetic pickup 2 wires to the module then 2 wires from module out.

 

So looking at the 5k dissy there seems 2 parts two it .

 

The magnetic pick up then 2 wires to the ignitor then 2 wires out of the housing to coil.(simple really)

 

How am i going so far Dave?

 

My thinking which is take the two wires off the original ignitor (even remove it altogether)

 

Keep the magnetic pick up ,and hook up the two wires from that two the ae module.???

 

Shoot away :doh:

[altezzaclub]

photos needed!

[ke70dave]

Sounds like you are onto a winner there.

 

Do the wire colours match on the 4ac vs 5k one? As there is a polarity to the VR sensor.

Edited October 16, 2014 by ke70dave

[corollaart]

5K Distributor Igniter (picture below)

 

4AC Ignition Module, pink and green wire goes to distributor, two black wires go to VR sensor, although one of the black wires has a smaller terminal than the other (would the smaller terminal be negative?) (picture below)

 

The 5K Distributor, the two wires from the VR sensor to the ignitor? (picture below)

 

4AC Module, 4 Terminals with numbers 3, 7, 15, 16.

Terminal 3 is the black wire with the small terminal, 7 is the larger black wire these go to the VR sensor, whilst 15 and 16 (pink, green) go to the coil.

Bosch 3820. (picture below)

 

So I'm not sure which way the wires from the 5K sensor hook up to the 4AC ignitor, I'm guessing the smaller black terminal is negative.