Ignition problems with 4AGE Bigport

[speed_humper]

Car model: AE86 (Kouki Hatch JDM)

Engine type: 4AGE Bigport (7 rib)

Problem: Ignition (No spark)

Bit of a weird one, seems somewhat intermittent too, heres a rundown of what happened and what I have tried. Keep in mind that the problem usually rears its head when I try to start it after cold days/nights

- Engine will turn over, starter motor works fine, can smell fuel in engine bay so injectors work too.
- First thing I tried was replacing coil, seemed to work initially, as when I replaced it it started up again and drove fine for about 4 days.
- Died again 4 days later, tried replacing coil again, no luck this time.
- Tested master ignition lead (one that goes from coil to distributor), gives good spark.
- Checked all the ground points around the engine, couldn't find any thing out of the ordinary (no corrosion, all ground wires connected)
- Figured problem was with Ignition module, took it apart to see if anything was burnt, couldn't find any signs of that.
- Tried one last thing, cleaning up/sanding the two little terminals from the ignition module that bolt onto the coil.
- SUCCESS, it started up, ran fine even on some really cold days, with no issues whatsoever, for a good 2 months.
- Went for a long drive to lakeside and back yesterday, was perfect. Tried to start her up again this morning, no dice.

Seriously have no idea what the issue is here, I have an inkling that it might be some odd grounding issue to do with the coil and how it is mounted on the car?? Im using the stock coil mount bracket.

Could also be my battery? Its old, and while it has the juice to turn my starter motor, I wonder if it is providing enough current to allow a spark. Ill see if I can find a replacement battery to test.

Any help is greatly appreciated.

[Matt]

Check the wiring on the dizzy plug, they flog out and can cause the issue you are experiencing. A diagnostic check when it won't start will also shed more light on your problem.

[speed_humper]

Thanks Matt, ill look into those. Cheers

[timbo]

Sounds like heat could be a problem, as is metal expands when hot. Could be a connection that isn't making good contact. As above, check dizzy plug, clean with some contact cleaner and do the same with all plugs, also make sure that are actually connecting properly.

[speed_humper]

Thanks for the help guys, got the car running.

As for how it started working again, still a bit of a mystery, all I did was shake the CAS wiring a bit and it started up again. I also took the distributor cover off and gave all the contacts a good clean with contact cleaner and degreaser.

I forgot to mention that the distributor oil seals are damaged and there is oil leaking from behind that, possibly affecting the wiring coming out of the CAS. Either way the problem seems to be isolated around the CAS and the wiring.

Thanks again for the help.

[Matt]

id look into replacing those seals before you get stuck on the side of road due to the oil getting in there