Puzzle (of the automotive and electronic type)

If it's the old grounded collector kind with a high voltage PNP Ge-transistor in there it could be that the capacitor in the module has come loose. It's usually the same kind that used to sit across the points before they went to transistor ignition. If that's the case you could try hanging such a cap from coil minus to ground, in parallel.

Also, check the points. See whether there is dirt or gunk in there. AFAIR with old transistor ignitions the voltage flies up with the coil minus voltage.

It could be done sans uC although that doesn't have the right coolness factor these days. And don't forget that big blue flashing LED :-)

The FJ40 is a nice 4WD. A friend has modified his and put a Chevy engine in it, he now calls it a "Chevy-ota".

Whitney used to sell after market electronic ignition kits. Not the Bumble-Bee stuff. These had a Hall-effect sensor that went into the distributor and an external unit that drove the coil. I haven't seen a Whitney catalog for years: they are still in business:

Bad ground? Distributor to block, block to battery.

Cheers

...you did not READ what he said..there are NO points - mis-translate to magnetic pickup at worst..

(...)

Plus ignition module to distributor and all those nifty connectors.

--Winston

ch

at

Are the plugs gapped right? You might just want to clamp a neon lamp across the coil, to simulate the timing light.

ly

ith

No junkyard parts available? That would be my first choice.

That's a pretty old vehicle, but have you tried the local junkyard?

Considering where Toyota got the original six cylinder engine from...

Are the plugs gapped right? You might just want to clamp a neon lamp across the coil, to simulate the timing light.

No junkyard parts available? That would be my first choice.

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Bosch made a range of "universal" ignition modules. I'm sure hunting around you would find one for much less than $350. They were black about 75mm x

They looked like these:

ch

at

Sounds like an intermittent connection, doesn't it?

ly

I fixed a friend's Isuzu a ways back. The dealer wanted to sell him a new ignition "computer" for more than a poor dental student could afford. I traced it out and tested it--it wasn't much more than a big darlington, firing off an inductive pickup.

The Darlington was fine, the problem was the pickup gap. Tweaked that, and t'was better than new.

Good luck!

-- Cheers, James Arthur

The basics of a very good method, which uses a standard ignition coil...

The control system is around somewhere... on paper... pre-CAD ;-) It measured the current in the emitter and the base and calculated IC (HV transistor beta was ~4 at 5A :-)

This was circa 1972. Modern circuits elements will make it easier now than then.

Shown previously while arguing with El Dorko... the 5mH, 5 AMP, yes AMPERES, inductor for my CDI ignition...

Thought of that. But pulling the coil lead off, wiggling it around and plugging it back in (same physical manipulation as connecting the timing light) has no curative effect. I've been through the rest of the circuit with continuity tester, wiggling connections. And tugging on them with the engine running. No effect. Unless its inside the potted module, of course. But then, explain the timing light.

Thanks. I'll add this to my collection of notes as I ponder a DIY solution.

When I get my module built and running, I'll try to un-pot the OEM module and see if I can find the fault. The puzzle is more interesting that fixing this.

No points. It uses a reluctance pickup. That's probably why its been running for 33 years without maintenance.

The cap idea is good. If the one inside the module is going bad, this should be an easy test. But keep in mind that this fault is intermittent. I can drive for a few days and it runs perfectly.

Yes, sort of. FJ40 parts (non wear) are difficult to come by. But there's a chance that there's a cross reference* Nipondenso part for some other model.

I've pulled all the ignition parts, cleaned and re-tightened the connections in the process of replacing most of them. battery cables are (relatively) new. But there may be a block ground I've overlooked. Distributor would be a non-issue, as this doesn't use points (the mag pickup is floating and shielded).

Yes, but those caps are large and potting isn't perfect. You could have fatigue cracking in the solder joints.

I've had that in my Citroen (classic ignition with points). Drove on an autobahn ... pop ... POOF ... **BAM* ... pop ... what the hell ...? Stopped, took spark plugs out, were ok, took big fan off the crankshaft, looked at the points and the cap, looked ok. Dang. Figured I'd limp home, somehow. Put it all back in, one (!) throw with the crank ... VROOOM ... huh? Drove home without it missing a single cycle. On Sunday I wanted to get back to my university town. Crank, crank, crank ... ... crank .. *KABLAM* .. phutah ... pop. Didn't start, no matter what I did. Took the cap out. Turns out one crimp connection in the cap leads was loose and you could twirl the cap around in it. Soldered it, no problem with the ignition ever again.

I'm considering aftermarket. I'd like to not have to throw out or mod the distributor pickup (it seems to work OK).

Meh. This is the kind of inductor us power guys like playing with:

Of course, I've never actually wound one myself. ;-)