Engine cut out - coil?

[Ross]

THis ignition prob is driving me crazy!!!

Now, the engine will sometimes momentarily cut out completely (when this happens, the tach drops), and also sometimes drastically loose power (no drop in tach, still boosting etc.). These two symptoms usually happen at roughly the same time, so i suspect they are different symptoms of the same prob.

Plugs, leads, disty cap etc are all fine. ECS light does not come up.

Could this be caused by a dying ignition coil?

[stngllhm]

to me it sounds like it could be a loose connection between the distbuter and coil.

[Ross]

Yeah, i think i may have just found it. (after replacing the coil - oh well the one that was in it measured 3.6 ohms across the primary anyway!).

One odd thing i noticed - there is a relay on the power source for the coil - the original power wire is only used to signal the relay, was this standard on some models (my wiring diagram doesn't show it) or has someone added it for some reason?

 

Thanks!

[Ross]

These made no difference, ignition still cutting out. I have tried runnign the coil straight off the battery, still no diff. Wires between coil & distributor seem fine. Apart from the module, is there anything else?? HAs anyone ever experienced a module failing this way?

The engine willl always run to some extent, which from what i have heard, is odd for a dead module.

 

ANother odd thing, there is a large whiteish wire coming off the negative side of the coil, that does not appear on my wiring diagram. The engine will not run without it. Does anyone know what this is?

 

cheers.

[exister99]

I had a similar problem and it turned out to be the pickup coil, AKA ignitor, AKA ignition module. It looks like a misshapen donut wrapped around the distributor shaft where it emerges from the distributor body.

 

This thing is basically an integrated circuit and with age it develops micro cracks. The right temp and a little jiggling opens up the crack and voila! dead engine. Happened to me along the Lochsa River, beautiful place to break down.

 

The new unit runs about $165, but a new distributor with a new unit inside costs about the same. I bought a used distributor for $10 and took the ignition module out of it. The thing worked like a charm and saved me over $150. Plus I can rebuild the used distributor for a spare.

 

Good Luck!

[naru]

These made no difference, ignition still cutting out. I have tried runnign the coil straight off the battery, still no diff. Wires between coil & distributor seem fine. Apart from the module, is there anything else?? HAs anyone ever experienced a module failing this way?

The engine willl always run to some extent, which from what i have heard, is odd for a dead module.

 

ANother odd thing, there is a large whiteish wire coming off the negative side of the coil, that does not appear on my wiring diagram. The engine will not run without it. Does anyone know what this is?

 

cheers.

 

The relay in the coil+ circuit is non-stock.

Not sure about the "large whiteish wire".Coil - should have 2 wires,one sraight to the module,the other is the ignition pulse signal to the ECU and tach.On my 84 turbo they are both yellow.

 

Considering that you`ve swapped coils and powered it directly from the battery,the module IS starting to look suspect.As I mentioned previously,they usually fail completely,but,I`ve seen them fail only when warmed up and only in extra cold weather too.Last failed one I disassembled had a tiny surface mount component that became unsoldered.

 

Before splashing out for a module,you may want to consider some other items.

An obscure failure that I saw once was a poor ground between a body mounted coil and the engine.In this case idle rpm would increase while leaning over the engine compartment and touching the engine!

 

An intermittent open in the wiring harness(es).

Put your ohmmeter on either end and wiggle them around.

 

Some strange failure in the knock control unit(highly unlikely).

[Ross]

Thanks guys, i replaced the module with a second hand one out of an ea82t, and has fixed the problem!!

 

I'm still baffled about the white wire on the coil, the two factory yellow ones are there too, but engine wont start without the white one??? spose it doesn't matter too much, it goes goo now!

 

One thing that worries me: THe module i bought has different numbers on it (the white painted ones): the original one said something like 15x5, the ea82t one says something like 20x5 (not sure if the numbers are right, the cars' not here at the moment). Do these mean anything?

 

Thanks.

[exister99]

Thanks guys, i replaced the module with a second hand one out of an ea82t, and has fixed the problem!!

 

I'm still baffled about the white wire on the coil, the two factory yellow ones are there too, but engine wont start without the white one??? spose it doesn't matter too much, it goes goo now!

 

One thing that worries me: THe module i bought has different numbers on it (the white painted ones): the original one said something like 15x5, the ea82t one says something like 20x5 (not sure if the numbers are right, the cars' not here at the moment). Do these mean anything?

 

Thanks.

 

Nice!

 

I replaced the module in my EA81 with a module from an EA82. The distributors are radically different but the modules are outwardly identical, except for the numbers. I have been running that module for nearly 2 years. Drove it through more blizzards than I can remember and from Idaho to Texas without the slightest hiccup from the distributor. Interpret this as you wish.

 

BTW, if any of you have any of these modules you can spare you might put them up for sale. Considering the price of the new ones you could esily get $20-$30 for a working used one.

 

Cheers!

[naru]

One thing that worries me: THe module i bought has different numbers on it (the white painted ones): the original one said something like 15x5, the ea82t one says something like 20x5 (not sure if the numbers are right, the cars' not here at the moment). Do these mean anything?

 

Thanks.

 

Every module I`ve ever seen has different #s.EA-81T and EA-82T modules are identical.

[Ross]

Brilliant news! Thanks a lot! Pity the knock sensor seems to be a different story!