:)I've had a brief read through the posts on this thread, but please accept my apologies if what I'm about to say has already been covered......

When you originally checked for a spark and found none, did you test it at one of the HT leads where it connects to the spark plug, or did you check at the main coil HT lead?

If you checked it at the former, may I suggest you check it at the later too! It's not unknown on the pushrod Skoda engine for the distributor drive to go wrong. What I'm basically coming to is this....make sure the distributor is turning when the engine is being cranked!

Further to daverapids suggestion, I have just thought...

Also check the carbon brush in the centre of the dissy cap is there and free to spring back and likely to contact the rotor arm (I think these tend to break too).

No spark at king-lead.

Not had an opportunity to test/check anything else again yet, too cold & my body's complaining :(

No spark at king-lead.

Not had an opportunity to test/check anything else again yet, too cold & my body's complaining :(

at least you've narrowed it down to no spark...

things that control that are..

Immobilser

ECU

Crank sensor?

You wouldn't chuckle much!

I've just done basic testing on the coil - powered up with ign on, ECU disconnected, earth the green wire and...

Nothing!

Tried the 2nd hand replacement coil in the same way and...

SPARK! A weedy yellow spark which wouldn't be enough to run the engine.

So! New coil needed because I need a big fat blue spark. £79.99 +p&p from J M Butt :eek: Local prices to be found out tomorrow.

:woot:

at least you've narrowed it down to no spark...

things that control that are..

Immobilser

ECU

Crank sensor?

It was always no spark...

It was always no spark...

:rofl:like I read 5 pages:thumbup:

just thinking out loud- what have you checked that I've listed?

Replaced:

Coil (2nd hand), hall sender (twice - 2nd hand & new), ECU, disabled immobiliser, reconnected ects (broken wire), bypassed one ign wire in case that was broken...

Two duff coils... The coil faults DON'T show up on VAG com.

Replaced:

Coil (2nd hand), hall sender (twice - 2nd hand & new), ECU, disabled immobiliser, reconnected ects (broken wire), bypassed one ign wire in case that was broken...

Two duff coils... The coil faults DON'T show up on VAG com.

Sounds like you're well on top of it...

hall sender takes signal from crank doesnt it?.

something seems to be stopping the coil from getting signal to spark, or enough juice..

what are the battery to coil wires like?

Yes, Hall Sender = crank sensor (5v fed rare earth magnet sensor, sends a square wave pulse back to the ECU at twice per engine revolution, determines engine timing).

Main power feed to coil is ign. fed - black wire only one fuse - No. 20. Looks like full current from my eye-sensor on the test lamp

I'll double check the original coil in the morning.

This has been a 4+ week epic

Yes, Hall Sender = crank sensor (5v fed rare earth magnet sensor, sends a square wave pulse back to the ECU at twice per engine revolution, determines engine timing).

Main power feed to coil is ign. fed - black wire only one fuse - No. 20. Looks like full current from my eye-sensor on the test lamp

I'll double check the original coil in the morning.

This has been a 4+ week epic

fun fun fun!

what about earthing? does lump spin freely? and earthing for coil,if any...

Looks like hopefully this is going to be sorted soon I'd imagine the coil is a dumb terminal and the ECU wouldn't register any lack of spark.

Looks like hopefully this is going to be sorted soon I'd imagine the coil is a dumb terminal and the ECU wouldn't register any lack of spark.

Precisely.

Not really expecting being able to contribute, but I did some random googling. My god, some strange "manuals" to be found ot there.:eek:

Can't resist the temptation to pass on this goodie:

"Starter works but engine does not start" (sounds familiar, right?)

"Step 1: Is ignition system in proper condition? Check battery voltage, ignition distributor, spark plugs, ignition coil, ignition timing, etc.

Yes: Go to Step 2

No:...

*

*

*

*

*

*

*Repair or replace damaged ignition components"

See, there's a simple solution after all:rofl::rofl:

A little bit more interesting was this one:

"Keep in mind that the Bosch ECU must see a certain minimum voltage to wake up and send the spark/fuel signals. Even though the battery might seem like it is cranking the engine over OK, if it is marginal there may not be enough voltage to both crank the engine and meet the ECU's threshold. Especially if you've been cranking it a while trying to get it started (thus wearing down the battery).

Charge up the battery or push start it or jump start it."

You've told us that your battery has been flattened, of course you've recharged it, but could it be that you cut it off a bit early so that a few (but important) tenths of volts are missing?

Well, you probably haven't overlooked this one either.

Not really expecting being able to contribute, but I did some random googling. My god, some strange "manuals" to be found ot there.:eek:

Can't resist the temptation to pass on this goodie:

"Starter works but engine does not start" (sounds familiar, right?)

"Step 1: Is ignition system in proper condition? Check battery voltage, ignition distributor, spark plugs, ignition coil, ignition timing, etc.

Yes: Go to Step 2

No:...

*

*

*

*

*

*

*Repair or replace damaged ignition components".

:rofl:

See, there's a simple solution after all:rofl::rofl:

A little bit more interesting was this one:

"Keep in mind that the Bosch ECU must see a certain minimum voltage to wake up and send the spark/fuel signals. Even though the battery might seem like it is cranking the engine over OK, if it is marginal there may not be enough voltage to both crank the engine and meet the ECU's threshold. Especially if you've been cranking it a while trying to get it started (thus wearing down the battery).

Charge up the battery or push start it or jump start it."

You've told us that your battery has been flattened, of course you've recharged it, but could it be that you cut it off a bit early so that a few (but important) tenths of volts are missing?

Well, you probably haven't overlooked this one either.

Good thinking I'll get the battery back on charge tonight. (I'd have to anyway.)

One point I have found whilst googling how the ign coil works is that without the capacitor (as in a points engine) the spark will be weak and yellow rather than the big fat blue one I was expecting (The ECU must incorporate the capacitor too - oh, I wonder...). Anyway, no spark whatsoever from my old coil, not even a weedy yellow one so that's being binned. I'll have a dig through my oddments jars to see if I have an old ign. capacitor & test the coil(s) with that included in the circuit. (Addition) I have TWO old capacitors to test with :lol:

As Woody says: Fun fun fun!

I've had the top off my spare ECU and it has two car ignition sized capacitors in it, so that answers that one. The green ign. wire IS the equivalent of the coil to points wire. I guess the second capacitor in there is for redundancy in case of failure. I bet they're the most common failure in ECU's of this type, yet the charge is £200+!!! for repairing them A "normal" ignition capacitor is a couple of quid and they do fail fairly regularly (5 years or so maybe).

As a side note, the main CPU in there is a Seimens one, same as one of the MPi systems.

As a side note, the main CPU in there is a Seimens one, same as one of the MPi systems.

That's interesting, I always thought the SPI system was Bosch. Have a spare 135 ECU that's no use to me, never thought to pull it to pieces. Hmmm.

The "star" head screws can be cracked with a pair of pliers and then removed using a small screwdriver

The "star" head screws can be cracked with a pair of pliers and then removed using a small screwdriver

also, any mobile phone repair kit worth its salt will have a screwdriver with the right adapter:thumbup:

so have you replaced the capacitor

so have you replaced the capacitor

I HAVE SPARK!!! A nice big fat juicy blue spark So I won't be needing to replace any capacitors.

It still don't run though :confused: It has petrol too, a nice fine mist on the plugs.

Ummmmmmmmmm..........

:woohoo::woohoo::woohoo:

Victory!

No need for these then:

PS - did you identify the fault or is it a Christmas miracle?

It's not even pretending to fire either. Nary a pop, a bang or a fart.

I'll have a search of other threads again now.

It's not even pretending to fire either. Nary a pop, a bang or a fart.

I'll have a search of other threads again now.

could be a compression issue now then?

if you have spark and fuel, and no obvious blockages in air intake...

maybe I should disconnect the engine temp sensor again :lol:

I'm going to give it a spin with the ecu disconnected & the plugs out (get some fresh air through it).

(Then try disconnecting the ects )

maybe I should disconnect the engine temp sensor again :lol:

I'm going to give it a spin with the ecu disconnected & the plugs out (get some fresh air through it).

(Then try disconnecting the ects )

Fingers crossed mate! suddenly woody's H/G change doesnt seem quite as bad...