2.1 DJ Doka lost it's spark - head scratcher!

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Yozza
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2.1 DJ Doka lost it's spark - head scratcher!

Post by Yozza »

Ay up,

It's been a while since I've been on here :shock: but I need some help!

I'm in the closing stages of a very long term project and I've got one more hurdle before she moves under her own steam out of the garage (for the first time in 4 years) :shock: .

It's the classic problem of - it won't start. I've recently installed a new fuel pump, and she has run with that pump, the last time I fired her up she ran (weakly) and then cut out, I thought it was fuel so I put a couple of gallons in but she won't start, I'm convincved it's not fuel as I can smell it when she turns, I took a plug out and earthed it and there is no sign of a spark.

I've cleaned up the earths around the engine and under the dash.
Checked impedance on coil and HT leads, plugs are clean and gapped.
I've got 12v at the primary and secondary (terminals 1 & 15) on the coil.
Checked dizzy cap and rotar, both are newish.
Tried an alternative HT lead from coild to dizzy.
Checked fuses.
Scratched my head a lot, but that didn't help either!

Checked all the connections around the engine as it has run but then cut out, as if a connection was at fault.

Can any of you knowledgeable folk assist before I start trawling the web? :D

Cheerz
T25 '90 2.1i 16" Doka
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Aidan
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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Aidan »

have you got spark from coil to dizzy ?

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Dutchdude
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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Dutchdude »

Hi,

I've had the same problem on my dad's van, also a 2.1 petrol. It turned out is was the hall sender inside the distributor! After I located one I changed it over and it has been running fine ever since.

Cheers
1991 Syncro Westy 16"
1990 Westy California
2003 Karmann Colorado 580H
1990 Golf mark 2

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Yozza
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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Yozza »

Cheers Ade, I'll check but I suspect not, as there was no spark at plug and rotar and dizzy cap are new. If there is no spark could the coil be knackered even though it has the right impedance across primary and secondary?
Cheers
T25 '90 2.1i 16" Doka
JCB 3C MkII
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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Aidan »

more likely to be the TCi unit on a DJ, they seem to go weak intermittent fail when hot then fail finally

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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by max and caddy »

Hall sender is also very prone to failing when hot then coming back to life when cooled down...tci is easier and cheaper to swap out to test however..hall sender is inside the izzy by the way but has nowt to do with the rotor or cap...

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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Yozza »

You'll have to help me bust the acronym first...is TCi Transistor Controlled Ignition? And where can the little critter(s) be found and tested?

Thanks,
T25 '90 2.1i 16" Doka
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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by silverbullet »

Little black thing like a flattened matchbox with a 5/6 wire multiplug, LHS of engine bay next to coil, near the corner.

BTW I have had a couple of "oh bugger" mornings recently where the SS chugged on 2 cyls for a minute or two first thing, wouldn't idle without assistance on the pedal then cleared and has been fine ever since.

I think that the plug leads have got damp in them (or the insulation is breaking down), the last set had green terminals when I pulled the boots off...

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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Yozza »

Thanks for the replies fellas.

I was hoping to reply with the root cause, but I'm still scratching my skull.
I've got a good spark from coil to dizzy.
Checked hall sensor and that switches between 0v and 10.8v, checked that the signal is getting to the TCI unit (it is).
No spark out of the lead to the spark plugs (with or without plug).
Changed rotar and dizzy cap, HT leads.

Still no spark out of the plugs :?

I noticed an earthing tab on the case of the dizzy, should this be earthed?

I'm thinking all of my HT leads must have suddenly failed???

Is the gearbox earth strap the earth for the engine main block too as the braid and earths in the engine bay are secured to the LHS cylinder head. If it is, then this too could be the culprit?
T25 '90 2.1i 16" Doka
JCB 3C MkII
Thwaites 6000

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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Aidan »

does timing mark on disi line up with rotor arm ?
wondering if disi drive is slipping/failed
spade on disi not used unless you have metal shroud around cap long gone usually

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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by axeman »

Remove the king lead and put a spaire plug in the end of it, and earth it on the engine, now with some scrap wire attach a spade and connect it to the negative side of the coil earth this wire on the engine block repetidly and quickly you should have a spark every time you earth this wire.
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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Dutchdude »

Clean the earth connections under the M6 bolt on the left cylinder head. The M6 bolt might snap off, but there is another M6 threat right next to it. Usually lots of corrosion here, so bad ground connection. One of these wires is hooked up to your distributor.
1991 Syncro Westy 16"
1990 Westy California
2003 Karmann Colorado 580H
1990 Golf mark 2

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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by HarryMann »

Yes Rob, You can't beat a good earth when the lightning strikes...
2.1 engine and firewall earths are a nightmare..
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Dutchdude
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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Dutchdude »

Earth connection - ground connection or whatever it's called.. Hey it's foreign lingo for me, I'm Dutch you know.. :)
1991 Syncro Westy 16"
1990 Westy California
2003 Karmann Colorado 580H
1990 Golf mark 2

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Re: 2.1 DJ Doka lost it's spark - head scratcher!

Post by Yozza »

Thanks fellas,

I've had a session in the garage and checked all of the above.
Dizzy and rotar line up with the mark at TDC.
Wired up a plug to earth and connected a lead from coil to earth and it did spark.
Cylinder earthing point is clean along with all of its ring terminals.

I'm gonna have a closer look at the HT leads, but unless all four have failed I should still get the occasional 'pup pup'as she fires. Can HT lead impedance measure ok (when off the vehicle) but still fail when in use?
T25 '90 2.1i 16" Doka
JCB 3C MkII
Thwaites 6000

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