Page 1 of 3

T25 Starting fault

Posted: 03 May 2011, 19:04
by PorkchopII
Hi Everyone, Hope you can help with my problem!

I have got a 1984 1.9l petrol T25, It has been fine ever since I have had it but for some reason it will not start now. I have replaced the starter motor, Ignition coil, Ht leads, distributor cap, rotor arm and spark plugs but it still does not start.

It turns over fine but does not fire once, You can smell petrol so I know it is not being starved of fuel but it just will not fire once.

Does anyone have any ideas??

Re: T25 Starting fault

Posted: 03 May 2011, 19:41
by kevtherev
checked for sparks?
How did you check for fuel delivery?
by taking the pipe off and seeing it squirt?

has the timing been moved?

if you have fuel , sparks and good timing it should go

Re: T25 Starting fault

Posted: 03 May 2011, 23:25
by Eta-Beta
where abouts are you mate?

Re: T25 Starting fault

Posted: 04 May 2011, 07:29
by PorkchopII
As far as I know I don't think I'm getting a spark as I earthed a plug on the engine and got nothing, That's why I have changed all the part's I listed in previous post but still no joy.

The vehicle hasn't moved since I parked it there at the start of March and the timing has not been moved. I know there is fuel in the engine as it stinks of un-burnt fuel from the exhaust when turning it over, And like I said before it is turning over fine.

I'm getting full voltage at the junction box but it seems to be 0.4v down at the ignition coil, Which I wouldn't think would make a difference?!?

I'm in Bournemouth.

Re: T25 Starting fault

Posted: 04 May 2011, 09:39
by Ian Hulley
So you've power at the coil but no spark ? .... HT 'king' lead (the one from the coil) ? Ignition amplifier ? Engine loom earth on top of left cylinder head ? Multiplug out of distributor ?

Ian

Re: T25 Starting fault

Posted: 04 May 2011, 10:26
by kevtherev
Perhaps a member in bournmouth can lend you a hall sender unit to see if that has failed.
This also would stop sparks to the plugs
they are not cheap so test it first

Re: T25 Starting fault

Posted: 04 May 2011, 11:06
by PorkchopII
Yeah full power at the coil but no spark as I can see.

I have changed the HT king lead along with the other 4, Where is the ignition amplifier and hall sender unit??

What does the solenoid inside the junction box at the rear do?

Many thanks for all your help!

Re: T25 Starting fault

Posted: 04 May 2011, 11:44
by Ian Hulley
PorkchopII wrote: Where is the ignition amplifier

This is a small black box with a heat sink on the back screwed to the side wall of the engine bay between the coil and the black box of confusion. Late ones look like this ... Image

Ian.

Re: T25 Starting fault

Posted: 04 May 2011, 12:37
by PorkchopII
That is the amplifier that is fitted to mine, Would it be worth changing it?? Or is there any way to can test it??

Re: T25 Starting fault

Posted: 04 May 2011, 13:28
by Ian Hulley
PorkchopII wrote:That is the amplifier that is fitted to mine, Would it be worth changing it?? Or is there any way to can test it??

The best thing to do is to swap it with a known good one, that way you can prove/dissprove it's that .... is there no-one local to you who has a petrol ? They are the same fitted on Golf/Jetta/Scirocco/Polo carb models of the same age.


* what about this guy ? https://club8090.co.uk/forum/memberlist. ... le&u=10531
Ian.

Re: T25 Starting fault

Posted: 04 May 2011, 15:01
by Mocki
the relay in the blackbox is for the carb heater, controlled by the sender switch in the thermostat housing and not anything to do with your not starting fault.

check the brown earthlead onto the top of the lhs head, its the earth for the ignition system.

also check the loom from the ig amp to the dissy

Re: T25 Starting fault

Posted: 04 May 2011, 16:05
by jswagger
PorkchopII wrote:Hi Everyone, Hope you can help with my problem!

I have got a 1984 1.9l petrol T25, It has been fine ever since I have had it but for some reason it will not start now. I have replaced the starter motor, Ignition coil, Ht leads, distributor cap, rotor arm and spark plugs but it still does not start.

It turns over fine but does not fire once, You can smell petrol so I know it is not being starved of fuel but it just will not fire once.

Does anyone have any ideas??


Is it a DG engine?

I had a smilar problem and I changed the dizzy cap, leads & coil and it turned out it was the ignition amplifier that was at fault.

Re: T25 Starting fault

Posted: 04 May 2011, 19:43
by PorkchopII
Yeah mine is a DG engine, To be honest it sounds like it is the ignition amplifier from what you are all saying! I'm guessing they are easily avaliable?!?

Will check the loom from the amp to the dizzy and the earth lead hopefully before the weekend as I really want to get out on the old beast! :cry:

Re: T25 Starting fault

Posted: 04 May 2011, 20:44
by jamesc76
You say you changed all the leads, are you 100% sure there on the right way?

Re: T25 Starting fault

Posted: 04 May 2011, 21:12
by Ian Hulley
PorkchopII wrote: I'm guessing they are easily avaliable?!?

Yep :ok http://www.brickwerks.co.uk/shop?page=s ... ory_id=122 Best to check it by swapping first though :wink:

Ian