# Merlin no magic



## tomtank (Aug 2, 2011)

Hi all,


I have my camper in the workshop at the moment with a misfire fault.

All of the obvious have either been checked or replaced:

1. Leads
2. Plugs
3. Cap
4. Rotor arm.
5. Coil
6. Ignition module

But the thing still only runs on two cylinders even though i have a good spark to all plugs, i have noticed when i disconnect the servo vacuum hose the vehicle cuts out and when reconnected the engine misfire has moved from 1 & 4 to 2 & 3!!!

Has anybody come across this problem before?

BTW this is a 1989 Talbot Express 2.0l petrol.


Regards


Tommo


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## raynipper (Aug 4, 2008)

Dunno if it will be anything to do with your problem but when I have any misfire I open bonet with engine running and when it's dark. And mist water with a leaf/plant sprayer over the electrics and any HT leaks will be apparent.

If there is no arcing then look elsewhere.


Ray.


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## Mike48 (May 1, 2005)

You haven't got the plug leads attached to the incorrect cylinders have you?


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## tomtank (Aug 2, 2011)

Hi Gelathe,


I have all the leads on as per firing order 1-3-4-2, I have identified number one lead as the closest lead from the dizzy cap to number 3 cylinder.





Regards


Tommo


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## erneboy (Feb 8, 2007)

Are you using the correct direction of rotation when checking firing order and have you had the engine at TDC on number one with the rocker cover off to ensure it's TDC with number one just fired, both valves closed. It does sound very much as though you have two leads wrong. It's very easy to get confused and end up with 1243 instead of 1342 and vice versa. No harm in trying both briefly.

Failing that I would have to have another think, Alan.


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## BillCreer (Jan 23, 2010)

tomtank said:


> Hi all,
> But the thing still only runs on two cylinders even though i have a good spark to all plugs, i have noticed when i disconnect the servo vacuum hose the vehicle cuts out and when reconnected the engine misfire has moved from 1 & 4 to 2 & 3!!!


Hi,
When you say servo vacuum pipe is it the one for advance and retard on the distributor or the one for the brakes?


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## inkey-2008 (May 24, 2008)

Have you check the play on the rotor shaft. I had car that missed fired and as you have done check and changed the obvious but it was wear on the shaft giving varying points widths. 
Another thing check the weights springs and the wire to the points inside the rotor body. 

Andy


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## cabby (May 14, 2005)

can you tell me how you tested the spark at the plug end, was it a long screwdriver held against the rocker cover or heavy duty pliers.
Also list what has been replaced as against checked.

cabby


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## joedenise (Jul 20, 2007)

to be certain put it on the tip of your tongue

   :lol: :lol: 

joe


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## tomtank (Aug 2, 2011)

Everything checked and double checked, i have an inline spark plug test light.

There is a very slight bit of play in the dizzy drive but i think it may end up as a problem with the Hall Effect and reluctor ring inside the distributor head, i have a new distributor that should be here this afternoon.


I will post my results 



Tommo


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## BillCreer (Jan 23, 2010)

Still don't understand your reference to "Servo Vacuum Hose"


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## greygit (Apr 15, 2007)

Have you done a compression test?
Gary


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## waggy3 (Jun 24, 2008)

hi 
i dont know your engine but on some enginesthe spark plug fires on the compression stroke and also again on the exhaust stroke.
check the leads and maybe pick someones brains
it is somthing to do with emmisionsfrom the exhaust.
roy


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