little6872

hi chaps got a mk2 escort with a problem and its doing my head in just put a second hand engine in its a crossflow the problem is when i start it up it wont rev and is missfireing but when it warms up a little bit it will rev but it still seems to miss when on tickover if i go to pull away it misses i have to give it loads of revs to pull off and to top it off the coil is getting red hot i cant even touch it its so hot ive replaced every thing on it the points/condencer coil all the leads carb fuel pump distributor cap rotor arm only thing yet to change is distributor but this coil is doing my head in getting so hot im not a mechanic but can do bits and pieces ive set the timing with a strobe light but with the missing the timing mark on the crank is all over the place any idea what could be causeing the problem any help would be great and dose anyone have the points gap ive set them at 15 thou is that right and i have changed the plugs as well

gingerturbo

iTrader: (2)

Have ya checked all you live and earth terminals sounds like a shorting earth to me, also have ya tried a different coil

little6872

hi its just had a brand new coil as the old one was getting hot so bought new one thinking that the old one was ka-put would a bad earth on the engine cause it i havent checked the earth

gingerturbo

iTrader: (2)

Yeh if its loose/shorting out/or has to much current going through it will get hot, also check your alternator as that could be sending a current through ground

JFB Tech

Not sure if they did it on the MkII Escort but a lot of Fords ran a 7 Volt coil fed through a resistance wire to drop the Voltage down. When cranking, they were fed with 12 Volts to boost the spark. If they run 12 Volts all the time then the coil will overheat. Would be worth seeing if the coil feed wire has been replaced with standard wire.

martysmartie

iTrader: (1)

This is worth a check, this is known as "Ballast" ignition.

Yes a bad earth engine earth would cause it to heat up and cause problems elsewhere as well.

Martin

gingerturbo

iTrader: (2)

^^^oh yes the old ballast resistors^^^ forgot all about that

little6872

hi so if its running at 12 volts through coil wire how will i solve that problem and would this cause it to missfire

gingerturbo

iTrader: (2)

Firstly work out if your loom/electrics are running off 6/7v or if its bin converted to 12volts, and also is your coil a 12v coil or 6/7v

martysmartie

iTrader: (1)

There is a resistor fitted in the loom which reduces the voltage to 9V, when cranking, as said, there is an additional feed to assist starting, once the engine is running it reverts to the 9V feed.

If you have such a coil you will need to add a 'resistor' to the loom, yes it will also destroy the coil.

Martin

little6872

as it happens i have another distributor and it has a black thing on it which the wire from the coil gose to at one end and a wire coming out the other end to the points could this be a ballast just the distributor thats in the engine dosent have one of these on it

martysmartie

iTrader: (1)

No, the resistor reduces the supply.

Martin

gingerturbo

iTrader: (2)

Sounds like the ballast, a lot of the older cars use to have 2 bullet connectors plugged into the square ballast, try using that dizzy to see if that makes a difference otherwise wire in a resistor

little6872

hi could i can buy a ballast resistor off ebay could i just buy one and fit it in the 12volt feed to the coil if so do you know what 9v works out in ohms as i can get a 1.5 or 1.6 and how would i get the 12v when cranking it over to start

martysmartie

iTrader: (1)

It depends IF you have a 'Ballast coil', which should be marked on it. If you don't there isn't a problem, providing that has a 12V supply.

If you do, then yes to keep the current coil you need to add a resistor, I don't know the value offhand but from my GCSE electronics, I remember there is a calculation you can do.

The feed needs to be taken from the starter.

Martin

gingerturbo

iTrader: (2)

I'd say the 1.5 ohm resistor and wire it in the ignition feed to the coil

gingerturbo

iTrader: (2)

^^^ohms law^^^ V=iR

Cossie Sean

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Cossie Sean

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little6872

well thanks for all your help guys will let yous know how it goes will check it all out and see what ive got thanks again

gingerturbo

iTrader: (2)

Quality