munzy42
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help. 93 maverick 4.2lt. Duel fuel, carby. Pertronix lobe points replacement. Gt40 coil (without resistor type). Issue I have is miss developes after 15 - 20 min, once everything gets hot. Doesn't matter whether its on gas or petrol, gas is worse than petrol once problem starts but truck runs sweet on gas or petrol to start with . I've fit a new coil, cleaned terminals, checked/cleaned plugs, I'm getting 11.3vt at + on the coil and earth lead on distributor base when running at idle ( tested when problem pressent) . Today was a cooler day and magically the truck ran good for the whole 25m drive home. ( slight miss at take off if idling at lights for a minute or two but then OK)

When it played up yesterday I cracked it and pulled over to test power ect, sat in the truck reading the manual for 1/2 hr with engine off then it ran fine for 15 min again.

think its a spark issue because it happens on both fuels.