81 mgb with a 91 3.9 land rover engine stalls when it gets hot need help

edwin68 · April 13, 2015, 05:59:42 PM

Hi everyone I inherited my fathers mgb. It has a 3.9 land rover conversion motor in it and the problem the car has is after driving 100 miles the car will stall and won't restart. I keep going thru coils. Now since I didn't build this and the person who did is no longer with us I was hoping someone out can help me. To me it seems the coil is getting to hot it is current installed on the stock location on the right fender right over the right exhaust manifold. What have you guys done to resolve the heat issue from either moving the coil or in replacing the dist. with a coil build into it. what would be the best way to resolve this issue. Thank you ahead of time any input would be helpful ed

BlownMGB-V8 · April 13, 2015, 06:52:25 PM

Ed, you could relocate the coil and that sounds like it would be a real good idea. Another thing you could look at is the balast resistor. Now some coils are made to run without one so you need to check and see which type it is, but with a resistor it will reduce the current and the coil won't make as much heat. Balast resistors come in several different ratings. The best thing is to match the resistor and coil to a car application that used both.

Jim

edwin68 · April 13, 2015, 08:32:18 PM

I will look into that thank u jim

88v8 · April 14, 2015, 03:12:48 PM

And install the coil so it's upright, not on its side. That way the windings will be permanently immersed in oil.

I second that a ballast coil with a suitable resistor is a good mod.

Ivor

edwin68 · April 15, 2015, 10:38:23 AM

Thanks ivor I plan on working on it on sat won't be able to test drive it till the following weekend being that I have to drive 100 miles to get it to act up

bsa_m21 · April 15, 2015, 11:01:41 AM

Also check the carb (if you have one) for heat transfer. If it gets too hot the fuel will boil and make it very difficult to start. On the advice of Fred key, I installed an isolator and heat shield. Made a world of difference.

M.

ex-tyke · April 15, 2015, 05:30:54 PM

As a check for correct coil application, your model year should have a ballast wire (WLG) as part of the engine/front end wiring - it follows that the coil resistance across the two ( + & - ) terminals should be about 1.5 ohms.

EDIT: Meant to add...... If your coil measures 3 ohm, it's most likely that extra resistance is developing more internal heat which the coil can't dissipate adequately.