BritishV8 Forum

General Category => MG Sports Cars => Topic started by: edwin68 on April 13, 2015, 05:59:42 PM

Title: 81 mgb with a 91 3.9 land rover engine stalls when it gets hot need help
Post by: edwin68 on 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
Title: Re: 81 mgb with a 91 3.9 land rover engine stalls when it gets hot need help
Post by: BlownMGB-V8 on 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
Title: Re: 81 mgb with a 91 3.9 land rover engine stalls when it gets hot need help
Post by: edwin68 on April 13, 2015, 08:32:18 PM
I will look into that thank u jim
Title: Re: 81 mgb with a 91 3.9 land rover engine stalls when it gets hot need help
Post by: 88v8 on 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
Title: Re: 81 mgb with a 91 3.9 land rover engine stalls when it gets hot need help
Post by: edwin68 on 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
Title: Re: 81 mgb with a 91 3.9 land rover engine stalls when it gets hot need help
Post by: bsa_m21 on 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.
Title: Re: 81 mgb with a 91 3.9 land rover engine stalls when it gets hot need help
Post by: ex-tyke on 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.