When servicing my 1986 Ford Bronco, 5.8L 351 Winsor Motorcraft/Holly 4180 4bbl carb, Original owner, 173,000. I noticed that the potting material from the electronic ignition module that sets on the inside drivers side fender well has apparently overheated. It still starts, runs as always had, but my gas milage has decreased from about 12-13 highway down to 10. I was thinking the carb was leaking internally. Could the module still work but cause decrease in milage, due to some internal damage??

Its a cheap fix, 20.00 for a BorgWarner module from Advanced Auto. (others better????) Suggestions requested

Any comments suggestions, other than just replace the unit, I am wondering about its performance vs gas milage.
Bronco is only used about 4000/year to tow boat to park, an run short trips,some highway trips.Can't afford to drive it much anymore but would like to squeeze all I can out of in the way of MPG.

Thanks Bob

P.S.

I did read somewhere on the board about the silver ignition modules vs something else, but was not sure what the writer was implying? High failure rate/poor performance. What are the other alternative units as to a replacement.

As an update, I just recalled that I had the Alternator replaced not too long ago. The wiring harness on the Alternator had shorted and burned. Replaced the Alternator and Pigtale connector. Maybe that is when the Electronic Ignition module overheated due to short at alternator??

 

Steel . i dont think the module has anything to do with your mileage, 10mpg sounds about right with that yr truck and engine.I know it may vary depending on temperture and conditions.I have a 1985 f-150 4 x 4
with the 300cc 6cylinder and i get 13. In the early 90s there was a recall on the electronic modules, actually mine didnt go out it just quit because of heat (as u imply) driving down the road one winter night it quit later it cranked and i made it home 5 miles . Next am i took out the chiltons and started replacing the cheaper parts -fuel pump plug wires etc. Finally i took it to a mechanic and he saved the module u could see the burnt spot and wires.The truck would still run but would die at odd times. Is it the original?I would definatly replace that module with a Ford brand Good luck TR

 

Steel . i dont think the module has anything to do with your mileage, 10mpg sounds about right with that yr truck and engine.I know it may vary depending on temperture and conditions.I have a 1985 f-150 4 x 4
with the 300cc 6cylinder and i get 13. In the early 90s there was a recall on the electronic modules, actually mine didnt go out it just quit because of heat (as u imply) driving down the road one winter night it quit later it cranked and i made it home 5 miles . Next am i took out the chiltons and started replacing the cheaper parts -fuel pump plug wires etc. Finally i took it to a mechanic and he saved the module u could see the burnt spot and wires.The truck would still run but would die at odd times. Is it the original?I would definatly replace that module with a Ford brand Good luck TR

 

Thanks for the update Black Ford XLT. I did replace the module. I guess I was just dreaming of higher mph, hoping that the distributor was not advancing/retarding properly. I picked up a BorgWarner unit, only $20, odd thing the older unit, seemed to work, however, I now notice that it will start much easier, it was not doing so good on starting the first time of the day, after that, almost on first turn of engine it started. Now with the new unit, It starts very easy the first time of the day. It was almost like with the old unit, it was flooding on first start of day.

Its an old vehicle, nearing its lifes end, but has been extremely reliable. Very little rust, still looks extremely good, painted once in 99. Everything still works, including the AC all original, which I need here in Fl.

Thanks Bob