hey guys!!
ive got and 86 f150 and ive got some issues with the right headlight and turn signal. with the headlights off everything works as normal. when i turn the headlights on the right side headlight is dim and the right turn signal indicator stays on in the cab solid. when i turn the right signal on with the headlights on it flashes very slow and random (or at least the indicator inside the cab does live never watched it flash from outside but id assume its the same). i have no clue where to even start with this.

another issue im having is since ive upgraded to a holly 390 cfm with the new intake and headers (4.9l) it seems to cut out when i want to give it gas some times(especially cold). I think upgrading to a more powerful msd coil would be a start and if that doesnt solve it then add one of the msd boxes. whats yalls opinion on this?

 

one more thing about the spark issue. advancing it helps with driving but i cant advance it too much because it afffects starting.

 

The headlight issues sound like a bad headlight switch or the wires that run to the switch behind the dash have melted. I'd check those out first.

Regarding how the motor runs:

Have you plumbed heat to the intake yet? When swapping to a 4bbl carburetor and intake on the 4.9 you have to use water heat to the intake so fuel won't puddle on the plenum. You say it occurs when it's cold, so this leads me to believe that you're experiencing this problem.

Basically, liquid fuel builds up into a puddle, and because the intake hasn't got heat, it'll lay there until you step on the gas. When the throttle valve opens, it draws this liquid fuel into the engine and it can't burn it because it isn't a vapor. That, combined with the fact that it also draws in too much fuel when you do this, leads to cutting out/bogging.

To fix this, you build a fitting that's bolted onto the bottom of the intake where the stock intake/exhaust manifolds bolted together. Then, you tie into the heater core hoses to supply coolant to the intake so that when the motor is warmed up, the intake is heated as well.

This is the only thing that will fix it. You won't be able to tune the motor correctly and it won't run right until you do it.





Photos by AbandonedBronco

 

my problem with creating a plate like the one you've shown is that i had to grind back that mounting point for the exhaust manifold to fit my headers. I could get a carb spacer heater on easy but would that do anything?

 

Search through the archives of the I-6 Forum and you'll find all kinds of information on this....