I have a 1985 Bronco with an inline 300 that has been rebuilt with a Comp Cam 260H cam, new valvetrain including adjustable rocker arms on screw in studs, guideplates, etc. Intake is an Offenhauser DP with a new Holley 390 vacuum secondary, electric choke. I built and installed the hot water plate heater for around town driveability. Exhaust is EFI manifolds with a Walker two into one back to the stock muffler and tail pipe. I removed the catalytic converter completely. I am running a DSII ignition with a cheapo distributor. Everything worked great, and still does, unless it's less than about 40* F. We are in southeast Texas, so this is only a problem 20-30 mornings per year. It starts right up and runs well when it's warm. When it's cold, it sounds like it wants to start, and if you keep cranking and playing with the gas pedal, it eventually floods. I've tried everything I can think of. The carb is jetted right out of the box, and worked so well that I didn't want to worry with it. I'm happy with the power and driveability of the whole combination, except for not wanting to start on cold mornings.

Does anyone have an idea for me to try?

 

Not enough ZAP from an archaic ignition system would be my first thought. You have tons of great air and fuel flow with that setup (would want an Aussie 240 head for it, personally) but, Duraspark is prone to inexplicable failures to begin with. Heavy air and cold intake walls cause excess condensation and "water down" your mix as it heads for the cylinders on a cold morning. Good strong ignition spark will help cut through it. Hotter and stronger will dry out the air as it gets closer and help expand the air/fuel mixture as it enters the cylinders.

 

Thanks for the input Greystreak 92. What ignition system would you suggest? When I started gathering information for this combination, no one ever mentioned that it would be so hard to start in the winter. Most of the builds I read on this forum and others used the Ford DSII set up and were happy with it. That's why I went with it, though I used aftermarket new parts, not the junkyard pickup parts. I'm thinking of using some heating pads hooked up to the secondary battery system to preheat the intake and help with the fuel atomization. Any thoughts on that?

 

Yeah, that might help too... you say you are running the EFI exhaust so there really isn't the kind of direct heat rise effect that you got with the original manifold that nested under the intake. A lot of folks have good luck with MSD especially their coils. You may be able to get buy with a stronger coil and some really good wires. Ford engines like Motorcraft plugs or Champions. Some of the guys run odd-ball specialty plugs but every one of mine just springs to life when a new set of Motorocrafts start zapping in there. You could try one heat setting higher (than the OEM) on the plugs too if the problem persists. Just watch your operating temperatures.

 

Thanks again, I will try some of these suggestions. I am using Champion spark plugs.