Cold start misfire on my 2F (1 Viewer)

[HemiAlex]

I've got an issue where once the truck is first started in the morning or becomes cool, it will "pop" once as a misfire on the first real tip in of the throttle.

-It wont do it more than once as long as I'm driving in that session. It the engine undergoes a hot restart, it will not pop. It doesn't effect driveablity aside from that one moment. The truck idles very smoothly.

It pops, I back off and accelerate normally and move on. I have to wonder if maybe it is my distributor not vented correctly and building up pressure overnight or after sitting. I remember it being a bigger deal than I would have imagined.

Here's what I've got-

2F, 284k refreshed head and valves adjusted. 140psi on all cylinders. Running 93.
Completely desmogged.
Carb fan works.
Burns a little oil which is to be expected but my rear main seal is leaking also.
No exhaust or intake leaks. New Exhaust all the way back.
Trollhole carb, timing still at 5*. Need to move to 9-10*
Denso Cap, Rotors, Wires, Plugs and new OEM ignition coil.
,
The truck runs great, accelerates about as good as it can. Averages about 12 city and 15 on pure highway mileage.

 

[NeverGiveUpYota]

Timing. Seems everything thread and I've read an absurd number on distributors, dieseling, ect all lead to advance or retard of timing. But I've only been at this a short time so don't hold me to it.

 

[klinetime574]

I have timing set to stock (7 degrees), full desmog, rebuilt carb, running 87 octane. Other than a high idle which I dropped with the "speed screw" (not sure if exact lingo, on the firewall side of carb pointing upward to the driver side) my 60 runs fine. It might backfire every now and then, that just means its happy.

How many inches of vacuum does it pull at idle? 21 is a good number from what I have read. I'd adjust the timing to stock and go from there. I originally tuned my carb while watching the vacuum gauge and idle speed. (650rpm with AC off)

 

[Spike Strip]

It's prolly 'popping' cuz there's un-burned gas going down the tailpipe when you start.

You may have gas pooling in the intake when it sits.

RFG is not friendly to carb'd cruisers.

 

[HemiAlex]

What's rfg?

It was pooling fuel with the aisin carb. It would start and pull raw fuel on a hot start.

Driveability at operating temperature is excellent, and it's the most fun slow truck ever to row through the gears in. It almost makes me want to ignore it but I want to rule out that there isn't a critical flaw that I'm missing.

 

[HemiAlex]

@Spike Strip gotcha on the rfg.

I ran about four tanks of ethanol free while on my road trip, it completely changed the truck. Felt like 25 hp gained.

 

[Spike Strip]

Before you start the truck, check the sight glass on the carb, if it's empty, check down the throat of the carb and manually open the valves and see if fuel is still pooling on the intake floor.