Since putting in my 85 5.0 in my '75 this past april, it's been running great. Only one small problem; after sitting cold, I have to continuously pump the pedal to keep it from stalling. I know the electric choke is working correctly on the 600 Holey because I've visually checked it. The idle and timing are also set to specs. I'm not much of a carb guy, so any advice would help. I'm also using the original fuel pump, could that be the problem?
Sounds like the fuel is leaking out of the bowls when it sits. Does the need to pump the pedal clear up pretty quickly after starting? The bowl gasket is probably leaking onto your intake. If that isn't it, sometimes if it is getting enough heat, combined with low float setting, it can dry the bowl out. If your accel pump is leaking, it can also leak the bowl dry. Do you have puddles on your intake?
Are you using the original 4v intake with EGR? That intake gets TONS of heat from the EGR, if the float levels aren't up to snuff, seems to me combined with summer heat, the bowls could evaporate. If so, I would block the EGR, then use a wood or phenolic spacer under the carb. You can also block off the regular heat crossover under the carb. I always do that myself, but my car is not a daily driver and I live in the south where I don't have to worry about winter warm up.
It's a problem only on initial start ups. Playing with the pedal does cure the problem once it warms up. I don't worry about winter here because there is too much snow around to use it. I always keep it in a closed garage year round.
Is your idle set real low??Hows vacuum signal at intake??Accelerator pump adjusted well??Are you running a real lumpy cam.Do you have it set real lean??
As mentioned, I'm not too keen on carb manipulations. I'd have to check for proper vacuum signal settings, pump adjustments etc. It's the stock cam from the 85 5.0. Thanks for the info.
If your vacuum was real low and you had a radicle cam, I would say some carb modification might be in order.If the motor is stock and mechainically sound I would concentrate on tuning the carb for best Idle,proper float level,accelerator pump shot,best mixture.(not neccesarily in that order though)Good luck,let us know how you make out.
There should be a fast idle adjustment that comes into play when the choke is on. It's a small screw beside the choke housing that adjusts against a stepped cam, makes the engine idle faster by opening the throttle plates a little. When the choke finally opens and you blip the throttle the idle returns to normal. I used to set mine to about 1500 rpm at full choke.
What's the timing set at? If you're using the factory setting of 6* BTDC, then that's part of it. That setting is retarded, litterally............... Set it to 12*BTDC for best operation. Once you set the timing, go back and fine tune the carb again.
