Tech specs: 390FE, 2BBL motorcraft carb: hot air choke, vacuum advance. Problem(s): 1) Can't get fast idle on first start. 2) First and second starts will catch then die. 3) If I don't let it warm up, it will hesitate on accel. I'm not sure if these are related issues or not. I think the starting and dieing are perhaps fuel running dry in carb, but then I am not sure why it eventually will catch and keep running. Had the air cleaner off and the butterfly was open when cold. Pressed accel and the butterfly closed all the way, so that seems to work. I played around with the choke: lean/rich but didn't really make any headway. I'd appreciate any steps to walk through to get this worked out.
Close the butterfly, then look at the choke idle speed screw, located below and behind the choke thermostat housing. The screw tip should be on the thickest part of the choke speed quadrant. If you have the carb's tag and give me the number off it, I can look to see if I have that carb's specs listed.
Also while the engine is cold and air cleaner is off loosen the screws on the round black choke housing and slowly turn it until the butterfly just closes. See arrow to + direction. Now make sure the fast idle screw is on the highest position. Before normally starting push the acelerator pedal to the floor once to set the choke. Remove your fat foot and turn the key to start.
I did adjust the choke a bit and richened it up. It's not cold enough for me to know if I really dialed it in, although it caught and died on the first start, then I pumped the gas once more and it caught and ran. I did not see the carb tag anywhere, although there was a number on the side of the butterfly housing. I need to write it down and see if it matches up with Motorcraft which is what I've been thinking this one is.
mite be its the power valve on the front of your carb they leak and you don't see it but when you try to start no gas whats in the bowl cant get motor to stay running letting it die I had a truck with a 390 2v that's what fix mine 69 mustang 390 fix it too mite look at it if all you have done to choke didn't fix it
Yep, I'd read somewhere on my many searches that could be the issue. I've been debating just buying a new carb as the last time I did a rebuild myself it didn't work that great and the price of a new one is not that much. The issue is I am not sure which type it is, Motorcraft or Autolite, since there is not tag. I'll get out my magnifying glass and try and get the number stamped on the side of the body.
There should be a high speed idle adjustment screw. I'm guessing it's an Autolite 2100. http://www.carburetor-parts.com/Motorcraft-2100_ep_422.html
I've looked at those diagrams, but I have a couple of differences. The thermostatic housing does have a mark on it, however if I line that one up with the marks on the stationary part, the butterfly is so stiff, I don't think it would snap shut to choke. At that position it is completely open. The fast idle cam I have has 3 steps on it, not 2.
