I am getting down to a relatively short fix-it list on my 1950 Champion. One of the problems that I haven't yet fixed is a tendency for the car to stall when I commence acceleration. It also has a sort of "flat spot" in acceleration, about one-third of the way through each of the gears. I didn't notice this problem right away when I got the car runing, but it might have been masked by other problems, like my bad old fuel pump.
I have new plugs, wires, cap, rotor coil, condenser. I have rebuilt the carb and replaced the fuel pump, even put in a new, longer (20" long) fuel line from fuel pump to carb to reduce vapor lock (it seems to help). Dwell and point gap are all set pretty right. Timing seems to be in the right range (pings a little at high revs under load) although my timing light went bad, so I can't be sure that isn't part of the problem. I use regular unleaded gas.
A mechanic friend told me to check my vacuum advance by disconnecting it at the manifold, hooking up a hose and sucking on it. If the hose wouldn't draw, the advance would be ok. Otherwise, there is a leak. First time I did that, a small amount of gas came out! (Where did that come from?) I did it again later and just got fumes, and it seemed like it drew pretty hard, but didn't stop drawing completely. Vac. pipe fittings seem to be ok and are tight. Vac. wipers work ok.
Having said all this, I came to the conclusion that the likely culprit of the hesitation is the vacuum advance, aka spark modifier. Trouble is that I can't find a replacement. Not at Stude Intl., not in Cathcarts or Fairborn's on-line catalogs, not on eBay, nowhere.
1. Does anybody have a NORS vacuum advance for an Autolite IAT 4001 distributor (used in late 1950 to 54 Champions, maybe some trucks), or can you point me to a vendor or even know a current part #?
2. Is there a better test of vacuum advance than sucking on the pipe?
3. Any other ideas for the cause of the hesitation and "flat spot" in acceleration?
4. Why is gas in my vac. pipe?
I would appreciate anybody's help with any of the above issues.
Thanks,
1950 Champion 4 Dr.
Holdrege NE
I have new plugs, wires, cap, rotor coil, condenser. I have rebuilt the carb and replaced the fuel pump, even put in a new, longer (20" long) fuel line from fuel pump to carb to reduce vapor lock (it seems to help). Dwell and point gap are all set pretty right. Timing seems to be in the right range (pings a little at high revs under load) although my timing light went bad, so I can't be sure that isn't part of the problem. I use regular unleaded gas.
A mechanic friend told me to check my vacuum advance by disconnecting it at the manifold, hooking up a hose and sucking on it. If the hose wouldn't draw, the advance would be ok. Otherwise, there is a leak. First time I did that, a small amount of gas came out! (Where did that come from?) I did it again later and just got fumes, and it seemed like it drew pretty hard, but didn't stop drawing completely. Vac. pipe fittings seem to be ok and are tight. Vac. wipers work ok.
Having said all this, I came to the conclusion that the likely culprit of the hesitation is the vacuum advance, aka spark modifier. Trouble is that I can't find a replacement. Not at Stude Intl., not in Cathcarts or Fairborn's on-line catalogs, not on eBay, nowhere.
1. Does anybody have a NORS vacuum advance for an Autolite IAT 4001 distributor (used in late 1950 to 54 Champions, maybe some trucks), or can you point me to a vendor or even know a current part #?
2. Is there a better test of vacuum advance than sucking on the pipe?
3. Any other ideas for the cause of the hesitation and "flat spot" in acceleration?
4. Why is gas in my vac. pipe?
I would appreciate anybody's help with any of the above issues.
Thanks,
1950 Champion 4 Dr.
Holdrege NE
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