I assume you are still running the coolant spacer between carb and manifold? Reason I ask is, the gasket between the spacer and manifold is different at the rear. Had one customer on a 64 390 that would not idle, wrong gasket installed. Huge vacuum leak. Bill
carb not removed recently. has been running OK, a little rough at idle. thought coolant spacer was only put on in '65 but, I am new at this vintage Bird. yesterday took it on freeway for a 35 mile ride , and when off Fwy is when this problem started. this '65 has lots of vacuum lines in part for the speed control (cruise control), which I did not use. another real oddity is windshield wipers movement comes via power steering.
Does your 4100 have an air cleaner ?? Look at the top of the boosters, theres some little holes, any debris built up on them ?? Ricky.
Those autolites had a problem with composite floats that would loose buoyancy, at idle the engine would be over-rich and sooty tailpipe, it'd act kinda normal when driving. It isn't common for the float to go bad but it does happen if it has sat for long periods.
while listening / looking for possible vacuum leaks will check carb too. has aftermarket 14" air filter on it. Zdo not want to use any carb cleaner, etc because just painted a lot of stuff while changing plugs, wires, etc
so, today started up motor with aftermarket dropped base housing & 2" filter. but, could hear too much air noise, so put stock original back on to control noise. hissing noise coming from rear area of carb. used WD-40 (recommended instead of starter fluid, etc) to spray on hoses, etc. No change. motor warming up, so shut off. took Lunch break, and started motor, this time touching hoses. hissing changed when I pulled up on hose that goes from manifold fitting at rear passenger side of carb, and sound changed. figured hose bad, went to Parts Store for hose replacement ( Earl's Super Strong rubber hose), and air cleaner flat base. had some new keys made for Bird while in Sacramento. no real locksmiths in area where I live. back home looked at section of hose still attached to manifold fitting to remove. yikes, turns out that fitting is a T. Brake Booster hose on one side, no hose or sign of hose or plug on other end. Wow, so put plug with zip tie on the open end. replaced hose to Booster. But, did not start motor since I was trying to figure out air cleaner situation. stock air cleaner is like a tomb for carb with small inlet for air. these vintage Autolite 4100 carbs are known for gas boiling in bowls when shut off after a warm day drive. many others do this too, not just vapor lock. figured more air into carb & around it should improve this situation. why going with 14". using 2" filter for more clearance from top of air cleaner lid to hood insulation. stock one touches insulation. but, drop base puts lid to close to carb top. flat base puts lid higher than stock air filter housing. too low or tall. tried the plastic carb spacers to raise 14" but, do not seem to work good with this carb. will have to do more figuring this out. maybe a different flat base than one I bought. not a common item to find. of course, this comes up after just being at the Reno Swap Meet. updates later.
did not mean to dominate this thread - to finish up what I was figuring out on '65 T-Bird 390 as stated above - found a 14" air filter base with a mild drop base that works good. also, found out that the manifold brass T that I put a plug on goes to a unconnected line that feeds vacuum to a storage canister and more. nothing easy. attached pics shows most vacuum lines under hood by using green tape - for those of you with only one or two vacuum lines to deal with
BUT !!!.........did you figure out the vacuum leak around the carb ?!! I like to block off ALL vacuum hoses coming from carb/intake and get the engine running light THEN ..check each vacuum component one at a time until all is well. Being California car I guess you can't just block off all non-essential vacuum lines ?!(like fuel carbon canister etc) 6sally6
Nonsense. Nothing manufactured prior to 1976 is required to have any smog equipment present. We have no vehicle inspection here, on anything, ever (except VIN/serial verification).
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