Noticed, that the fluid level in my transmission is low-ish. I'll top it up and see what happens.
Is this all somehow connected?
Thread Starter
Pro
Joined: Oct 2006
Posts: 542
Likes: 3
From: Vilnius, Lithuania
Is this all somehow connected?
1973 454 automatic with bigger cam (not exactly sure about the specs). Headlights are going up/down quite slow. Engine does not idle properly, there is always a need to keep it revving a bit, otherwise it dies. Also it is very difficult to engage reverse gear, especially if the car is sitting on incline surface.
Is this all caused by insufficient vacuum? Eg. not enough vacuum for quick operation of headlights, not enough vacuum for distributor vacuum advance. I assume, I could try switching distributor advance vacuum from port in the carb to port in the manifold? But what about the gearbox, is this problem related to vacuum?
Any hints would be very much appreciated
Is this all caused by insufficient vacuum? Eg. not enough vacuum for quick operation of headlights, not enough vacuum for distributor vacuum advance. I assume, I could try switching distributor advance vacuum from port in the carb to port in the manifold? But what about the gearbox, is this problem related to vacuum?
Any hints would be very much appreciated
Melting Slicks
Joined: Jul 2010
Posts: 2,503
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From: McGrady NC
St. Jude Donor '15-'16
The cam could very easily cause all sorts of vacuum issues, but I would be sure to check all the system for leaks, too. That could also worsen a weak vacuum condition. The transmission problem is not vacuum related. I'd be sure to check the fluid and possibly service the transmission (new filter and fluid) before going much further. That is assuming it is not a mechanical problem. The shifter to transmission cable may need attention. So much to check.
Melting Slicks
Joined: Apr 2002
Posts: 2,337
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From: Norfolk VA
It would be good to know the specs of the cam. A cam too large could affect the headlamp operation. More importantly, the brakes. How do the brakes perform? Does the transmisson shift smoothly. Is the vacuum modulator operating properly? Have you have any loose, missing vacuum lines? Let us know.
Thread Starter
Pro
Joined: Oct 2006
Posts: 542
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From: Vilnius, Lithuania
Ok, so it looks like there is no connection between not going into reverse and idle/headlights.
Race Director
Joined: Apr 2007
Posts: 11,152
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From: South Western Ontario
It sounds like you need to inspect everything for leaks and then do some tuning on it. Then see how it works when the timing and carb setup are optimized.
Do you mean it's hard to engage reverse because it stalls?
Do you mean it's hard to engage reverse because it stalls?
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Thread Starter
Pro
Joined: Oct 2006
Posts: 542
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From: Vilnius, Lithuania
I topped up the transmission with fluid and then closely inspected transmission vacuum modulator line. The rubber bit at intake manifold end was rough and I suppose it was leaking. So I replaced it and also switched distributor advance from ported vacuum at carb to manifold vacuum. Now engine idles much better and engages into reverse (with a second of delay). So afterall it looks like my transmission issue was vacuum related. Not sure, why some were so sure that there is no relation between vacuum and transmission?
Instructor
Joined: Mar 2013
Posts: 215
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From: Sunshine Coast Qld
I topped up the transmission with fluid and then closely inspected transmission vacuum modulator line. The rubber bit at intake manifold end was rough and I suppose it was leaking. So I replaced it and also switched distributor advance from ported vacuum at carb to manifold vacuum. Now engine idles much better and engages into reverse (with a second of delay). So afterall it looks like my transmission issue was vacuum related. Not sure, why some were so sure that there is no relation between vacuum and transmission?
