What gives? My 74 had EGR, but I took all that crap off (no emissions in Texas for cars older than 78). Mine only had (has) one line. What would happen if I plugged it? Also, I share one vacuum source at the rear of my intake manifold (Edelbrock Performer 289, I know, I should have gone with the Air-Gap!) with the transmission and my heater switch. Just put a T in there and let er rip. Should I hose it differently? Everything seems to have been working like that for the past two years.
i was just offering a sugestion....i know and you know....but somebody could have hooked it up because they didnt know what they were doing?? simple suggestion....sorry
Wasn't jumping your case. Just informing. No harm meant. As far as sharing w/ a T in the back of that 289... it's fine. I've done it, and seen it done a lot. If you simply blocked off the vacume line to your transmission w/o hooking it up to a source of vacume (the engine) then you wouldn't have third gear in a C4 or C6 transmission.
If you're going to a non-EGR setup, just get rid of the extra line altogether. That's what I did on my '73...
Not all EGR cars have 2 lines. It just depends on the year and application. The modulater adjusts shift points based on engine vacuum, which is an indicator of load. The ones with two lines probably work the same as dizzys with two lines. One is probably straight manifold vacuum, and one probably goes to a thermastatically controlled switch which adjusts vacuum signals based on operating temp. No harm in leaving it connected, and I have never heard of harm unplugging one. My car is a 77 with California emissions, and I have the single line one from the factory. They don't get much smoggier than a 77 with a VV carb and Cali. emissions. (All long gone, thank god)
It's been so many years ago (1991 or '92) that I don't remember. All I know is that I removed any and all unnecessary vacuum lines for a more simple and less cluttered engine compartment. Somehow, I discovered that I didn't need 2 lines for the tranny. Wish I could remember but I'm starting to get old ( was only 29 when I first discovered this site). I have one vacuum line to the tranny and one vacuum line to the distributor, and that's it. Got rid of all the other B.S. ...
