Prior owner removed the Stromberg carbs on my '73 E-Type OTS and replaced them with SUs. All emission control equipment and other vacuum connections were removed as well. Fortunately I acquired the original Strombergs with the car. I refurbished the Strombergs and have reinstalled them. Also, I was able to research and reconnect nearly all of the vacuum control lines, and the basic fuel evap emission controls. What a learning experience! The good news: it was an immediate and very significant improvement in performance, starting, drivability, and the various odors emanating from under the bonnet and the exhaust. It even sounds much better. Win win win.

Ok, to my question: I had to source new air cleaner temperature sensor units. I want to reinstall them to improve cold performance (and for originality). The originals were missing, but I’ve figured out that they were the same as AC Delco part #6484242 used in many GM cars of the era. The questions is: where on the engine do they connect for their vacuum source? The manual is not helpful because it presumes that when the part is removed, the mechanic will take note of where it is connected. The red arrow in the first image points to the vacuum line in question.

My guess is that on the right-hand side it connects to the vacuum tap on the front intake manifold, and on the left side it connects to the vacuum tap on the rear intake manifold. See the red circle on the second image to see the taps I’m referring to.

Am I correct?

Thanks as always for your help!

Rick

 

My '73 has all the original smog equipment so I can check the vacuum line routes for you. Unfortunately I'm not going to be at the car for a few days but I'll get you an answer eventually if someone here doesn't chime in first.

 

Rick - I checked my car and you are exactly correct. The vacuum line on each side runs from the nipple on the intake manifold to the thermo switch in the inside center of the air cleaner housing, and another hose runs from that switch to the front of the air cleaner intake horn. It's the same on both sides except for which intake they're connected to. You likely know this but to confirm, the other intake nipple on the LH intake connects to the gulp valve and intake nipple on the RH side is connected to the vacuum switch at the end of the coolant rail at the right rear of the engine. It's obviously important that all four vacuum lines from the intakes and all the rubber hoses connected to them are properly connected or you'll get a lean mixture, something that I suspect many mechanics have missed and put down to being the fault of the strombergs. I still have the full emissions set up on my car (I'm a bit of a nut about keeping things original) and it runs really well. Quick starts hot and cold, idles well, and no stumbling on acceleration. It really pays to make sure all the vacuum lines are properly connected and the rubber hoses in good shape.

 

Fantastic - thanks so much for the confirmation! Love to hear about an original car. Yes, I had already figured out where the other two manifold ports connected. When I first got the car, everything had been removed and the PO had simply patched the front and rear manifold ports together with a short vacuum hose. Essentially capped them off.

Documentation was available for those other two ports, but I couldn't find anything to confirm where to connect the air cleaner temp sensors. I surmised where to connect them by the process of elimination, but it's great to have confirmation.

As soon as the new temp sensors arrive, I'll be off to the garage to complete the hookup!

Rick