Replacing the one on the left with the one on the right. The new "solid state-(no hole)" technology is more reliable and is certainly more aesthetic A friend turned it on a lathe for me. If anyone is interested in one, PM me. You can defeat the original with the wire jumper at the expansion tank or bypassing the electro-valve vacuum switch with the hose; but if it fails, it is in the in the open (high revs) position. Image Unavailable, Please Login
Since only US cars had this widget, the idle speed should be the same as non-USA injected 308s. I am going to mod mine also to lower the ridiculous cold idle speed, but I had something else in mind. I wonder if Art's "pipe" will pass CA smog. I don't know if testing this item is on the California test regimen or not.
I have just removed my cold start valve but: 1) I was told to plug those holes (in the rubber pipes) after removing the cold start valve. So what is the right thing to do? 2) What about the tiny rubber line which goes from the top of the cold start valve to the solenoid valve: should it left open? Thanks for your attention Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
You must plug the holes in the large hoses - this device is an air bypass and when you remove it, outside unfiltered air enters into the circuit. The small tube at the top is a vacuum line. It goes to a solenoid that turns the vacuum on/off with an electrical signal from a switch sensing the water temp in the coolant expansion tank. (at least on my '83 QV). The most common way to defeat this is to bypass the expansion tank switch - connecting the two wires at the switch together - preventing the solenoid from turning off the vacuum to the bypass device. A possible problem with this fix is that a vacuum leak to the bypass valve or a bypass valve failure will leave the unit open and raise the idle. So the most complete fix is to block the large hose openings and block the vacuum line that goes to the solenoid from the plenum so that you have no vacuum leaks. This circuit was to raise the idle to heat the cats faster to meet some USA emissions. I believe it went away in '84 when the lambda injection system was implemented. I hope I am clear.
Thank you for your prompt answer. 1) I understand I have to plug the holes in the large hoses (I didn't catch your "solid state" bypass was actually a bar and not a metal pipe) 2) If I am going to block the vacuum line between the plenum and the solenoid valve (to avoid any vacuum leaks) I do not see any reason why not removing also the solenoid valve and simply plug the hole in the plenum. Am I right? Have you removed the solenoid?
Yes - the solenoid is removed as part of my engine beautification project Just be sure the plug the vacuum line going to it. Art
A vacuum comes from the forward side of the intake plenum through the solenoid and to the cold-start valve. The valve gets a vacuum to close the valve when the engine warms. Another way to defeat the valve is to just connect the plenum vacuum line directly to the top of the valve thereby bypassing the solenoid. The test is done with the engine hot, so the system would not be tested for function. The car might fail the visual inspection if the technician knew exactly what s/he was looking for.
