When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So I replaced the alternator yesterday and one of the 2 small tubes right above the alternator came out (tight fit) It is about 10 inches long and attaches somewhere way in the back. I plugged the tube but I figure I probably have some type of vacuum leak. I drove the car and it runs strong- no idle or hi rev problems. Any ideas what function the tube controls? At least I have 14 volts now but I'm not looking forward to removing that alternator to get access in the back, Thanks
Getting the manifold back in without pulling out those stupid tubes can be a hassle...make sure they're not hung up on anything before you start moving the manifold back into place.
If it's the one marked A/B in DBJoe's diagram, it goes from that control solenoid back to the intake tuning control valve. You won't notice a huge difference when it isn't working.
When mine wasn't working it was because the electrical connector was off the solenoid, so I got a code. When I plugged it back in, I definitely notice the difference. It should operate the flap in the intake at around 3,250 rpm.
Before I realized it was electrical, I was able to work my hand back in there and check the vacuum line, but as you can imagine I had to take a couple of things off.
Why didn't I check the electrical first? Funny story - something else was plugged into it, so it looked fine. That was the real problem. The electrical for the tank vent valve was plugged into intake tuner valve solenoid instead, and the wire for the tuner valve solenoid was dangling down the side of the engine. So I was getting a large evap leak error because of the tank vent valve, and an electrical error for the tuning valve.
EDIT: Found a description elsewhere that SEEMS accurate (I was off a bit with my 3,250 guess): Tuning flap not actuated from 700 to 3120 rpm and from 5120 rpm .
Tuning flap actuated from 3120 to 5120 rpm , if the throttle is also more than 30 % open at the same time.
Last edited by Emefef; 08-24-2022 at 05:42 PM.
Reason: added info.
Thank you for that info. Since it's a performance thing I will probably wait and see how it drives for awhile. I use to be a mechanic in collage but that was 50 years ago.
08-24-2022, 03:39 PM
Anyone know what this tube does?
