Possible Warm Up Regulator Problems on Euro Testarossa

Well...I thought the problem went away, but unfortunately not.

Just swung by the house to throw out some fertilizer on the lawn before this tropical depression hits town; and, out of the clear blue, I hear that buzzing / humming noise again coming from the engine compartment of the TR! So, apparently it is happening off and on either during the day or late evening. This is the first time I've heard the noise since my last post over two weeks ago.

Did some digging around, and have narrowed it down to these two "air valves" (?) -- part "D" in the above diagram -- one is located on each side of the air cleaner next to the warm-up regulators. They both have a wiring connector plugged into them that branch out of a wiring harness -- so they are electrically charged, hence the electrical buzzing noise and vibration upon touch.

I have no idea why these would be buzzing on their own like this when the car is just sitting in the garage without having been driven for a while. Perhaps it's related to the ambient temperature or pressure in the hot afternoon?

This one has me stumped. Any ideas as to what might be the culprit, or what to check out? I felt all the fuel related items, and did not notice anything out of the ordinary. It all seems point to these two inline valves.

Not sure how important these are to the operation of the car. Nearest F-car mechanic is over an hour away, so was hoping to figure it out before having to resort to bringing the car down.

Any further help would be greatly appreciated. Thanks again!

Eric, what is this "stump the experts" ?

The two valves are the auxilary air valves for cold starting...how they could humm or vibrate is beyond me. But if any part of the system which includes the AAV's is on with the key off then I can only think of 2 possibilities...either the FI relays are bad or there is some type of short in the ignition switch or circuit board, that allows the FI system to power up when the key is off.

I would suggest you first have a look at all the plug in connectors on the circuit board, by unplugging, inspecting for any burning, melting, shorting of any type and if nothing is discovered replace the relays for the engine fuel pump & fuel injection circuits.

Try those checks first and let us know if it helps.

Regards, JRV

Thank you, JRV, for the quick reply and suggestions! I will certainly check these items out this evening, locate new related relays as well, and let you all know what transpires.

BTW, where would be the best source for replacement relays? There's a large NAPA down the street, plus PepBoys, etc.

Eric, anywhere that sells Bosch relays should have the ones you need, if necc. pull one call both places and give them the Bosch part # off the housing.

Regards, JRV