Strange clicking when I put the car in gear

[FiatSparky]

It's weird......I hear a "clicking" like an electrical switch when I go to put my Fiat in any gear. It's right in the beginning of the shift and sounds like it's coming from under the dash on the passenger side (in the mess of wiring under there).

Anyone know what this may be?!?

[mdrburchette]

What year car do you have? It may help determine what could be clicking.

[FiatSparky]

It's a 79

[mdrburchette]

Have you dropped your relay panel down to see if you could pinpoint which relay is clicking? The 79 has a nice, neat little panel, unlike my 72 where you have to disassemlbe the entire dash to get to anything.

[FiatSparky]

I'm going to check it out first thing in the morning.....anywhere I can find a schematic of the relays (what they are and positioning) ? I can't think of what for the life of me would be hooked up to the shifter..........

[mdrburchette]

I can't either, unless it has something to do with emissions, but why would anything like that be on a relay? Here's a link to Brad Artigue's wiring diagrams for your 79:
http://www.artigue.com/fiat/wiring/Wiring_1979_1980.pdf

[mdrburchette]

There is a diverter valve bypass relay but I'm not familiar with how a diverter valve works.

[majicwrench]

Diverter valve directs air from the air pump to either the engine, the convertor, or it just dumps it.

[danaspider]

Does the clicking go away when the car is warmed up? On my 79, years ago, there was a clicking type sound when the car was cold. I found that the clicking was actually a small exhaust leak from the exhaust manifold. Tightened it up and noise went away.

Just an idea

[boogiedude]

I have the same clicking in my 78 when going in and out of gear. It's definitely some kind of relay/electrical switch. It doesnt bother me enough to actually trace it though. I can sit there and move the stick in and out of gear with the key switched on and the car not running and it'll do it consistently

[bradartigue]

It is most likely the thingy that keeps the throttle open on deceleration. It is a barrel mounted to the firewall and near the carburetor, it has an air inlet and some wires running from it. There is a solenoid on your carb (well, I think there are two of them, 3rd and 4th gear) that trips the thing to stay open.

I'm not sure when they stopped putting these stuff on Spiders; the FI Cars don't have it. It is a good candidate for chucking in the trash, pure emissions-related garbage that never really reduced any emissions at all. The reason they don't show up so much in the wiring diagrams is they were USA only. You can get some supplements to the shop manuals that show how they are wired up; especially in the 1970/71/72 supplements.

[mdrburchette]

I think I've still got that little thing on the fender well of my 72 even though I don't use it anymore.

[majicwrench]

Little thingy on firewall is there for a reason. Helps prevent pop bang pow on decell. Smoother shifts.
Does not hurt anything. No reason to remove it.
There is no soleniod on carb that trips it to stay open.
Mine on my 72 works wonderfully.

[mdrburchette]

Mine was disconnected after installing dual carbs.

[bradartigue]

Oof - my mistake on the solenoid - it isn't on the carb, they are installed in the transmission. And I'm not sure solenoid is the right term anyway. When you shift into 3/4 it the linkage presses these switches and they activate that idle air controller. It uses manifold pressure to hold the carb linkages open. Not a complex system but the transmission mounted parts live a pretty rough life.

Most of the "A" Webers have the mechanism for this thing (DHSA DMSA ADFA ADLA ADHA) if you want to use it.