greetings from the yukon,

i just finished replacing my thermostat tonight and noticed two fittings on the housing and am curious what they are. neither of them are hooked up to anything and my haynes manual doesn't seem to mention them at first glance.

will having them unhooked adversly affect how my bronco runs?

thanks

see ya

Bob

 

Are you talking about the throttle body? I have heard that the coolant lines running through the throttle body were to prevent a stuck throttle in cold weather.

EDIT- Nevermind my post, I didn't realize you were talking about a '78

 

Could be a universal aftermarket housing that has the fittings in case it is used on a later model truck.

 

the housing has the ford oval on it. the fittings look like vacuum type devices, one has a sort of tree with about four little branches coming off, one of which is blocked by a rubber hose with a bolt in it.

i'm going to try aand take a couple of pictures of it.

see ya

Bob

 

ok,

so, if a picture is worth a thousand words i've just added 3k worth to my gallery showing the housing. the blue fitting has two ports. the truck is new to me and there's lots i don't know about her (for instance finding out the hard way that the air cleaner is from a '75 torino, a fairly uncommon filter by the way )

anywat have a check and see if these help id'ing what these are.

see ya

Bob

 

It looks like a temperature sensitive vacuum control valve of some sort. Is that the original engine for the 78 or did it come out of a 79? It is probably emissions related but I didn't think that arrangement was on the 78 and added in 79. The blue single one may be a temp sending unit. I am working from memory here and may be off on this.

Good Luck.

 

There is a 78-79 second generation Bronco club at bigbronco.com and if noone here knows what it is those guys & gals may. Hopefully the moderators won't me for mentioning this site!

 

Hey,

as far as i know it is the staock engine but i suppose someone may have used a different housing on it. i'll check out your tip, thanks for the input

see ya

Bob

 

I suppose its also possible that your rig was built late in the year and Ford fitted it like a 79.

 

rlh was about correct. It's a temperature controlled vacuum switch for the EGR valve. It was to make sure the EGR valve was only operational when the water temp was over 160 degrees. The one on a 78 F-150 I once owned only had three ports. One went to manifold vacuum, one went to a storage canister and the other went to a vacuum amplifier. The amplifier had two ports, one of witch went to the EGR valve.