Smog Air Pump - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

sparkyrhett · 11-18-2006, 14:23

Hello, this is my first post and I hope I am in the right place. I just bought a 1991 Ford F150 XLT, 305 EFI, 2X4, Automatic. While inspecting the engine, I found that there is a hose that goes nowwhere. The configuration is: air pump>hose>canister>hose>?. That hose has been cut and I can not find where it should attach to. The pump is sucking air through the hose and I am thinking that it should be connected to the manifold somewhere. I am not a mechanic by any means, but I believe this is smog equipment related. Any advise will be greatly appreciated. I believe this truck was sold new in Gary Indiana if this will help. Thank you in advance

390wagon · 11-18-2006, 16:41

the 94-97 f-350's i work on goes air pump to a valve over the valve cover, 3 hoses come off of it, 1 to each exhaust manifold and 1 to a muffler on the passenger inner fender. if u dont have to go through emissions then i wouldnt worry about it, in my opinion its useless.

jas24zzk · 11-22-2006, 04:12

IF its sucking air, then it probably goes to a filter.
The basic idea of the smog pump, is to inject air into the exhaust ports, to force a burn of on combusted fuel as it leaves the head.

Cheers
Jas

sparkyrhett · 11-22-2006, 04:50

Hello, here is a link to an image of the hose/tube that I am refering to. It is the the corrigated one coming from the left side of the silencer/filter. I hope this better explains my query. Thanks 1983 Ford Bronco Diagrams picture | SuperMotors.net

390wagon · 11-22-2006, 13:55

connects to nothing, when the exhaust doesnt need the extra air the pumps flow is diverted into the silencer and out the tube to atmosphere. the pump is always spinning with the engine so the pumped air has to go somewhere and the passenger fender is as good a place as any i guess. its cheaper for ford to do that then put a clutch on the air pump like an a/c compressor.