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Hello I have a 1990 f150 with a 5.0. I’m trying to figure out what this is and where does it go. The hose on the left side I just put on there. The hose was just laying under the hood when I bought the truck. It looks like it fit there so I just hooked it up to one side, but I can’t figure out the other side. Thank you for any help.
Looks like somebody disabled some of the emission control hardware..Do you know if there is an air pump on the lower passenger side front of the engine?
Hello thank you, yes, there is a brand new smog pump. All the vacuum lines are connected. That is the only piece that I have no idea what it is lol it’s driving me crazy. I can’t find anything
Does that hose come from one of the connections at the air pump?
Not knowing how much was altered, , take a look at the catalytic converter and see if there is a port blocked off or any port at all for that hose to connect to..
On that engine , the pipes from the engine to the converter and the converter were all one piece and as I recall the replacement cost was around $600.00 years back.
Many folks that did not understand the system chose to either remove all the components or by pass them.When working properly , they did do the job..
There were diverter and by pass valves that were engine temp and vacuum controlled.
Are there any pipes at the engine head going into the exhaust manifold cut off and bent over ? If so they thought they were doing well, lol.
Thank you. Everything for the emissions is there. New smog pump, egr valve all new vacuums hoses. The tube that goes to the cats is in good condition. The pipe to the egr is not bent. The picture that I posted, there is a hose going to it from the smog pump. I just Dont know where the other side is supposed to go.. thank you
Thank you. Everything for the emissions is there. New smog pump, egr valve all new vacuums hoses. The tube that goes to the cats is in good condition. The pipe to the egr is not bent. The picture that I posted, there is a hose going to it from the smog pump. I just Dont know where the other side is supposed to go.. thank you
I just looked at the picture I posted. I circled it in red. The hose on the right side goes to the smog pump. The one on the left I just found laying there so I assumed it got hooked up to the other side.
I had to delete one of my posts because it was not for a V8 engine, but for a 4.9 engine.
On the V8 engine there was a thermal vacuum sw that provided vacuum for the thermac system..
There was a diverter valve that when the engine was cold, would direct air from the air pump to the exhaust manifolds to help provide extra oxygen to the exhaust.Once the engine temp reached a certain point the ECA opened the valve or vacuum and directed the air from the pump now to the converter to clean up the exhaust..
These valves were known as TAD, thermal air divert , and TAB, thermal air by pass. To prevent backfire in the exhaust the TAB would send the air from the pump up to the air cleaner at the top of the engine.when decelerating and coasting.
Hope This winded explanation helped. I should be able to find a diagram of the air pump hose routing. , Any day now ,lol.
If you see funny looking circular metal valves on metal piping, they were termed anti backfire valves to protect the air pump.
If you type in Ford Thermac system, there are better explanations,
1990 f150
