I recently removed the smog pump from my truck. there are vac lines that go over to the dr side. they go into looks like 2 or 3 solenoids in front of the fpr and to the left of the coil. what are they and can they be removed or plugged, the solenoids. I also removed the air tubes that go into the heads and plugged those up.

 

Hmmmm......

 

whats the vac lines for can i just plug them. they all went to the smog stuff. it cant be that important

 

If it is fuel injected the smog stuff is hugely important. You did not say what year and if it is fuel injected but I get the feeling it is from your question. I suspect the oxygen sensor will not give correct information to the computer without the air pump.

I'm sure others smarter than me will be along soon to help.

 

its a 90 5.0 5spd. i had a 92 mustang and it ran fine without a smog pump or o2 sensors hooked up.

 

b4hntn is absolutely right. Arbitrarily removing the emissions equipment will mess with the computer severely. By removing the smog pump you have removed the fresh air injection to the cylinder heads. This is the point at which the necessary oxygen is added to the exhaust gasses for the EGR system to work properly. Without the air injected into the heads the O2 sensor will NEVER get the correct readings from the exhaust and will therefore NEVER send correct information to the computer. This keeps the computer from ever properly adjusting the fuel air mixture. Without being able to control the oxygen flow into the EGR system the computer will assume a "worst case" scenario leaving the truck to run extremely rich because the O2 sensor isn't getting enough oxygen flowing past it. And before you can ask, no the sensor cannot be adjusted. It is a chemically-driven comparator sensor that takes its comparison readings from the side of the sensor that is OUTSIDE the exhaust pipe and compares it to the readings from the inside.

Of course your Mustang "ran fine" without all the emissions equipment connected. Once the computer loses enough input from the sensors and it cannot control the system it drops into limp mode which is basically a "close counts" set of functionality parameters. This allows the engine to run as well as it can under most circumstances. High humidity and high air temperatures would cause occasional misfires at start-up but otherwise limp mode is undetectable unless you want your engine to run optimally with the computer actually controlling the engine for optimal performance. The problem is, you lost fuel economy, burned spark plugs faster, belched more crap into the air than you should have and overworked the injectors because there is no adjustment capacity on ANY of the operational parameters. Yeah, it still runs because in limp mode its supposed to "get you home" so you can fix the problem there rather than on the side of the road. The problem is the efficiency of the system in this mode takes you back to about the mid 1950's in the evolutionary chain of internal combustion engine performance.

By the way, the vacuum lines, yeah, they are just there for the TAB and TAD solenoids to control the opening and closing of the diverter valve which in turn controls flow of fresh air from the smog pump to the heads and the catalytic converter. But without the smog pump you might as well leave the lines to hang or better yet, remove them and let the computer open and close the TAB and TAD solenoids trying to rectify the lack of O2 sensor information thereby generating MORE fault codes in the computer. This way you will have intermittent vacuum leaks on top of the critical situation created by removing other integrated emissions equipment.

 

im not doubting your knowledge but i see 9 and 10 street cars sec cars with no smog pump and some dont even have o2s hooked up. how does that work?

 

50+ years ago homes had two screw in type fuses. If one blew from an overloaded circuit a higher amperage was sometimes used. If it blew some would place a penny behind the fuse. It may have worked for awhile. Sometimes it caused a fire. The point is they modified the design.

There is a reason for the smog pump system. Lots of automotive engeneering went into the design. Why modify it?

 

Just plug them with a couple of bolts.I left my o2 sensor and egr hooked up and removed all the lines from the air pump.I gutted the pump and sealed it up and used it as an idler pulley so i could retain the original belt size.I blocked the back of the heads and plugged the hole in the exhaust.I had no problems with this setup.This was a weekend campin'/wheelin' truck not a D/D.In my opinion the emissions set up was a joke in this era.

 

graystreak92 wrote:
"By removing the smog pump you have removed the fresh air injection to the cylinder heads. This is the point at which the necessary oxygen is added to the exhaust gasses for the EGR system to work properly. Without the air injected into the heads the O2 sensor will NEVER get the correct readings from the exhaust and will therefore NEVER send correct information to the computer. This keeps the computer from ever properly adjusting the fuel air mixture. Without being able to control the oxygen flow into the EGR system the computer will assume a "worst case" scenario leaving the truck to run extremely rich because the O2 sensor isn't getting enough oxygen flowing past it."

Then how does a 02 sensor work without a smog pump. 90 bronco II w/ 2.9 & 96 bronco w/5.8 both non smog pump equip from the factory.

Back when I worked for a Ford Dealer and went to a emissions seminar, the class got into just what a smog system did. What the class uncovered was this, (with a Ford Tech) In short The EPA set standards that the manufacture couldn't meet. Thus the smog system pumped outside air into the exhaust system to dilute it so it would pass emissions out the tail pipe.
So your not really pumping any more crap into the air then if you were to keep the pump & system. But by removing the pump you are removing a pulley that's taking horse power to turn it, thus your saving hp & fuel. However in some states you need the smog crap to pass the state inspection.


Keep Em' Twistin'! Bob B.

 

Mac 91 , the smog pump ( emissions controls)are added for a reason . Before introduced and mandated it was determined engine combustion exhaust produced 60% of the total emission pollutants. Automobile pollutants was the third major source of air pollution .Technically (Twisting wrote:thus the smog system pumped outside air into the exhaust system to delete it to pass emission out the tail pipe but actually its more complicated than that. Sure air is added into the exhaust , but for reasons .Try reading about emmission control. Grey streak is correct about running rich maybe not today but in high humidity or higher temperatures .you may experience back firing ( rich conditions) I know ive unhooked my air pump to prove this theory on my 1985 f-150 .Ran well for months until high humidity . I experienced backfiring ,crappy performance ( fuel mileage stayed same) Good luck TR