Smog pump delete, and a PCV question

[bennylava]

I would like to take the Smog pump off my 1987 Silverado TBI 350. I'll just take the belt off the pump to begin with, just as a trial run before I remove the pump itself. But there must be a catch... surely that pump not running anymore has some kind of effect? Something that has to be dealt with?

Its pumping straight air into the motor so... now there will be less air going into the engine? Something about that sounds like a bad thing.

Next question, is there more than one PCV valve for me to change out? Or only one on the TBI 350's?

[geezer#99]

THere's only one pcv and the smog pump doesn't pump air into the motor, it pumps air into the exhaust manifolds. The air mixes with the outgoing exhaust. Lowers emissions.

[bennylava]

Ok so will the exhaust smell worse? Just curious about that one, don't really care much. I just like to know everything I can before I dive off into something.

[geezer#99]

It might!
What do you hope to gain by removing it?

[bennylava]

Hmm, good question. I have a friend that has had 2 350 tbi engines over the years, and he said they always seemed to run better without the smog pump turning. Which does make sense at least. 1 less drain on the engine's power.

[geezer#99]

I read a test one time about hp loss from various parts on motors.
IIRC the air pump took about 5 hp to run at 5000 rpm.
In your case likely less than no hp loss at any rpm you run while cruising around.

[Dead Parrot]

Before pulling any smog stuff, double check your state inspection laws, if any, and verify your vehicle isn't subject to smog checks. It would suck to spend time, money and skinned knuckles removing stuff only to have some inspector tell you your truck fails and you have to find and reinstall new stuff.

Keep in mind that pulling the pump means you have to either remove the eight rusted injector pipes from the manifolds or crimp them off.

If new exhaust manifolds or headers are possible future thoughts, might wait until then to pull the pump.

[abig84]

should only have one pcv valve on the valve cover if your 87 is like my 90. make sure its pulling vacuum, my passage under the tbi got all clogged and blew out the intake gasket.

also my 1990 doesnt have a smog pump, dont think it even came with them but i always took them off of all the previous older trucks or they were already broken and disconnected when got them

[bennylava]

For now I was just going to remove the belt so the pump didn't turn. When the ol 350 finally gives up the ghost, I was just going to swap in an LS motor for the fuel mileage and hp/tq gains. So those exhaust manifolds will just be staying on this old motor forever.