I have heard that people bypass the air/smog pump on mustangs to eliminate the power drain? I am only asking because the bearing in mine is worn and it squeaks incessantly. You can hear me coming a mile down the road. I was going to replace it but my buddy told me about getting a smaller belt and just leaving it off. How will this affect emissions/performance/overall? I don't race or otherwise abuse my truck, I just want it to run well and last.

 

Then put a reman pump on it, or just grease those bearings. A few shots of white aerosol grease around the shaft or thru the 2 vent holes in the back should do wonders. It doesn't consume enough power to notice.

 

I think you need a 88.2 inch belt and just undo the 3 bolts that hold the pulley on. That is the easiest way. If you remove the pump you will need to plug the heads or exhaust manifolds, depends on there it pumps to.

 

If the rest of the emmissions equipment is still on the truck and working properly, stopping the flow of fresh air injection will adversely affect the performance most assuredly. The catalytic converter won't heat up and burn off the crud. The O2 sensor will get odd readings due to the lack of fresh air injected into the heads and consequently the computer will try to compensate until something else fails or the O2 sensor fails. Either way, if you ever have to pass an emmissions inspection you will NEVER make it without the pump running. The pumps don't rob that much power and aren't that expensive even if you have to replace them. In short, the by-pass operation is more harmful and costly in the long run.

 

It shouldn't affect the O2 sensor though, because air should only be injected in the heads during cold starts, when the computer is in open loop mode and doesn't take readings from the O2 sensor anyway. The second catalytic converter would not function as designed because of the lack of oxygen, but it shouldn't affect the first cat or the O2 sensor. You could try running without it, and if it doesn't run right, you could change it back. The pumps are rather stiff to turn, although I doubt you will be able to feel a difference.

 

I was just reading this thread, and a question popped into my head: how much air does that air pump actually move? Everything on my mud truck is sans emissions equipment except for the PCV valve, so the air pump has been gone for ages. I was thinking of adding a squirrel cage as a big air mover to get a couple of lbs of boost directly into my carb, but if that air pump moves any considerable amount of air, could it possibly be plumbed to pump air directly into the air cleaner and give any significant amount of boost? Just a miscellaneous question, as it seems you folks know a bit about the air pumps...

 

The air pump wouldn't have enough volumn to feed the engine (intake). All it does is add a little air to help burn any unburnt fuel that passes through the engine.

 

I got a question, how would removing the pump burn the o2 sensor. I had mine removed for over a year and have not had a problem with o2 sensors. And according to a manual I have over the computers, the only time air is pumped into the heads and during long idle to cool the heads. So in that case, running down the road the air go straight to the cats.

 

Thanks for all the info. I ordered a new one for $50. The other was 12 years old anyway.(And I had already tried lubin it up) But thanks for the insight, I haven't had this thing for too long and have very limited time to work on her with the current world situation. Way too many things on the wish list right now.