Can I disconnect smog pump?

[MariaAZ]

The idler pulley on my 260Z looks like it's ready to break; the bolt is backed out quite a bit and the pulley part is bending visibly. When the motor is running, there is an awful rattling from the front that looks like it's caused by the pulley. It is the only running car we currently have, so I really need to resolve this issue ASAP.

If I remove the belt from the A/C and air pump, will it affect the running of the Z? I have retrofitted the flat tops with round tops so the emissions aren't exactly stock

In its current configuration (with the air pump currently connected) the car passes inspection, so I'm also concerned that altering anything might affect this.

[sblake01]

Have you tried tightening the bolt? It might just be that the loose bolt is allowing the pulley to move back and forth on the bolt which is really a combination bolt/shaft.

[doradox]

Yes, you can remove the belt and it will not effect anything adversely. Except emissions of course.

Steve

[MariaAZ]

I tightened the bolt but it didn't do anything to the pulley, which is wiggling on the spindle.

If I ultimately remove the air pump completely, how do I deal with the hose that goes to the engine? It's an early '74.

[sblake01]

Someone else will have to answer the question about smog pump. The bearing, which can be replaced, is the problem with your idler pulley. I've redone a few of those in the past. The bearing is available at most auto parts stores but they come in different sizes so be sure to match yours up as far as outer diameter and center bore diameter. Disassemble the pulley assembly, remove the snap ring, press the bearing out, press the new one in, replace the snap ring, reassemble the pulley assembly, re install it, adjust the belt tension and you're done.

[jtl260z]

I tightened the bolt but it didn't do anything to the pulley, which is wiggling on the spindle.

If I ultimately remove the air pump completely, how do I deal with the hose that goes to the engine? It's an early '74.

I removed mine several years ago. Problem is, I don't remomber how it was originally hooked up. If you could get me a picture of the hose location or describe it I can probably help you out.

[MariaAZ]

I've posted a couple photos below, the first one shows the loose idler pulley, the second shows where the hose from the air pump goes to.

I'm sure this is going to be a dumb question... how the heck do I get the A/C belt off?!?! I can't find anything really useful in my Haynes manual (except how to tighten the A/C belt) Having never dealt with repairing this particular part of the car before (I've swapped starters & alternators, rebuilt and installed carbs but never tried removing the belt from the compressor) I'm about ready to take a sharp knife to the darned thing, as I have about six hours to get this taken care of before I absolutely need the car. It doesn't look as cut-and-dry as removing the alternator belt.

[MariaAZ]

Just as followup... I couldn't access the pulley spindle nut without removing the fan shroud and didn't want to risk not having the car ready by this evening, so I ended up cutting the belt off. The pulley itself is frozen where it is; too much play for the belt to turn properly, but too tight to ease it off. A short test-drive later and I'm surprised at how quiet the Z runs now. I have a feeling this issue has been building up for quite a while.

I'm hoping to re-install the A/C someday (it's factory air but hasn't worked since before I got the car) but until then I'll just leave everything the way it is now.

Thanks to everyone for the help!

Edited September 3, 2008 by MariaAZ

[sblake01]

If you had loosened the long bolt that is behind the pulley, it would have loosened the tension on the belt. At that point, you could have removed the belt from the idler and carfeully fed it over the fan and removed it without removing the shroud or cutting the belt. I've done it several times on that type of setup. I guess it's too late now.

[MariaAZ]

I backed the screw out almost all the way and the pulley never even budged. The block where the pulley is attached stayed put in the bracket, like it's frozen in place.

[sblake01]

You have to loosen the nut on the front of the pulley first. (and tighten is once the belt tension is set)

[bobc]

Maria,

I'm going to offer a slightly different opinion on this one than others have already said to your post. Yes, you can take off the belt from a smog pump, but I wouldn't leave it off for a long time. The pump makes positive pressure in the system, if it's not turning then the exhaust gases go the other way. Eventually, the check valve will corrode and start leaking exhaust gases into the pump. Then the pump will build up with exhaust gases and moisture and eventually the pump will freeze up. With time, the idle will roughen up and the engine will not be as smooth. You can remedy this by removing the check valve and sealing this opening (usually with a nut).

I've seen dozens of Z's with frozen air pumps due to removal of the belts, so short term, you can get away with it, but in the long term, I suggest you either replace it or go all the way and remove the system (assuming you don't have to have it in place and working to pass inpection)

Best,

Bob