Incendier

Let's say, for instance (not that I'd do this), a guy lives in a state without emissions testing, and his air pump is getting noisy, and he'd like to eliminate a little parasitic drag in the process

Is the Euro idler pulley required or can a very short belt be run between the crank and the fan?

If so, anyone know the size? I recall a very early post mentioning a 21" belt with a 4L cross section.

Thanks,

James.

Randy V

Just cut off the belt that powers that air pump James - no further action required - unless the airpump is on the same belt circuit as your A/C compressor - you didn't mention the model year of your car, so this solution applies to older models like mine.

The alternative is to gut the air pump, allowing the continued use of its pulley.

Incendier

Randy - thanks...

My MY is in my signature; guess you get this by e-mail. It's an '83.

My belt is a three-pointer - crank pulley to fan pulley to air pump.

Do I have a mutant shark or what?

Randy V

Ah yes - it is indeed in your tag line - sorry about that.

Randy V

Well, yes and no Snowy. The air pump injects air into the exhaust before the cat to increase its efficiency. If the engine is properly tuned and all, the smog pump function should not make that much of a difference to the emission values. It's when the timing is off, spark plugs are old, running rich, etc. (basically, the condition of many neglected vehicles) that the smog pump picks up the slack.

John Struthers

Snow,
I can't remember wether it was Kaz, Wally, or
, Jim Morehouse who posted on my O2 sensor questions back in September. Our esteemed mediator Randy said the archives were back up but I couldn't find the posts under archive or search query's.
The response, as recollected, was that with a 'bad' O2 sensor the bogus, intermittent, or, non existant signal would put the injector brain into a closed/continuous loop mode which affects mix and idle amongst many other things. Apparently, not for the good.
Something else odd about the sensor. When I tracked the puppy down and traced it there was a big green wire with a following brown
'sister' wire. Someone else posted that I was correct and that they thought it was a ground wire for the sensor. However, unless I'm WAY off here doesn't the sensor ground to the exhaust? And if so what the hell was that brown wire for?
Oh, yeah! I believe the Nichols site has the part number for a replacement (roller) bracket part number to run the belt if you remove the pump -for storage, no doubt-. And also has several recommendations for the smaller belt if you were going to do it that way.
hth,lol,
Keep em' rolling
John S. & Pattycakes

Incendier

Ah, Snowy, you're spot on. I haven't had to deal with the cat question - I'm "testing" the system.

The extended test I'm running with my test pipe has included plumbing for the 02 sensor.

My dismantling so far reveals: the air pump system goes from the pump down the rail on the passenger's side of the engine, to the diverter valve, which sends air to either (a) the airbox or (b) the exhaust through a large check valve that sits vertically at the back of the engine. It's independent of the air regulator.

John, thanks...thought I had checked the Nichols site, I'll check again.

Randy V

John - after selecting 'search' at the top of the Board, I entered "o2 sensor" (without quotes) into the search field - I get a whole bunch of stuff:

O2 Sensor

About That O2 sensor

Do Engine Sensors Require Ground?

Plus a bunch more. Let me know if you need assistance in using the Search function here.

Steve Cattaneo

steve cattaneo
User
User # 478
User Rated:

posted 08-19-2001 18:50
--------------------------------------------------------------------------------
John
The computer won’t reset because it read a hard code, a total failure of the 02 sensor or wire circuit, it’s running your fuel system in a open loop control mode, no input from the sensor that failed. The 02 sensor is one of the most important input of any car. It controls the air/fuel ratio by means of the fuel injector pulse time.

Less 02 in exhaust = voltage increase = computer reduces fuel = lean mixture.
More 02 in exhaust =voltage decrease=computer increases fuel=rich mixture. Closed loop control. Any electric repair should be soldered .by an air/fuel ratio gauge to make tuning adjustments
stevec

928 Brothers

It uses the same belt as the cooling fan. You have two options. 1. Replace air pump with euro pulley. 2. Use an electric fan and bypass everything. You will NOT have any problems if you remove the air pump. It will also give you some real horsepower .

John Struthers

Steve,
Humble apologies for forgeting so valuable a source. Especially, one posting a specific response.
Thanks for the the original and repeat.
John S. and Pattycakes

John Struthers

Randy,
Quite possibly my bad , but I did try the search mode at top of the page as well as going back to the archives search, Tried 02, O2 sensor,O2 oxygen sensor and plain old oxygen sensor. used no commas or periods only spaces as (I think it was you )directed earlier.
All I got was the negative in dialog form.
I'll try again and If you don't hear from me on the subject then MY problem is resolved. BTW your threads worked fine.
Thanks for the help and I'm glad the archives aren't lost.
Two other things.
1. Do you think the crash was in any way attributable to all the PIC posts?
2. Was that your post on Greg Nichols site about a 1986 where THE BELT shucked some teeth at the crank drive? Zero damage? Back in 1999.
If so, did you go to church on sunday for a while? And could I borrow a squad of Guadian Angels from the platoon that was watching over you?
Thanks for the assist and will do penance for my side ways,(unjustified) slant at the lost archives.
John S. and Pattycakes

Chris Lockhart

My set-up is a bit different, since I have an'89, but my cat bypass from 928 Specialists already had the bung for the O2 sensor. The bypass was a direct EASY bolt in. I have since switched over to the MSDS headers, and the right collector has the O2 sensor bung. I deleted ALL of the sog euqipment. Air pump, lines hoses, valves, etc..., and sealed the lower hole on the right side of the airbox with epoxy. I don't know how much parasitic drog I eliminated, but I'm sure it wasn't much. No reason to keep any of the equipment on it with headers though. Also, I had written down a P/N several years ago in my 928 notebook, for the "short" belt needed when eliminating the airpump from the earlier models. It is a Gates #7417. Now that came from a Rennlist post about 2 years ago, so YMMV.Good luck with the "deletion".

Incendier

Thanks, Chris. Post held on the Nichols site had a different brand and belt number, which utterly baffled the guys at my local parts store. "That's an awful small belt for such a big car...whatcha doin'?" followed shortly by "what's an air pump?"

*sigh*

Randy V

John:

1) It's possible, but doubtful. It's just data, albiet much more.

2) I did have such an occurance, although it was on my '79. I initially feared the worst (broken cam), but it was just some sheared teeth - belt was R&R'd by my mechanic gratis, as I had just had the belt/water pump done a few weeks earlier.