Replacement of smog air pump on '87 XJ6

Once the '86 XJ6 problem was rectified, it was time to move on to getting the '87 XJ6 to pass as well. The registration renewal dates for these two cars fall within one month of each other. The problem on the '87 car was a bit different. Last time I had the car tested two years ago, it did pass, but barely. Maximum HC emissions allowed at 14 MPH speed is 71 parts per million…the car literally did just that… 71 parts per million. Obviously I was concerned about it not passing this time around. When I took it in to a test station several weeks ago, they would not test it because the belt on the smog pump literally separated. I cut it off completely, and when I did, I thought I detected the sound of a bad bearing when I spun the pulley around. After a series of phone calls and online searches, I found there to be only one company in the US which sells the pump, and ordered one from a regular auto parts store . When I went to pick it up, I found, to my dismay, it wasn’t really ‘new’ but ‘rebuilt’. For reasons I cannot fathom , the rebuilders decided to paint the item in an obnoxious blue color. Why couldn’t they paint it silver gray to give the illusion of a ‘factory original’ part? Oh, well, I had no other choice here. After a few weeks delay, with the part sitting in my trunk with a set of four new belts to be replaced at the same time, my mechanic finally found time to do the replacement for me… I know, many of you would think I should be able to do this myself. Perhaps, but I’m glad I erred on the side of caution. The ‘new’ part requires the use of the pulley part which holds the belt to be used from the old unit. That would be fine, except… the thread pattern on the replacement unit differs from the bolts from the old unit! Fortunately, my mechanic is located a few blocks from a machine shop. He took the new unit over to have them match new bolts to the thread pattern. They couldn’t believe this pump was made for a Jaguar, they thought it was for a GM car. It may well have been… after all, if Jaguar boasted the ‘GM400 transmission’ fitted to the series 3 v12, I suppose anything could be possible. With new bolts in hand, the new pump was installed. He thought the bearing on the old pump ‘didn’t sound too bad’, but I was convinced, especially after reading numerous online articles, that high HC levels are usually caused by a faulty pump. I took the car over to a smog test station a few blocks away… Remember the 71 parts per million of HC reading I got two years ago? With the new pump installed, the figure dropped to only 26 parts per million, a drop in HC levels of nearly two thirds. I’m glad I trusted my instincts… Now my two cars are purring as they should…

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It’s a bit odd, the air injection is only supposed to work during warm-up - when hot; the air is diverted from the exhaust manifold to the air filter. Ie, testing while hot should make no difference to emission levels…

Primarily, the air injection is meant to burn off excessive fuel during the deliberate fat mixture in the exhaust before reaching the converters…

But passed is passed…:):

Frank
xj6 85 Sov Europe (UK/NZ)
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Yup. Passed is passed. But, for the record:

  1. That air pump was found on various critters. For one, my 79 IHC Scout II. Like Jaguar, it used various outsourced parts. Engine, chassis and body by IHC, Most all else sourced elsewhere.

  2. At this late date, new ones no longer in demand. Only rebuilds.

  3. The rebuilder of yours wanted “brand” identity.

  4. Just cause yours was noisy, did not mean it would not pump[ air and make the DMOG guy happy.

  5. Indeed, the first part of a SMOG test is to see that all parts are present and connected.

  6. I have the one from my DOHC in my shed. Why, escapes me. Ain’t worth shipping. If a local needed it, It would be free FOB my house!!!

  7. Does it really matter what color the dumb thing is?

OT; Super Tomahawk is all back together. But, the idler lever does not engage? PO misadjusted or belt too short or too stiff. Look more today? Perhaps. Working on it very Jaguar like. Cramped uncomfortable access.

My mechanic is me!!! As well as house keeper, gardner, book keeper, etc.

Carl

Carl{

‘Passed is passed’ and yes, that’s all that matters…now the two cars will enjoy two more peaceful years…

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One could of course argue that passing emission control tests does not guarantee that the engine runs at its best…:slight_smile:

Frank
xj6 85 Sov Europe (UK/NZ)
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I’ll live with that.