G'day Gents:

I'm still having problems with the lean condition. Bank 1 short term will read between 0-8, and bank 2 between 0-4. Long term are correspondingly high at ~14 and ~18 respectively. When you run through a range of rpm bank 1 is consistently higher.

There are a couple of vacuum leaks remaining.

First, there is an "elbow" under the throttle body. It's a separate piece and there is a vacuum line that attaches to it. It's a "chinese handcuff" kind if connection where the tube pushes in and snaps into place. When we smoke test it from the top of the TB this connection leaks. Holding the tube tightly in place while reading the meter didn't seem to change the readings. A couple of questions:
1) is this a critical area for a vacuum leak?
2) is this "elbow" available as a seperate part without the entire TB assembly?

Second, there is a wisp of a leak remaining at the intake manifold. This is located at the forward most bolt hole at the driver's front side of the engine. (this is bank 1 right?) We epoxied the hairline crack that was there which greatly reduced the leak but a very minor leak remains there.

I swapped out the MAF with a known good one from my wifes XJ8 and eliminated this as the culprit.

I supppose I need to fix these 2 leaks but I hesitate to go for a new intake and/or TB.

If anyone knows of the "elbow" I describe and if it's available separately I'd appreciate the info. Also, what are your thoughts on the intake manifold? Should I bite the bullet and repalce this too?

Anything simple I might be missing here?

Thanks!

Tom

 

Tom,
You need to tell us the model and year of the car you are working on. You do not have it listed and you posted in the XK8 area when you listed a XJ in your comments and your profile says XJ.

 

Gus, it's a 2000 XK8 4.0 non supercharged I updated my profile. The XJ was my wifes 99 XJ8 that I swapped the MAF from to check it. Thanks! Tom

 

I am unable to identify the part on the TB that you are talking about. As for the MAFS it appears to be interchangeable with a 2000 so I think you are ok with that. If you have vacuum leaks I would suggest repairing them first before looking elsewhere.

 

Thanks Gus, I was able to determine the part #, it is AJ 81367, the "induction elbow." There is a vacuum tube that pushes into the right hand (passenger) side of the elbow. When we smoke it smoke leaks out here but I'm thinking normally, under vacuum conditions, the seal would be made tighter (rather than loosen under the positive pressure of a smoke test). So we are going to do a propane test to see if it is leaking. Still, I'm thinking if this leak is the culprit, it would give balanced readings on both banks. My bank 1 is consitently giving higher lean readings. Any thoughts on why bank 1 would be consistently higher? Thanks, Tom

 

Guys,

An update...I replaced the induction manifold and "elbow." All fuel trims came down and it looks like I've got that problem licked.

Have also replaced the LH cam cover and gaskets and have carefully checked it, but am still getting whiffs of oil and a little smoke indicating an oil leak. This is at the left rear corner of the left side cam cover. Can't seem to locate the problem though.

Any suggestions? Is this a common problem?

Thanks,

Tom

2000 XJ8

 

My car was leaking at the same spot when I bought it. A new cam cover gasket fixed it but I still had a burned oil smell. It finally went away after burning off the old oil trapped by the exhaust manifold metal gasket. It makes a 90 degree bend outwards and can trap oil, so maybe your leak is fixed and the old oil residue has to be cleaned or burned off.