Hi, sean,

I injected the smoke at the vacuum line that goes to the brakes.

I didn't test the air intake (mine is an NA, so only one air intake). Rather, I blocked off the throttle body with a 3 in plumbing cap from Home Depot, because just trying to put a glove, for example, over it didn't seal it tight enough when I want to increase the injected smoke pressure.

I found to get all the little areas of leakage I needed to put a fair amount of pressure inside the vacuum envelope. I found minor leaks in several places, usually due to old O-rings in various places. The oil fill and dipstick both leaked. My single biggest vacuum leak was a seriously damaged injector lower o-ring. When pressure got high enough, smoke began blowing out around the injector pretty quickly. Note I have a 4.2, meaning port injection.

Currently my ltft is around minus 2% on both Banks, which leads me to think that I got all of the vacuum leaks. I might go back in at some point and seal off both ends of the air intake to smoke test it. It never struck me that the design of Jaguar air intakes seemed airtight. The engine idles plus or minus 5 RPM, which again leads me to think that the mixture is good. The idle MAF is stable at about five to six grams per second, also in spec.

I hope all this helps. Reach out again if I can be of more assistance.

Best, panthera.

ps: the crankcase is part of the vacuum envelope. I had no leaks there. One of the thing I found was that it helps to turn down the lights in the garage and poke around with a flashlight so you can catch the small amounts of smoke coming out.

 

Much appreciated. I don't recall my LTFT's but think one was off more than I liked. No codes thrown. Car is in storage but I thought I'd at least eliminate vacuum leaks.

 

What I found out about ltft after researching it for quite a while is that vacuum leaks will usually result in a positive ltft on each Bank. Ideal of course is zero percent. Anything over 0% means the ECU is increasing injector time to add fuel due to calculating extra air in the vacuum envelope. +15 to 20% is likely to trigger a code, and anything less than 5% is just fine. I'm sure you know all this, so I'm just noting it for other folks who may read this thread. Cheers.

 

Well shoot. No positive battery terminal in the engine bay. My smoke machine is 12 volt.

 

The positive lead won't reach the lug behind the L/R wheel?

 

No it's only about 4 feet long. The end that connects to the machine is shaped like the old power cords for Desktop computers. I might have one of those laying around that I could try. If that doesn't work, I think I'll just pull the battery and place it behind me on the bench and run it that way. I'll keep a charge on too. Just me whining.

 

Make yourself an extension cord to reach wherever you need.

 

Thanks for the suggestion @kj07xk . I had an aha or duh moment and just pulled my wife's car next to mine and used her battery. No vacuum leaks.

 

Agreed and thank you again. To close this out, the roads are finally free of salt so I connected the battery and went for a spin. LTFT were normal. I'm not sure what I thought I saw last fall.

Bank 1 - Highest value 3.9, lowest value 0.0 and 3.12 @ idle.
Bank 2 - Highest value 3.9, lowest value 1.6 and 0.0 @ idle.

I know that's not what this thread is for but since I stepped in it, I thought I'd close it out. Nothing to see here and damn is it nice to be driving her again.