I started another thread, coz the other one is old by now.

As in the previous, I ventured into the depths of the Black Beast to replace the infamous bent hose, only to find it was NEW, as was the other bent hose at the top of the vent pipe, GOOD.

Reusing the intake gaskets was the root cause of the stumble.

Or so I thought.

Started the stumble again, NOT as bad, and MORE intermittent, BUGGA.

Not having any more gaskets I was hesitant to remove that manifold again, but if push came to shove, so be it.

Found the can of "Ether" (Cannot use the name on the labelled as the word is a no -no on public forums). Sprayed it around the manifold joints, NO change, SWEET.

Got down the back and under the plastic manifold, sprayed, NOPE, still good.

Now I was worried, and thoughts of numerous huge $$ items flashed around, so JD needed to calm the old guy down.

Anyway, I noticed the top elbow moved when I was pushing around to get under the lower manifold, which at the time meant little, but now, "this is not supposed to move so freely", so sprayed the stuff on the joint, AHA, gotcha.

Simply fitted a hose clamp, sprayed again, SWEET. No more stumble, YET.

This obviously only applies to the early cars with that silly hose in the "V". I note in the parts catalogue that the later cars have a blanking plate in lieu of the oil seperator, and NO bent hose, so must breath via some other means/plumbing set up. I may look at the possibility of "updating" my 2, so that hose is no longer there??.

The snap is of the Silver car, with the manifold off, as that cars lower hose is toast.

 

Well found

Maybe it's why the later cars have oil pooling and need IMT work?

 

MMmmm, maybe.

I noted that the plastic pipe/hose from that elbow goes direct to one of the vac port on the throttle body.

Both ours have oily film, quite heavy actually, in the inlet manifolds, AND the updated IMT seals, so no pooling on them, and/or vac leaks.

I will look into the different systems over time and make a decision. The upper still requires removal for "A" bank coils/plugs, but at least the plastic lower manifold could stay intact, basically forever.

 

Good work and thanks for sharing your findings and results! I had the dreaded stumble then proceeding into P1074 and P1071 TCs. Kept searching for the vacuum leak and finally found it as my EGR valve. Its not always the infamous hidden intake manifold hose.

 

Good find VMV.

We dont have EGR down here on any cars, so one, maybe more, item/s to not go wrong.

We had them waaaaaay back, and the issues they caused was simply madness.

Did 300+ kms in the Black beast today, and not a stumble in sight. It took about 100kms for the computers to re-learn all the parameters again, then an almighty SIGH/COUGH, and that was it, sweet as I would have expected.

The Silver one will be finished eventually, work beckons once more, and I expect nothing different with it when done.

 

You can force a relearn by disconnecting battery for a while (hard reset).

I think VMV has P10 where P01 should be.

 

Update Jan 8th:

Started running odd on Jan 5th, busy with other Jags, so it went on the "must get to that list".

Stumbled bad, NO, fell over, died later that day.

NO codes, NO CEL, NO NOTHING.

Established the "old way" huge vac leak, but where this time.

NO idea why, but I returned to the clamped hose in the original thread, coz something simply did not look right, as per the parts diagram??. I had been ordering parts for the other car.

Removed that "adaptor hose" from the stand pipe, bugga of a task, and it was split something serious, OOPS.

Looked further into the set up, and, yes, the top elbow is new and the updated style, then I found there is NO PCV valve. What was joining the adaptor and the elbow was a simple plastic hose joiner.

Got a new adaptor hose and PCV, fitted it back and started the mighty engine, sweet.

This engine has not been breathing correctly for a very long time I reckon.

The 3 snaps tell the story.

 

Ouch. Well fixed!

I expect OBD would've shown either P1000 and unable to set monitors or poor fuel trims. With P1000 it sometimes cannot figure how many things work or don't so doesn't know which codes to flag.