Ok, I'm going through my parts car 1985 S3 XJ6 to get it to run nicely before it goes into storage, to be used for parts on a mk2 at a later stage.


Its been sitting for a long time, never running, I have since gotten it running again, albeit terribly.


What I would like to know is the thread size for the air injection ports on the head for each cylinder, the pump and everything else has already been removed as it was seized and all vacuum lines perished/brittle/cracked.


I plan on plugging each hole individually.


Once that is done then I will start on replacing every vacuum line on the motor, as it struggles to idle and I know that at least a few need changing, is there a vacuum hose diagram available?


I'll keep searching, as i'm sure this has been covered numerous times before

 

SIII Vacuum Decals its a start

 

Nail Anchors I'm sure there's a less permanent destructive option than this, hammering in a nail? really?

 

Spent the arvo cleaning the throttle body, intake piping etc
Noticed the AFM door is bent, I'm going to assume because it also runs on gas, this is due to backfires, I cleaned the AFM, polished the internals with autosol and the door operates smoothly now compared to previously, a new one though is required.

Tidied up a few vacuum lines, replaced a split one, bypassed throttle body coolant hoses, and all i've seem to have acomplished is to make it run even worse once I reassembled everything.

If anyone knows the plug size for the EGR on both manifolds as well, that'll be appreciated.

I'm deleting everything that's old and suspect, that could possibly cause an issue.

 

I believe the diagram that is in andthatsjazz.org dealing with the delanair mkii HVAC system (towards the bottom of the page) has everything vacuum related. Good luck!

 

Question: won't deleting the air injection tell the FI ECU that the engine is running too rich (O2 sensor reading)?

 

Nope.

The air injection serves its purpose only on cold engines before the oxy sensor is part of the picture.

After the coolant reaches xxx-temperature (157ºF I think) the air injection diverter valve opens and the air is 'diverted' away from the exhaust ports and, harmlessly, into the air filter canister. This is during the warm-up phase before the system is in closed-loop operation, and therefore is running on a 'fueling map' where oxygen sensor input is disregarded.


Cheers
DD

 

Doug, I hope the we'll have the technology to backup your brain one day. Don't worry, just the Jaguar part.

Thank you once again.

 

Possibly a little bit of help here.... https://www.jaguarforums.com/forum/x...icolour-97221/

 

To plug the openings in the manifold where the air rail was, take it down to the local hardware store.


Peruse the plugs in the plumbing section as well as nuts and bolts. In that manner ID the thread type. then many to choose from.


The Ram Horn manifolds that came with my LT1 were new. It's holes dfopr the air rails were plan old NPT and had plugs in them.


Alas, I needed air rails to pass CA special SMOG. My son gave me and old set and I welded, cut and drilled them til they not only fit but "looked right".


My car has an electric air pump. works for about three minutes on start up, then goes back to sleep. Little parasitic drain.


Carl

 

Well I removed the air injection manifold this arvo and it appears that the thread into the head is 1/8th npt.
I've also removed the egr setup, and it appears someone beat me to it, the pipe that enters the rear of the inlet manifold has been crushed closed at the end of it.

I will make up a block off plate for that and take the egr valve and air injection plugs to a bolt/fastener shop to get suitable plugs.

Looking (or feeling) into the inlet manifold from the egr opening reveals a LOT of oil and carbon residue.
Will leave as it is for now, but will be running some Subaru upper engine cleaner, similar to Seafoam in the states to clean some of it up.

 

Fitted some 1/8th npt plugs and removed the air injection setup completely, much neater now, and you can barely notice the plugs in the head.

Making up an EGR block off plate this week too, but tossing up whether or not I should just remove the inlet manifold, doing that will allow me to assess the condition of everything there properly, and then I'd strip and clean the Idle Control Valve, replace all vacuum hoses, seal all threads that could cause air leaks, clean all carbon/oil residue up, replace gaskets and so on.

Basically eliminate any faults I may have overseen.

Also removed the Air Con system, will never be used, compressor felt really tight (almost seized) and it had no gas in it, much tidier engine bay now compared to when I started, this will just help me in the future when its time to strip the driveline and wreck the rusted out S3 XJ6

 

This post has definitely progressed from just simple air injection removal.


I figured i'll keep tabs of my progress here now.


Recently I haven't had much luck getting it to run right let alone idle.


So seeing as I want to have this driveline in working condition for future projects I got stuck back into it again this weekend and again this arvo.


With fresh fuel in it again and confirmation the fuel return is going back to the same fuel tank, RHS tank is rusted out (now completely disconnected) it fired up and idled with minor throttle held open. Would idle much better with the coolant temp sensor disconnected otherwise it would just stall.


Could rev it a bit until I gradually started getting worse and worse and running on what felt like 4 cylinders.


Plugs are new and leads test fine on multimeter, so i'm suspecting clogged injectors, most likely due to rusted tank, old seized fuel pump, dirty fuel filter and running on gas only for the last few years of its registered life.


So today I stripped the fuel rail and injectors and idle control valve setup, then decided to just completely remove the inlet manifold to refresh everything.


I'll replace fuel hoses as they're rock hard, clean the injectors, new vacuum hoses, clean all idle components, reset throttle body clearance, new gaskets and fresh coolant and oil/filter along with another fuel filter and a blow out of the fuel lines again just to be sure.


Wont cost much, will just be a bit of labour.


Before I stripped it I did a dry compression test
front to rear were 155, 155, 150, 155, 130, 160
did a wet test afterwards and the results didn't change, so the discrepancies are most likely valves not seating rather than worn rings.

 

[QUOTE=Stoney85;1167507]Fitted some 1/8th npt plugs and removed the air injection setup completely, much neater now, and you can barely notice the plugs in the head.

Making good progress.

I've got the 1/8th npt plugs ready to go in when I remove the remains of my air injection system. Did you use any sealant around the plugs or was that not necessary?

Thanks.

 

Most 1/8th NPT plugs are a tapered thread, so the more you screw them in the tighter the fit.


However some thread locker/sealant can be used as well, probably worthwhile seeing as its a right into the combustion chamber where a lot of heat is developed.

 

FYI: the ports on the head for the air injection system are not NPT (national pipe thread) they are BPT (British Pipe Thread). They are not avail at your local hardware store you will have to purchase online at a place like where I did at McMaster. The 1/8" NPT are very close but you will only get a couple turns, as the pitch is different. I didn't even know British Pipe Thread existed until I purchased a kit from a guy off eBay specificly for blocking off the ports and it didn't screw in quite right.

 

Production tolerance might allow an NPT male plug to fit into a female BPT thread.


And, any sealant must be HT. And if the car has an O2 sensor, it must be one that will not cloud the sensor.


Or, tap the holes to NPT!!


Or in a past critter, not a Jaguar, I used the fittings from the rail. I cut off the tubing. Then tapped the hole to a convenient size and used little Allen bolts there. Voila, two piece plugs. Good enough to get by the SMOG guy!!!


Carl


Carl

 

I guess that makes sense seeing it is a British car, I had a 1/8th npt tap and it went in by hand without an issue, so I just went with those plugs.

 

Update to my previous note: It is British Standard Thread (BST), and specifically for the taper fitting it is British Standard Pipe Taper (BSPT). Another Forum member found the item on McMaster, item # 4860K131 for $1.89 each.

I did mine about 10 years ago.

I tried to edit my previous response but the edit button was gone, weird.

 

Yes, you would be able to tap it with a 1/8" npt just make sure to put some grease on the tap so you don't get any metal chips into the engine.