Well after about two years, the XJS is running (sort Of). Starts right up, but was idling hi, about 1225, did manage to get it down to about 800 to 850, somewhere in there as I checked the rev counter from outside the car. Got it down that far by disconnecting the vacuum line at the ECU. And that's after trying to adjust the ECU with getting no change in idle. After tearing down the top of the motor/engine, going thru all the wiring, changing fuel line and vacuum lines, and cleaning connectors and contacts on things, along with some new parts, I can stand outside the Jag and starts right up. there seems to be no misses or hesitation when revving it up, no back firing either. All sounds good right? Now my right side CAT gets cherry Red!! Something else to chase around and figure out Oh, as far as the idle, it may be because of the large bore throttle bodies, and I haven't bought an enhanced ECU yet to match up. Guess I will see about repositioning the Dizzy a bit and see if that helps.

 

Well done.

Larger throttle bodies require the disc clearance to be at 0.001" instead of the 0.002" with the standard discs.

I doubt the ECU will "see" this change, other than you will have a "bigger" vac leak as far as the ECU is concerned with the large discs set at 0.002".

Lucas car with glowing Cat, not common unless the loom is shorting??..

 

Thanks for the tip on the clearance, will recheck that, I believe I may have set them ad .002. As far as the wiring, I have gone all thru that.

 

Has the beast got cold start injectors?????

If so remove them from the fuel supply AND the electrickery. They dribble fuel.

Next would be the FPR units.

I assume it still has the 2 units???.

Remove the small hoses from each and note if raw fuel is present. They rupture and raw fuel gets into the system, and is unburnt, and Cats glow.

The RH FPR can be deleted.

 

If your cat is going cherry red, I believe that indicates severe overfuelling and that petrol is burning inside the cat. Stuck injector? Earthing injector loom?


In general, over-revving at idle is often a symptom of a stuck open AAV. Have you tried adjusting he idle screw on it?
Greg

 

+1 on stuck injector or grounding injector wires. You should be able use a mechanics stethoscope to listen to each injector.

 

Fuel injectors rebuilt and tested, injector wire loom re built, but thought of going thru it just in case. All fuel lines are new, and fuel system was blown out before putting new gas in the tank. fuel pump, filter and sump filter are all new. Does not have cold start injectors, AAV is new. But, like said earlier, am going o re check the injector loom(maybe I did something wrong or did not get a connection right) and dido on checking the injectors anyhow, just because I had them done and checked does not mean one or 2 could be sticking. Oh, and all plugs, wires, dizzy cap and coil are new . now that I have some ideas from you all, I have a better starting point.

Been years since I studied automotive tech at school, and have worked on a couple of Jages and a couple of other British cars then, but of technology has advance since the carberator days, but still feel confident enough to solve things

 

Pull all the plugs on the A bank this should tell you a lot about how this side is running.

 

Keep going on too rich and the cat will be toast!!! Don't ask....


Carl

 

problem should be solve, 3 connectors on the "A" bank were not making contact, when I rebuilt the harness I even check, checked and checked some more to make sure things were alright with it. Gremlins must be in the garage again, time to spray the Gremlin replant LOL

 

Well done.

Gremlin spray is the only way.

 

well, took some time off from the Cat, decided to get back on it since I have not done anything for around 2 weeks, was having some problems with my physical disabilities, but the rest did me good. So I said to myself "Self time to get back in there and conquer that B*&ch" Got the dizzy set in, as before the XJS started right up, runs smooth even when revved up there is no hesitation or backfire, no pings. but have not had it out on the road yet as need to have some other parts to put back on. RPMs according to the Rev counter/Tach is about 800 at idle (I Know it should be 750, but looked at it from outside the car) and no engine shake.

Only problem is the CATs are still getting hot, but have notice kind of/or a black sooty type of stuff that on the the garage floor, no a lot, and the inside of the tail pipes are blacken with the same stuff. this is leading me to think that either the CATs are bad, or one of the boxes after the CATs are blocked or restricting exhaust flow. will have to try to remember to post a pic of the sooty stuff I mention and possibly the inside of the exhaust tips. I have seen this before back in the day, and beside the before mentioned, I just may have some back pressure going on. When I first got the XJS 4 injectors were completely blocked, and 2 others looked as they were partly block.

Guess I am getting a bit winded hereon this one. So there is a good and bad to this:

Bad: may have to replace the boxes.

Good:
I did plan on replacing the exhaust with a 2 1/4 inch exhaust in the future but may have to do it now. since it is coming into the could winter months, gives me something to do.

Since I will be doing that, I will eliminate the CATs (we have no exhaust test in my state) But then there is no state inspections either. (in some ways no inspection is bad if you saw the how some cars here in Nebraska are. don't even know how vehicles are allowed on the road) maybe I'll get some pics and give you all a laugh or shock on that, like a car with the trunk duct tapes shut or bumper wired up to hold in place. I myself have my vehicles checked over every year.
(Now I got off subject) Anyhow, if you have any ideas on what is going on, your comments are welcome.

 

Sounds like your car is running really rich... The black stuff you are refering to, powder stuck on exhaust tip? When wiper off sticks to your fingers?

 

It's possible that the BLACK STUFF (carbon from un-burnt fuel) is from the cylinders and was formed before you changed the spark plugs.

I have a bad O2 sensor and when I used my as a daily driver last year she would carbon up, a good long drive on the motor way and she would idle as good as new.

I would get it back on the road and give it a good Italian tune up. This will help clean the combustion chambers.

 

I thought of that since it did sit for 2 years with the work I done, and just remember, I did put some (small amount) of oil into the cylinders to keep from rusting up, that may need burned out also. But yor advice is well taken and will have to do.