2000 XJR Misfire/Hesitation

[Elwood]

On brisk acceleration the engine hesitates at around 2500 rpm, but revs freely above 3000rpm after kickdown.
Bit dodgy when you go for an overtake, I've used a basic scanner and shows no fault codes.
It seems to rev ok under very gentle acceleration, any ideas would be greatly
appreciated.

[Jaguar steve]

A few things you could check.

Plugs? The XJR should have new ones every 30k and not the 70k of the n/a V8
Airflow meter? Remove it and check the wire that senses flow rate is clean - know anbody with another XJR to try substution?.
Throttle body? Clean out with carb cleaner and a rag.

Now we get to the clutching at straws department

Part throttle breather? Blocked? Clear by hand with a 2.5mm drill bit.
Vacuum leaks? Esp. servo
Blocked fuel or air filter?
Breather system heavily contaminated with engine oil?

All worth a quick look before you get professional help.

[Elwood]

Jaguar steve said:

A few things you could check.

Plugs? The XJR should have new ones every 30k and not the 70k of the n/a V8
Airflow meter? Remove it and check the wire that senses flow rate is clean - know anbody with another XJR to try substution?.
Throttle body? Clean out with carb cleaner and a rag.

Now we get to the clutching at straws department

Part throttle breather? Blocked? Clear by hand with a 2.5mm drill bit.
Vacuum leaks? Esp. servo
Blocked fuel or air filter?
Breather system heavily contaminated with engine oil?

All worth a quick look before you get professional help.

Thanks Steve
Plugs 5k, Fuel & Aif filter new, Cleaned throttle body, will check the airflow meter, breathers and vacuum next, where is the 2.5mm breather?

Regards

[Jaguar steve]

Elwood said:

Jaguar steve said:

A few things you could check.

Plugs? The XJR should have new ones every 30k and not the 70k of the n/a V8
Airflow meter? Remove it and check the wire that senses flow rate is clean - know anbody with another XJR to try substution?.
Throttle body? Clean out with carb cleaner and a rag.

Now we get to the clutching at straws department

Part throttle breather? Blocked? Clear by hand with a 2.5mm drill bit.
Vacuum leaks? Esp. servo
Blocked fuel or air filter?
Breather system heavily contaminated with engine oil?

All worth a quick look before you get professional help.

Thanks Steve
Plugs 5k, Fuel & Aif filter new, Cleaned throttle body, will check the airflow meter, breathers and vacuum next, where is the 2.5mm breather?

Regards

Was the throttle body very dirty or heavily contaminated with oil?

Carb cleaner on the sensor wire of the airflow meter (the bit hanging down from the top inside the bore) and a blast from an airline if you have one should get it clean.

Breather? It's a long shot. On the top of the LH cam cover you'll see a black flexible pipe. There's an identical one on the RH side but it's much bigger.
Depress the ring clip on the LH pipe and take the pipe off the cam cover. Inside the stub there's a 2.5mm hole. Carefully clean it out with a 2.5mm drill bit by hand. Frankly I doubt that's the problem but worth doing so you can rule it out.

[Elwood]

Cleaned the AFM today as suggested, now it it is reluctant to rev at all, any one near Rye have one to try a substitution to prove its faulty or one for sale?
Part# LNE1620BA
DENSO 197408-0020 S/C

[Elwood]

I was cleaning the wrong bit, I dismantled the AFM and looked up the small tube and discovered 2 more wires caked in crud, now running like a dream, happy days.

[Big Rod]

I'll be doing all these this weeekend!

[Big Rod]

Well, I cleaned the throttle body, it didn't look too bad to be honest and the AFM was pretty grotty so gave that a blast. No change, in fact I think it's a little worse.

The seal around the induction tubing and throttle body is pretty well goosed but I think I've sealed it up. I'll need a new one though.

It's really quite rough on idle but fine when driving. Will I get away with driving it like that?

Well, it's going into the garage on Thursday, I'll get them to sort it all out.