I believe this is the cause for my car running rough at idle and after 5 pounds of boost.

When I searched online for the routing of this vacuum line, I couldn’t find another XJR with this black canister thing. So maybe it’s specific to my MY?
98 XJR

 

Black canister is for cruise control on any Aj26 engine.

 

Ive never seen that on a x308 before. i does look to me like a cruise control part.

 

ALL AJ26 throttles I have seen have the vacuum actuator.

 

Do you have a diagram showing where the other end is suppose to go?

I’ve looked all over the engine bay and can’t seem to find a spot for it

 

Evap Valve ?

See page 65 , 70 , and 73 . I do not have this engine

T881 TITLE

 

I'm more concerned that your coolant overflow lines look to be on backwards. They should criss-cross so the line nearest the side of the car goes towards the center and line coming from the center goes to the outside. This photo looks like they're backwards from this angle.

 

I think the vacuum hose from the canister should be going to the cruise control vacuum actuators. Three of them. I xk8 they are close to the ecm. But I don't know about the xj

 

I believe I’ve narrowed it down to these two areas.

This is by the air intake front passenger side. But I know this has been broken long before I got the car and it drove perfect up until recently.


This is by the brake booster.
this I believe is the real problem since it’s a vacuum line coming from the throttle body.



Would either of the cause rough idle and misfiring after 4-5lbs of boost? Runs perfect in park.
The one time I did use cruise control it threw my car into limp mode, but this was when I got the car over 2 years ago.

 

It may not be OEM status but i believe I have it setup right, I just had to modify one of the lines.

 

Coolant lines look correct. I think the other end of the cruise control goes to the fitting on your second picture.

 

just attempted to run the car with that vacuum line held on by a friend and just threw my car into fail safe mode. Followed by 2 codes
P0306 - Misfire Cylinder B2 (6)
P1316 - Injector driver module codes detected

 

Clear the OBD codes; hard battery reset; try the nib in picture three . . . sorry nobody with a AJ26/SC motor is answering . . .

 

I ended up buying some T fittings from autozone and put them in both of the spots that broke off.

That took away the FailSafe Engine and cleared up some of the hesitation but it is still definitely there after 5 pounds of boost and at idle, just not as bad as before.

Could this be fuel related?
I noticed the injector wiring getting stripped from rubbing on the charge air coolers so I rewrapped them but one of them WAS SHOWING wire

 

So after driving on it for a while, I’ve noticed that it only starts to really misfire at idle when it gets to operating temperature.