I had the same problem but with only a local drive. Cat started fine, drove fine to the gas station. Turned off cat, went into store (6 minutes), returned to start cat, engine started, then immediately stalled. I had to wait an hour, then it started and got me home (while my foot was constantly on the accelerator even at the stops).

I followed the Throttle Body cleaning with the toothbrush trick, reconnected intake hose, started up, revved up, took foot off the accelerator and the deceleration went slowly back to idle without a stall. I did this several times.

Prior to that, a week ago, I had some nasty P1396 code for the oil/VVT, so I did the Brutal method of higher oil viscosity, but no 50w, could only find Castrol 10W40 (on sale). I cleared the codes along with cleaning the throttle body, so we'll see what happens. I'm going to do a few local test drives during the week.

THANKS BRUTAL!!!

 

I had the same problem, my car would shut down after extended driving on the interstate.
I would do 100 mph and the car would shut down, i would slow down and i could start car again and continue on my journey.... It turned out to be a bad alternator, on the interstate the cars rpm would be high and the alternator was bad and pushing out too much voltage
the the car would shut down. I changed the alternator and the problem went away...

 

Wow, I'm surprised at all the reasons for the stalling...and the various fixes. I just wanted to report back about the P1396 code for the oil/VVT that was kicked off when the car started to stall. After I cleaned the throttle body intake (in and around the butterfly), I reset the check engine light and the code hasn't come back in two days of driving.

There is still some harder build-up just inside the throttle body intake right around the location where the butterfly is (when it's closed), so I'm going to take a chisel to that (just kidding) - I heard there is a "special" coating on the inside of the throttle body, so I'm just going to get a harder plastic bristle toothbrush or something like that.

I know that oil is supposed to be part of the intake coming from the air cleaner and the breather hoses, but I guess that creates its own problems in the throttle body after the gunk builds up. Cleaning the jag I guess is like watching a real cat constantly cleaning itself.

Oh well, it's back to running fine and I'm happy. Until next time!

 

I had a terrible problem with my car stalling unpredictably at highway speeds.
I read about someone cleaning the throttle and air intake housing with a toothbrush. I liberally sprayed mine with CRC Throttle Body & Air Intake Cleaner from Autozone, and used a toothbrush to remove a bunch of gunk that must have been causing the throttle to stick when the engine is hot. This solved my potentially life threatening problem very cheaply, so I hope it helps anyone else out there experiencing terrifying stalls at high speed.

 

Since this has popped up again, does anyone have a picture of where this
idle air passage is located on the TB?

 

Hey Plums, I cant find any diagram that identifies it for sure, but..... the purpose of the passage keeps air flowing when the blade is "closed", although it is never really totally closed. With that being said my process of elimination deducts its that hole on the LHD drivers side directly superior to the blade. Correct me if i'm wrong though!

 

The blade IS TOTALLY CLOSED at times. That is why the recall 303-S514am Operation Of Throttle was issued. The throttle is commanded CLOSED by the ECM at times to 'wipe' the bore. (keep it free of deposits)

The problem was the engine vacuum KEPT the throttle plate closed and stalled the engine.

Reprogramming the ECM or replacing the throttle was a solution for this fault.

At rest, the throttle blade is partly open for enough air to start the engine.
The ECM/throttle motor has the ultimate 'say' in the throttle angle. Your pedal position is merely a request.

bob

 

Good to know thanks, so where would the iac passage be then?

 

To follow up I took a look down mine and that is the only passage into the TB (pic I posted above)

 

I had the same intermittent stalling on my 2002 XJ8. Then car would not re start despite 6-8 times, then finally re start smooth and drive properly.
Car has only 37k original miles.
my mechanic replaced the fuel pump relay & it solved the problem.