Yesterday I drove my 1997 XK8 about 150 miles and she drove perfectly, this morning I started the car and drove about two blocks and she started lurching and stopping, with brief periods of no power (two seconds or so) then power, then lurching again. There was no transmission fluid on the floor of the garage. I just had the transmission fluid changed and the pump and hoses replaced three months ago. No codes come up at all. What could have happened overnight ?

 

I'd suggest you start a new thread (to keep your issue seperate), also update your signature with you MY and people can pipe in from there.

 

whitexk8 I've moved your post to its own thread - others should chime in shortly.

Are you getting any warnings on the dash (Gearbox fault, restricted performance) - anything like that?

Any codes??

 

WhiteXK8, Any chance you could have a clogged fuel filter? I had a vehicle that acted exactly like this, but then I had a car with bad ingition wires do the same thing, which is not applicable with these cars, but the point I want to make is: The more symptom/situation info you can give us the better the experts can help. What speed were you going? What RPMs, was it wide open throttle?

Did you have a chance to pull any codes? Let us know.

 

No codes at all...no warning lights. The car starts, runs and idles perfectly, only when in gear does it do this. It will go for 20 yards "normally" then it starts to lurch, almost stop, then lurch, then normal for a couple more seconds...I was going no more than ten miles an hour and once it started I could barely limp back home. But no limp mode ...I used a code reader to reset everything, but it did not help.

 

I'd check the fuel pressure at the rail.

 

What is the rail ?

 

The fuel rail - it has a Schrader fitting on it. Advance Auto have a free tool loan service - get hold of a fuel pressure gauge and check what fuel pressure you have - should be 35 - 40 psi.

 

I let the car sit for a week. I did nothing to the car at all. I just started her up, and took her for about a mile with no symptoms at all. There is a small spot of red, what looks like transmission fluid under the car on the passenger side about mid-engine. I noticed a fresh gas smell, rather present, and that the car used about 3/4 of a tank of gas to go 150 miles. I keep premium in the car and was getting about 23 mpg before this trip. I just read the codes again and have a p1000 and a p1643 that will not clear ...I swear this car is possessed !

 

p1643 is a CAN communication fault to the transmission control module. Since you don't get errors from any other module, it is likely not a fault on the bus itself.

First thought would be to check the connections and wiring between the ECU and TCM.

 

The red fluid under the car shouldn't be transmission fluid unless someone changed out the factory clear fluid with something other than expected. The fluid likely is power steering fluid or an engine mount. Engine mounts have a purple fluid and can leak.

 

Thanks for that observation. I figured out what the problem was/is. The Cruise control switch sticks and was either stuck in 'ON" or "OFF" position, somehow the switch got stuck in "IN-BETWEEN" position and was making the car do this, once I shot it with WD-40 it behaved normally after clearing the codes with a code reader. Thanks for all the help guys ...

 

Glad you got it sorted out, and Thank you for posting your solution, it helps add to the knowledge of the forum!

 

I will be listing the car in the next week or so for sale. I have had enough of this...