hi to all

not been here for a while but i'm back because i still the XK8

XK8 1999
got a problem that i hope the techs, or anyone else, can help with. the problem started acouple of weeksago. started the car and the engine started running erratically (revving up and down). then it ran fine after the first instance. however, over the last few days it has started doing this again and the engine revs erratically every time it is started up and it wont stay on until i put it 'drive' and drive off. the engine seems to settle down after putting it in 'drive' and back into 'neutral'.

any offers or suggestions would be most welcome.
t


***still with the elite, 'cos i got an XK8***

 

Check for any engine codes. Clean the throttle body.

 

thanks for your reply Ken.

i took it over to the mechanic the other day and he checked for error codes, but no error codes could be found. sprayed some carb cleaner into the air intake and it seems to have made a little differance but not sorted the problem totally. ran out of cleaner so going to get some more and see how it goes. will keep posting updates until the problem gets sorted.

tariq

***still with the elite, 'cos i got an XK8***

 

Don't recommend throwing parts at a car, but.... whenI changed the crank positioning sensor in my car (thanks to forum recomendation. Thanks again, guys) it solved a lot of my problems (especially hard starts). A CPS runs around $70.

Note to all: mechanic told me the other day that jag recommends a reflash of the ECM every 2 years to fix "bugs" in the system. Especially in the older models.

 

Don't let the carb cleaner go through the airflow meter. It will take them out in a heartbeat. Just a word to the wise.

 

reflash evey 2 yrs? thats news to me. sometimes more like every couple months. some releases we dont even get cause they find a problem with the sofware before its released... On this problem I would clean the part load breather, throttle body and you need to look at dat stream with a scanner to read the mass air flow reading. I f you want to clean the mafs, use a cleaner secifically for it, not carb cleaner. otherwise most times Ive found this problem from erratic mafs reading to the ecu and its not really sure how much air is going through at idle....

 

thanks to all the guys for the above replies. sorry if i have'nt posted for a few days, but i have been keeping up withthe replies. haven't been able to take it over to the mechanic yet, but intend on going next week. early prognosis from the mechanic is that it could be something to do with the throttle body. his trying to get a spare one to try on my car and see if it solves the problem. i will keep updating the results for the benefit of users of this forum.

in the meantime, i've had another problem creep up, seems like the water pump. going to have a go at doing it myself. i'm no expert but can do most work myself. looking for any tips or guides on changing the water pump/thermostat/drivebelt/idler pulley. by the way, i'll start a new thread on this subject, so please dont reply to the water pump issue here. the new thread will benefit users of this forum that are specifically looking for water pump threads.

again, many thanks for all the replies

tariq

***still wit the elite 'cos i got an XK8***

 

some early results.

cleaned the throttlebody intake (around the butterfly), and also the intake pipe from the MAF sensor and the breather pipe from the right side rocker cover. there appears to be a marked improvement, with the engine now idling smoothly. didnt buy any parts yet, will see it runs over thye next few days. will post results again for the benefit of other users.

T

***still with the elite 'cos i still got the XK8***