throttle problem :-/

[David Cullen]

i think its a sticking throttle cable but just want to check if it could be anything else... driving down the road and the car wants to go faster, clutch in and revs shoot up, i s*** myself, turn off the car and pull in, start the car up again and its fine, drive down the road and same thing happens but this time i use the brake to slow the car and changing gears the revs shootup again when clutch in..... what ye recon? is it only the cable from the foot pedal to the throttle body? i was looking at the cable a while ago and thinking, you are going to cause me trouble at some stage, didnt get around to changing it though lol guess now may be a good time thanks guys and gals ;-)

 

[David Cullen]

done some ringing around, only available from BMW got scared when i heard that lol also none in Ireland UK or Germany so will have to wait 3 weeks good news is its only like 30 euro but in the mean time i have to sort something with mine as i need the car will try source one from scrap yard or try oil down the cable in my own till the new one gets here.... either that or a shoe string

 

[GazHyde]

3 weeks to get hold of a throttle cable seems a bit crap.

I think you can try squirting some grease down the cable and see if that helps.

 

[zedonist]

Unfortunately Gaz, these cars are over ten years old, so if the parts not in stock they get to give a supplier a headache of asking for the making a one off and all the costs that go with it

 

[David Cullen]

thats the plan Gaz, i am also going to look at another 3 series we have in the yard and see if i can work some magic with its cable, will sort something out to tide me over the three weeks ;-)

 

[David Cullen]

ok so today i took off the cable from the throttle body and gave everything a dose of WD40 also done any joints on the pedal inside the car, no difference, she was still sticking :-/ so went at the 318 in the yard and took out the cable from her, it got dark so will have a look at it tomorrow to see if it fits, update to follow ;-)

 

[David Cullen]

replaced the cable today with another from a 318, not exactly straight fit so had to do one or two things to make it work, main thing is it works but i still have the same problem ahhhhhh so tomorrow i will look at the throttle body, figure its the butterfly valve, will give it all a clean, again, and hopefully that will sort it :-/

 

[David Cullen]

took the throttle housing off and cleaned the butterfly valves and housing with emery paper and let it dry, then used WD40 on any moving parts, still sticking :-/ dont know where to go from here other than to change the throttle body :-/

 

[David Cullen]

bump...
is there anything else i could be missing here folks? when its stuck and i use the brakes to slow the car, when it gets to low revs it comes out of it.... how about the two sensors on the side of the body? would they have any part to play? head = fried... almost

 

[hard top]

Sorry mate, I have been reading this but I have no idea....

 

[David Cullen]

thanks @hard top
i dont want to go and buy another throttle body if i dont need one.... just want to make sure im not missing something ;-/

 

[David Cullen]

i have had the throttle body out again and i am confident that the mechanisms are all working fine and smooth, my cable is good also so does anyone know if the TPS would hold the revs up if it wasnt working? thanks

 

[oldcarman]

Cue T-tony, Lee, Zedonist and anyone else with knowledge to fix this please! JIM

 

[FRANKIE]

i have had the throttle body out again and i am confident that the mechanisms are all working fine and smooth, my cable is good also so does anyone know if the TPS would hold the revs up if it wasnt working? thanks

There is a 'Throttle Body Cleaner' made especially for throttle bodies. Throttle bodies get carboned up after time and they need cleaning. They do have small ports that can get clogged. I think the cleaner CRC and comes in a red can but not sure. Frankie

 

[David Cullen]

thanks Frankie, got a can of that for cleaning and some emery paper for the heavy stuff and WD40 for the moving parts ;-) im not new to all this stuff just new to BMWs thanks man

 

[Lee]

Seeing as you have checked everything mechanically have you tried reading the ECU? I would now start looking toward the idle control valve beginning to stick this would also throw a fault up on the ecu if it’s bad enough. Failing that do these z3's have throttle positon sensors?

Lee

 

[David Cullen]

thanks Lee for the reply ;-) i havent had a chance to read yet, dont have reader, checked last week and all good but i am thinking the TPS myself, and yes there is a TPS on the small butterfly so i will swap that over and go from there, i am not sure that the IACV would hold the revs up, more so thought they would just idle lumpy.... anyway, thanks for the input and hopefully i will sort it by just changing the TPS ;-)

 

[oldcarman]

I'm a fern believer in not throwing new parts on hoping for miracles. Better spent on a prof diagnostic as you've jumped from throttle cable to throttle body to TPS so where will you go when/if that doesn't work and you've paid to replace a working part? JIM

 

[David Cullen]

hahaha good man Jim ;-) its called a process of elimination, i am trying to sort out the problem with the parts i have but in order to do that i must go through all the variables, at the moment i have done the mechanicals and just need info on the electrical, ie. do any of the sensors effect the revs and the sensors involved are the TPS IACV and MAF. i dont know if they can cause what is happening, thats where i am at for the past two days, cant seem to get the info :-/

 

[oldcarman]

@David Cullen, over my 50+ years of dealing with these sort of thing the process of elimination usually eliminates a lot of cash from one's wallet and very seldom solves the problem. Time to get out the manual and read it front to back and find someone to answer your questions with knowledge not guess work. I commend you for persevering but get a proper diagnosis, it will save you $$$ in the end. JIM