right fellas this is my problem. the car idles at about 2000rpm constantly now. checked the tps voltage and it was fine so i went to adjust the base idle. when i removed the yellow plug the car idled perfectly (about 600rpm) and when i reconnected the yellow plug the idle went back up to 2000rpm. :confused:

 

has the idle valve gone? or is this some other problem? also could i leave the yellow plug off until i get it sorted?

 

cheers

 

alex

bump

 

any ideas guys?

i think , but am not sure the yellow plug is temp sensor ? maybe your car thinks it is on full choke constantly ?? just an idea. come on guru's help Alex out here

 

Steve

Where abouts is the yellow plug you removed?? If it at the front of the engine on the coolant pipes then it is the Temp sensor for the ecu. Could be sending back bad readings.

 

I had probs with this the other week... Took it out and cleaned all of the green cr*p off it and voila!!

twas this one i removed.

http://www.300zx.co.uk/forums/attachment.php?attachmentid=27981

http://www.300zx.co.uk/forums/attachment.php?attachmentid=27982

i was trying to adjust the base idle at the time coz thats what i thought the problem was. might well be on full choke but when i start from cold it does try to idle properly then gradually works up to 2000rpm

Ignore me then matey, thats not the one I was on about. Don't think i have touched that one before!!

twas this one i removed.

http://www.300zx.co.uk/forums/attachment.php?attachmentid=27981

http://www.300zx.co.uk/forums/attachment.php?attachmentid=27982

i was trying to adjust the base idle at the time coz thats what i thought the problem was. might well be on full choke but when i start from cold it does try to idle properly then gradually works up to 2000rpm

 

 

Yes, that is the correct plug on the AAC.

 

Have you checked for vacumn leaks ?

Yes, that is the correct plug on the AAC.

 

Have you checked for vacumn leaks ?

i haven't yet no, but when i disconnect the yellow plug the idle drops right down to 600rpm. surely that wouldn't happen if there was a vacuum leak. i will check anyway just to make sure.

right, i have now checked for vacuum leaks and could not find any. while doing this i noticed the insulation on the yellow plug at the front of the engine was quite badly damaged. had a look at the connectors and noticed they were quite corroded. cleaned them a bit with a knife and there was a slight drop in the rpm.

 

so, could it be the temp sensor causing my problems? and if water has got into the sensor will it be damaged? will be cleaning the contacts later tonight.

 

would really appreciate any comments.

 

cheers

 

alex

Just get those contacts properly clean, that could make a big difference. I've seen two cars recently that permanently read about 71 deg c. This means that the ECU doesn't detect it as a fault, but it does confuse stuff. So your temp sensor could still be partly faulty. Change it if you're in doubt as they're cheap, plus make sure you have a good electrical connection.

Just get those contacts properly clean, that could make a big difference. I've seen two cars recently that permanently read about 71 deg c. This means that the ECU doesn't detect it as a fault, but it does confuse stuff. So your temp sensor could still be partly faulty. Change it if you're in doubt as they're cheap, plus make sure you have a good electrical connection.

cheers andy. will give em a clean tomorrow and see whats what. might change the sensor anyway.

right i have now changed my water temp sensor and cleaned the contacts on the yellow plug as much as i can and annoyingly its made only a small difference.my car now idles at about 1750rpm. really need some help on this now guys. i have no idea what could be causing it to do this. :( oh and i dd an ecu check and came up with a code 55. :confused:

Could be that the idle control valve is sticking. You will need to remove it (4 x 10mm bolts), but they're a bit of a fiddle to get to. Then take the assemble apart and clean it, test the solenoids etc.

Could be that the idle control valve is sticking. You will need to remove it (4 x 10mm bolts), but they're a bit of a fiddle to get to. Then take the assemble apart and clean it, test the solenoids etc.

finally got the bugger off! lots of carbon on the inside so i'll clean that off. how do i test the solenoids? also where can i get a new gasket from? and does anyone know the part number?

There is a tech article on it somewhere, Robbo's site in the US or TwinTurbo .net I think, that will tell you have to test the solenoids too. make suer you get all the electrical connections sure clean while it's off and do the plugs too.

 

MJP will have a new gasket, you might be able to reuse the old one with a bit of gasket goo.

cleaned the idle valve as much as posible, checked solenoids and they're electrically fine. refitted it to my car and still have the same problem so i'll be looking at the air reg tomorrow. i rekon it could be sticking open.

 

cheers for all your help andy :duffer:

 

alex

yay got it sorted :D took hte air reg off and cleaned it and my can now idles sweetly. guess it must have been sticking. very happy bunny now.

yay got it sorted :D took hte air reg off and cleaned it and my can now idles sweetly. guess it must have been sticking. very happy bunny now.

 

Hi alex,

 

Have been having similar probs. removed and cleaned iav but still a bit rough. Where abouts is the air reg and is it easy to remove

 

 

thanks

 

Nick

Hi alex,

 

Have been having similar probs. removed and cleaned iav but still a bit rough. Where abouts is the air reg and is it easy to remove

 

 

thanks

 

Nick

HTH :D

HTH :D

 

Thanks mate,

 

Hope it sorts it cos i'm getting sick of it now. :confused:

 

could be sledgehammer time soon :cry:

Hi alex,

 

Have been having similar probs. removed and cleaned iav but still a bit rough. Where abouts is the air reg and is it easy to remove

 

 

thanks

 

Nick

hi mate, its a bit tricky to get to as its right at the back of the engine and one of the bolts is difficult to get to but if you have a small rachet handle and a deep 10mm socket you'll be fine. here's a link that should be helpful.

 

http://www.es-ab.se/z-car/IdleTech.html

 

if that doesn't help try cleaning the throttle bodies.

 

hth

 

alex