Im having issues with idle. All of a sudden today the car was trying to idle at 600rpm. Then would stall.

 

Bit of history. The car had the water pump go about 4 month ago. The car never overheated. I only got round to replacing the water pump 2 weeks ago. and did the Cambelt tensioner idlers etc all at the same time. The other item changed was the PAS pump as this sounded aweful and was turning on the hicas light. The car when starting was a bit noisy from a sticking tapped but this cleared once warm as it had been sat but ran well.

 

The car pulls very well (better than before the work) and is still now it's idling bad.

 

Thoughts please where to start looking.

 

Thanks.

Any ideas????

I know this is gonna sound stupid but what petrol you using?

 

Used to happen to me quite a bit when i was usiong normal unleaded but then when i switched to Tesco Momentum 99Ron it all stopped.

 

Worth a try

 

Peter

Initially I would look at cleaning the various connectors under the bonnet,

particular the Yellow connector attached to the Auxiliary air unit. (Rear of the engine, right hand side as viewed from the front.)

Following that I would set the base idle, Remove the Yellow connector when running and set the idle to approximately 600rpm.

Re connect the yellow connector and the ECU should lift the RPM to somewhere around 850 to 900rpm.

Worth trying this first and see if it has any affect, let us know as there are numerous other things that may be at fault.

I give thes a go and see. What's the procedure to set the base idle???

Awesome bit of info on this in the FAQ section!:

 

http://www.300zx.co.uk/forums/showthread.php?117186-idle-control-valve-tech

Right I'm stumped at the moment.

 

TPS measure fine. When I take the IAA connector off I can't idle at all. Turning the screw makes no difference. It is turned out anti clockwise fully at the moment. Which I believe is max idle??

 

I get 10 ohms measured on the connector so that seems fine and when plugged in the car will at lease try not to stall.

 

The car if the throttle is open even just a little and held the car idles at 1100 fine and smooth with no hunting.

 

also has throttle is opened I can hear PCV valves click on both sides. Is lightly opened you hear them flicker. So although I might have week PCV valves (possible cause of another issue) its not where I think the issue is.

 

Could it still be my iaa valve?? Should I take it of and clean up all of it fully and see if it works?? as to gasket is this a stocked park by Nissan? or can I get it elsewhere? could I use silicon gasket? or a home made card gasket? or another option I have missed.

 

Thanks

I would take the valve off and give it a good clean up. It may well be gunged shut or open.

Before you go to far, take a look at all of the small black 4mm hoses,

sounds to me that maybe one of them might have come adrift somewhere.

Look at the bottom hoses on the valves first.

 

Sorry Steams, You must have just posted this as I was typing my reply up. Did not mean to contradict you.

Edited April 21, 201213 yr by redwine300

Before you go to far, take a look at all of the small black 4mm hoses,

sounds to me that maybe one of them might have come adrift somewhere.

Look at the bottom hoses on the valves first.

 

Sorry Steams, You must have just posted this as I was typing my reply up. Did not mean to contradict you.

 

No worries. lol It's certainly worth check for loose pipes etc.

Do you mean the 4 pcv hoses??? if so there all on fine from looks of it.

 

Cleaning the IAA seems easy along with all it's ancillaries. Just is the gasket nissan only part???

 

Interestingly the car always idled high. The screw was only about half a turn of fully open so this sticking might just be the issue.

 

Ps. Is there an easy way to adjust the screw with a battery in the way???

Ps. Is there an easy way to adjust the screw with a battery in the way???

 

that's the way i always do it.... a bit of messing about but I find a long small head flat head will do it... (and just to be sure, you are unplugging it with the engine off first)...

Do you mean the 4 pcv hoses??? if so there all on fine from looks of it.

 

Cleaning the IAA seems easy along with all it's ancillaries. Just is the gasket nissan only part???

 

Interestingly the car always idled high. The screw was only about half a turn of fully open so this sticking might just be the issue.

 

Ps. Is there an easy way to adjust the screw with a battery in the way???

 

No, he's talking about the vac lines that go to the solenoids. I bought my gasket from MJP in the traders section but you could probably make something up with some gasket paper.

might sound stupid but I had a similar problem on a 200sx air filter chocked

I would have thought that a dodgy maf would have issues on pull away and low revs????

 

Imm gonna try the IAA clean.. No harm in doing it. Then see how we go. Then I'll check the maf.

i would of said a vac leak

Right update.

 

Removed and cleaned the IAA and the other bit behind it. Both quite clean. Ohms on all check out so think the fine. Checked the hoses for leaks and the IAA unit. No further joy.

 

The car now is idling lumpy if it will idle. Also now lumpy up to 2k. Very up and down. I'm wondering if a coil pack is shot or my plugs are. Problem is I can't get my coils unplugged. Is there a knack. The bit that I would expect there to be a clip on is filled with rubber.

 

I did run the car with 2 coils lifted and that seemed to have no effect. I could hear a bit of sparking. Wondering if it still was feeding the plug. Surely not?? if this is the cas could I be running on only half and engine at idle???

 

Only other thing is my belt has slipped. As I said I changed the belt and it ran good for 2weeks before the problems hit. (funnily at the first site of rain.) could one bank be running a tooth out??? surely I would know if that's the case???

 

 

Thoughts and help and next step appreciated.