Hello, Been having this problem for a while now and its getting worse doesent matter if its warm or cold engine but runs better when warm... Just! on tick over the engine revs are up and down and then goes back to normal for a while then same again I could rest foot on gas at 2000rpm and when the lumpiness comes back the revs drop back under 1000rpm even though my foots in same place, when you drive it its fine for a short while between lumpiness and sometimes you can hear some det going on under bonnet. I have replaced the connectors on temp sensor but makes no difference.

Anyone got an idea to what it is??

heres a vid of the rev counter,

Try testing the connections on the CAS, TPS and make sure the PTU is correctly connected.

 

Also give the Idle control Value a clean after you have cleaned the throttle bodies.

 

The problem with these cars is that one dodgy signal form a sensor can apeear in a number of different ways.

 

If you do that lot and still have no luck then see if someone near you has a conzult they can plug in to see if they can find any faults.

Try testing the connections on the CAS, TPS and make sure the PTU is correctly connected.

 

Also give the Idle control Value a clean after you have cleaned the throttle bodies.

 

The problem with these cars is that one dodgy signal form a sensor can apeear in a number of different ways.

 

If you do that lot and still have no luck then see if someone near you has a conzult they can plug in to see if they can find any faults.

 

Hello mate im going to be dense now!! where do I find these lovely 3 connectors?? the throttle bodies were cleaned about 3000 miles ago when I had the cambelt done.

cheers for your reply!!

This seems to be a big help! http://www.twinturbo.net/nissan/300zx/FAQ/FAQpages/hesitate2.html and its only on a sticky thread on help and advice!!

Nice post you found there.

 

If you still can't find any of the bits I mentioned, look at this thread, that we did about 5 years ago.

 

http://www.300zx.co.uk/forums/showthread.php?t=26120

I have had a irratic idle and it's solved once cleaning the idle control valve. However the base idle wasn't as low as yours. It was ranging from 750rpm up to 1700 rpm

Nice post you found there.

 

If you still can't find any of the bits I mentioned, look at this thread, that we did about 5 years ago.

 

http://www.300zx.co.uk/forums/showthread.php?t=26120

 

thats handy! I might save that!

I have had a irratic idle and it's solved once cleaning the idle control valve. However the base idle wasn't as low as yours. It was ranging from 750rpm up to 1700 rpm

 

Where do I find the idle control valve mate???

this is a link to a guide on replacing it. You need to remove the pipe and spray some carb cleaner in it. Not too much though.

 

When you re-connect the pipes it will burn the cleaner through for a few secs then settle

 

http://www.twinturbo.net/nissan/300zx/tech/iaa/iaa.html

this is a link to a guide on replacing it. You need to remove the pipe and spray some carb cleaner in it. Not too much though.

 

When you re-connect the pipes it will burn the cleaner through for a few secs then settle

 

http://www.twinturbo.net/nissan/300zx/tech/iaa/iaa.html

 

Excellent mate will try that, I have checked all the other connectors and it makes no difference so fingers crossed its the one your talking about???

could be that. You may then need to re-set the base idle to 750-850 rpm. There are guides on that too.

First thought is CAS connector too

First thought is CAS connector too

 

That was the second one I checked even though the connectors were very brittle the male/female connectors inside were like new.. But still the zed shifts! and had a little test when I had a run in with a Honda integra GTR V plate about 30 mins ago up Cheddar Gorge (very nice and dangerous road! rolled a car up there once!!) but it was no match for the zed put it that way!!!

have you done an ECU diag?

have you done an ECU diag?

 

I done one ages ago now when it was doing it very little, strangely enough I was thinking of doing that today! but with 3 kids just doing that simple job takes ages im forever getting hassle off them!!! now there in bed the wife has taken it to do her night shift, her motor got broken into last week so just sat there at mo!

Think it could be wise to do the ECU test?

had a little test when I had a run in with a Honda integra GTR V plate

 

They dont even make GTR????? Type R is the one!!! :mac1:

paul at swz is just round the corner from you mate he's a ver friendly and helpful guy , mie be worth popping round to see him :)

paul at swz is just round the corner from you mate he's a ver friendly and helpful guy , mie be worth popping round to see him :)

 

yeah iv been round there a few times for parts very handy to have near by! we dont get enough zed garages! if I cant sort the problem then a consult down swz if need be( if he does them? ) anyone have an idea at what the cost of a consult is??

i shouldnt think it would cost much more than £20, my 1st consult check cost me nothing at Ultimate zeds in Gloucester, but any more checks after costs about £20, but i maybe wrong , if Jonzed32 se this post maybe he'll tell you exactly what they charge

i shouldnt think it would cost much more than £20, my 1st consult check cost me nothing at Ultimate zeds in Gloucester, but any more checks after costs about £20, but i maybe wrong , if Jonzed32 se this post maybe he'll tell you exactly what they charge

 

I was expecting more than that! around £60 maybe?? not a bad price! cheers Forge 300zx!