Jump to content
SAU Community

Recommended Posts

Fellas,

Yesterday was quite hot in melbourne and my engine temp reached 86c which is warmish but the car still ran fine... Today when i went to drive my car the idle is very irratic. when the engine is at operating tempreture the engines idle goes from around 900-1400rpm by itself... Constantly goes up and down. I have checked most of the electrical connections and most of my hose connections and yet and still have no cure....

Any help would be much appreciated

i have a 96 mdl r33 turbo manual with a Power FC computer

Cheers

Link to comment
https://www.sau.com.au/forums/topic/59049-idle-is-up-to-shit-help/
Share on other sites

Hey mate,

Not sure whether i completely understand your problem, but it sounds like a similar problem I had... I suggest you check the harness running in2 the ECU, because that was my problem...

The RPM signal was cut, and re-soldered but a very average effort so when it got warm the wire's would expand then when it cooled it would only contact every so often so it would be unstable.

The wire colour is yellow with a blue strip running through it...

Hope this helps but not too sure because I'm not sure whether the harness was changed with the Apexi FC...

Goodluck mate,

Let me know how you go!

the problem seems to be related to engine temp... car idles fast when its cold because its on the cold start procedure, when the engine temp gets to 60c the engine note changes a little and as soon as it hits 68c the idle goes all funny.... from 1200-1600rpm.... up and down up and down constantly.... When I turn the car off and restart it straight away at operating tempreture the engine sits on 2000rpm for around 5 seconds and the drops to 1200rpm and revs up to 1600rpm up and down.... Its really giving me the sits...

It didnt do it yesterday but today i did.... Very very strange

Make sure that you have a fully functioning genuine Nissan Thermostat.

Rated at 76.5degC (stamped on it) $30 from Nissan if thats the problem.

The thermostat is designed to commence opening at 76.5degC and be fully open at approx 90degC.

So yeah, the temp should be within this mark when at operating temperature.

Also with age the Clutch Fan can be engadged all the time, and not allowing the motor to warm up properly.

The clutch centre is viscous type, and should only tighten up when its warm.

And the last thing, make sure the guage is right that you have the temp reading from.

Does it use an independant sensor or is it piggybacked to the factory sensor?

If its piggybacked you can get wrong readings.

I would consider 86-92degC normal operating temp for these motors.

86 cruising

92 idle with air-con on + hot day.

If its way lower than that, you are going to get bad economy and accelerated engine wear.

Is that for a RB25det only? because my R32 RB20det sits on 78degC for normal driving and the highest ever temp was 86degC in stinking hot heat with a full car load.

Thats a general rule of thumb for most motors.

78degC sounds preety fine to me.

I mean if it were lower than the thermastat temperature then it would be a problem.

i.e If you said it was running at 50degC all the time, then there would be a problem.

  • 3 weeks later...
Try cleaning the AAC valve. Check the TPS throttle-closed position.

sorry to dig up the thread again but I have been having issues with idle lately also.

Each time I disengage a gear and return to neutral, ie when stopping my revs seem to jump up a couple of hundred rpm. I have pulled apart and cleaned out the AAC Valve numerous times in the last 12 months so it must be something else, any ideas?

Where should the TPS position be when closed? Is there a general rule like TDC or something?

Thanks

Dale

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • What bedding in procedure did you use?   When you say stutter, what exactly do you mean? Like it feels like someone letting go of the brakes momentarily and regrabbing them again to get you to stop? Re-reading your post, and that is what it kind of makes me think you're explaining, like theres a little bit of a jolt, likely just as you're reaching a stop. I've only had this issue once. And if its caused by what caused mine, you will want to get the car up on stands again and check it over. Mine was a case of a caliper mounting bolt coming out and letting the caliper rotate on the other remaining bolt and gave play in a wheel as it came to a stop. But not every stop either!
    • Yeop... binned it   This will be a summary will not many pics atm and cbf  Fixed the samsonas - it was totally munched Put a new precision 7675 T4 on with proper split pulse mani Got to Sydney to get to car - drove to canberra to get racecar - drive back to sydney that night Next day all day at Plasmaman putting on new clamps cleaning some things up and adding another large engine oil cooler sitting at the rear above diffuser to keep things cooler Next day - Tuesday - on Dyno - killer wikid awesome pumped out really good numbers - more mid range and on lower boost levels Wednesday - first prac - all day again getting the suspension right - had to borrow front suspension again - out do a lap come in - out do a lap - in - what i had just couldnt handle the load at the more consistent higher speeds - got a lap in at the end of the day that was pretty reasonable  Put it this way that lap wouldve had me in 4th in Pro am for the whole event - with only 700 hp and used tyres Thurs first official prac day - lap out warm up - then entered a hotlap with above setting and 80% effort took corners 1,2,3 and into 4 car felt awesome -  rear came around out of nowhere bang into the wall near front on at whatever 140 kmph Done, over, gone Just one of those how did that happen apparently as all indications show nothing out of the ordinary Got to spend the rest of the time at the event like I hadnt done before - was actually Ok mainly as I had my family and my boy is 9 and got treated like a rockstar Long trip home, lost a trailer wheel in nowhere land, X5 airbag suspension gave up half way across nullabour and rode on bumps stops (its now completely fine) had to do a 19 hr drive day on day 3 as accommodation got screwed up so just had to keep driving till found a town with some Now to reassess - hopefully the motor and other things are OK but yet to be seen too. There is no easy fix there is no i'll just order that part and get it sent - we'll have a talk to people see what can happen and what the go is but at minimum its rebuild from scratch struts forward and alot of time effort and $ should and if I return and if but maybe/ when  I have the cage tied into the front strut towers - if I didnt have that things couldnt been worse you can say its just a front end but if you know what goes into these cars... you'll know what that actually means in reality   Car was very fast. Disappointing we just didnt get to show it Effort doesnt win you races though     Apparently this is motorsport !  
    • Thanks, will do that.  Thankfully they still feel great.
    • Yeah man, absolutely. You can try pushing me all the way in swapping the R34 for an E9x M3 
    • It's almost certainly going to be some amount of pads compound transfer onto the rotors. It will probably go away after you've run them for a bit. If not, pull it all out, lightly sand the rotors, scuff the pads, and rebed.
×
×
  • Create New...