# cranky in the summer sun



## kismetcapitan (Nov 25, 2005)

During the summer, it's starting up again. The car is Unhappy. Once water temps get between 80~90 degrees and oil temps hit 90, and the car is sitting traffic, the rocksteady idle starts to waver, the car hesitates at part throttle off the line, and in general the car does not feel like itself with power a little off and the slightest rattle, barely audible, which is probably the Poncams but having spun a bearing last year any rattly sound makes me nervous as hell. Although when I did spin the bearing, not only were the knock sensors going crazy, you'd have to be utterly deaf to not hear the Death Rattle.

And the car likes to stall when maneuvering around a car park, which I'm feeling is tied somehow to low voltage, although it will die once or twice while decelerating - clutch in, and the engine RPMs drop to 1000...and sail right past to hit zero :nervous:

Now at night, with cooler temps and less traffic and hence more air flowing into the car, no problems.

Now for sorting this out. I can accept that a tuned Skyline isn't going to be particularly civil in hot and stifling weather and painfully slow traffic jams. On the other hand, I've spent a pretty penny on cooling (radiator and oil cooler) and I don't see temps over 90 degrees, ever.

There is probably a huge difference between fluid temps at 90 while booting it on a track, and 90 degrees while motionless in a sea of cars inching their way through Seoul. So that means airflow to the intakes is the issue? Should I try to wall off the air filters, or route the filters outside and down, out of the engine bay (someone here did that, can't remember who but it was a slick install).

When the car becomes Unhappy, the idle AFR, which I've set to 15.3:1, goes WAY lean, leans out past 16:1. Adding a lot of injector lag to richen things up helps, but it's a pain, it doesn't work all the time, and of course that means my entire fuel map while on throttle is a full point richer (and crap, as a result).

Air flow meters? Intakes desperate to breathe fresh air instead of insanely hot and stagnant engine bay air? I know some of us run Skylines in perpetually hot climates, and in urban environments as well. Or the charging system turning to crap with the alternator baking? Voltages do drop a bit.

What have I missed in setting up my Power FC? Two summers ago I just put up with it and rode my bike as often as possible during the summer. Last summer the car was being rebuilt, so I had forgotten about how the car hates hot weather and slow traffic.

It's not a Lexus. But it is somewhat upsetting that while every car including the cheapest econoboxes idle away with cold A/C in traffic, while I have to lumber along, catching the lumpy idle to prevent the occasional stall and shutting off the A/C or stereo or both to let the car's voltage stabilize. I do have a plain old wet-acid battery, but it is HUGE, not the tiny compact battery most R32s have.

Any ideas?


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## jabran200 (Sep 5, 2005)

kismetcapitan said:


> When the car becomes Unhappy, the idle AFR, which I've set to 15.3:1, goes WAY lean, leans out past 16:1. Adding a lot of injector lag to richen things up helps, but it's a pain, it doesn't work all the time, and of course that means my entire fuel map while on throttle is a full point richer (and crap, as a result).


Does the PowerFC not have a water temp enrichment map? Use that rather then adjusting lag times as it will be perfect all the time in the cold and hot weather. I'm sure the PowerFC has this, It should also have an air temp enrichment as well and these are the ones that will help adjustment in different temps away from your normal 60-70 optimal temp.

I am actually going to make an air box for the HKS pod filters as it will defo make a difference to IAT readings.


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## kismetcapitan (Nov 25, 2005)

I'll give that a whirl, although I really need enrichment only at idle - if it enriches across the board then I go too rich on boost and lose power.

I think the car wants real cold air, and I think I've finally found my next project - true cold-air intake!


Or...I know someone that I could swap my Apexi filters for a stock airbox. Would I be insane to put in a stock airbox into my car??? The airbox is self-contained and does only draw air from outside the engine bay...


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## miragev (Apr 11, 2007)

jabran200 said:


> Does the PowerFC not have a water temp enrichment map? Use that rather then adjusting lag times as it will be perfect all the time in the cold and hot weather. I'm sure the PowerFC has this, It should also have an air temp enrichment as well and these are the ones that will help adjustment in different temps away from your normal 60-70 optimal temp.
> 
> I am actually going to make an air box for the HKS pod filters as it will defo make a difference to IAT readings.


i live in greece where the temps are 35 + daily 
i had idle problems last summer after fitting my z32 afm's it was hunting up and down at junctions on idle it was really annoying ..stalling when manuvering on my drive 
i did exactily what you suggested to kismet above i enriched the water temp map at three points and the problem was instantly solved i can't remember what the temp degrees say on the screen but the top 3 on both colums


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## jabran200 (Sep 5, 2005)

kismetcapitan said:


> I'll give that a whirl, although I really need enrichment only at idle - if it enriches across the board then I go too rich on boost and lose power.
> 
> I think the car wants real cold air, and I think I've finally found my next project - true cold-air intake!
> 
> ...


I'm not sure how the PowerFC's one works but it usually adjusts throrugh the range as the hotter temps affetc the whole map. Once you start moving you will drop back to normal temps almost instantly so the changes would be gone at the normal temps.


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## roadie (Feb 6, 2006)

Your idle timing may be too far advanced when warm. Try to use the hand controller and manually back off a few degrees on the inj/ign tab and see if the idle smooths out.


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## Asim R32GTR (Sep 24, 2003)

15.3:1 AFR at idle is way to lean. Especially with uprated cams.
Try setting the idle afr to around 13.8 - 14.... Maybe even lower... 

I have just put in step 1 tomei cams, 260 / 9.1, and i had to set my idle to 13.5 ish to get rid of the erratic idling.

Yes it runs a bit richer, but it makes the car a little smoother on idling. 

Asim


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## jabran200 (Sep 5, 2005)

Asim R32GTR said:


> 15.3:1 AFR at idle is way to lean. Especially with uprated cams.
> Try setting the idle afr to around 13.8 - 14.... Maybe even lower...
> 
> I have just put in step 1 tomei cams, 260 / 9.1, and i had to set my idle to 13.5 ish to get rid of the erratic idling.
> ...


Same here I've got 256 and 9.25 lift and it wont idle nice apart from around 13.9-14.2 or below. At 14.7-15.1 It sounds like it wants to die lol.

I think you should adjust the idle a bit first and see if it become better.


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## kismetcapitan (Nov 25, 2005)

my car, when warm (but not hot) idles very smoothly at 15:1. I set it there to "save gas" but now I realize how utterly pointless that is in a Skyline!

Didn't think about idle timing - mine is pretty advanced. I'll pull it back, see what happens.

I'll also dump more fueling on the idle portion of the map, but I'm also under the impression that the Power FC literally has a mind of its own when idling (when the TPS is indicating that the throttle is untouched).

I run without O2 sensor feedback so I'm always open-loop.

I'll go into the water enrichment table as well - good to hear that was all it took to sort out, for using Z32 AFMs in crazy hot weather. 35 degrees! I'd die 

But not today - it's raining like mad, so the car runs cool and happy of course with all that "water cooling". And I'm being a pussy - I just spent four nights detailing my car, spending a lot of time with rubbing compounds polishing everything out, then applying two coats of wax by hand - no applicator. grab a bit of wax, rub it in your palms to warm it up, then start working it into the finish. After all that, going into the rain seems mad (although the whole pojnt of a great wax job is to make the rain bead off elegantly...but then I won't take it into the rain? I make no sense sometimes...)


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## kismetcapitan (Nov 25, 2005)

well, that wasn't hard. Took ten seconds to dial in the water temp adjustment from the FC Commander, watching the wideband until it was just right. I fiddled a little more with idle fueling to bring it down to 14.5:1.

Car runs MUCH better now when heat soaked and miserable in traffic 

I'm going to fine-tune the water enrichment table later tonight. Rescale it (when am I ever going to see -30 water temp? never in this town, my car is always parked indoors), and bring the top temp up to about 100 degrees, and adjust accordingly.

Sure did the trick, thanks!


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## Asim R32GTR (Sep 24, 2003)

To be honest, you shouldnt need any watertemp enrichment from around 60C and up. 
Every car has a normal operating temp at around 80-90... some audi`s go as high as 95-100. 

Set the watertemp enrichment to 0 from 60-70C and up. And do the idle fueling in the fuelmap. 
Becasue if you by anychance reach the modified temprange when driving hard, it will start to ad fuel no matter what rpm youre at. 

Asim


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## kismetcapitan (Nov 25, 2005)

I'll give that a whirl, good point. On the street, if I can get full power going, I'm also moving fast enough so that my water temp is 70 and oil temp 80. But if I get to track my car, it may very well see higher temps and yes, I'll run rich and lose power.


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## skyline69_uk (Jan 6, 2005)

I had this exact same problem for 3 years, checked everything, hoses, turbos, PowerFC all the usual stuff. 

Two weeks ago the CrankShaft Vent Hose (Blowby Hose) showed a massive crack in it. Fixed this with insultion tape and ever since the car has run as smooth as silk (waiting on new hose from Nissan arriving).

I was told 3 years back by someone on the forum that his hose would be the problem but 2 mechanics and myself checked it and "visible" holes or crack could not be seen. It would appear that the hose had been breaking up thru age for a long time and when it got very hot it was expanding and the crack was changing the pressure in the hose, this makes the PowerFC hunt the idle.

Problem is now fixed  but took 3 years to find .


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## kismetcapitan (Nov 25, 2005)

Asim R32GTR said:


> To be honest, you shouldnt need any watertemp enrichment from around 60C and up.
> Every car has a normal operating temp at around 80-90... some audi`s go as high as 95-100.
> 
> Set the watertemp enrichment to 0 from 60-70C and up. And do the idle fueling in the fuelmap.
> ...


ah, now I remember why I didn't do this - I did it a couple years ago. I had to add so much fueling to the 2000rpm and under part of the map that, when the car was idling at 68 degrees (I've got a Nismo low-temp thermostat so water temp tends to lock in at that temperature), I had a 12.5:1 idle AFR.

What I think I'll do, since my car never sees over 75 degrees when I'm running the car very hard, is rescale the water temp scale so that I have correction points at 60, 75, and 90 degrees. I'll set correction to 1.0 for the first two, then have the curve ramp up to 1.07 (which is enough correction to make the car happy).

btw, anyone know the difference between the left-hand column of correction, and the right-hand side? Right-hand column values are all higher, but the difference shrinks as you go up the temperature scale. If I knew what they actually represented, I could adjust more accurately instead of stabbing in the dark...


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## kismetcapitan (Nov 25, 2005)

if the two columns are load based, I'm golden - set enrichment for low-load, but set high-load and high temp to 1.0 (no correction). I need to confirm that though...


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## miragev (Apr 11, 2007)

i maybe totally wrong here but....
i assumed that one column was for no aircon and the other is for when aircon is switched on as it loads the engine on idle ..


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## freakazoid3 (Jan 19, 2008)

skyline69_uk said:


> I had this exact same problem for 3 years, checked everything, hoses, turbos, PowerFC all the usual stuff.
> 
> Two weeks ago the CrankShaft Vent Hose (Blowby Hose) showed a massive crack in it. Fixed this with insultion tape and ever since the car has run as smooth as silk (waiting on new hose from Nissan arriving).
> 
> ...


Exactly which hose would this be then? 

As ever since I blocked the blowby hose from the balance tube and put the other 2 vent hoses from the 2 rocker-covers into a catch can my r32 tends the hunt when deccelerating and pushing the clutch and sometimes she even stalls


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## kismetcapitan (Nov 25, 2005)

argh. I delved deeper into the fueling, and to do it properly...I'm going to return the water temp corrections to stock, and completely remap the injector map, and then calibrate the MAF curve to match. My particular Z32s seem to be quite off in terms of indicated AFR and actual; reading too little air down low, and reading too much air up top (resulting in lean running at low airflows and sometimes bogging down with a 9.5:1 ultrarich mix on boost - needless to say, the car hits a brick wall in pulling power with that much fuel)

Still need to give the AFMs a cleaning, see if that might help any. There's no mesh to assist with laminar flow, but there never has been - I ripped out the mesh before they ever were installed in my car, and they've been running fine and dandy up to this point.


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## kismetcapitan (Nov 25, 2005)

one thing I definitely do NOT want to touch is the highway cruise - I've stumbled upon the magic combination of timing and fueling that completely eliminates shuffle and keeps the turbos at 0.2 bar positive boost while cruising at 50~70mph, meaning no lag on the highway when I give it some wellie to pass someone.

Just need to carefully map around that zone!


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## skyline69_uk (Jan 6, 2005)

freakazoid3 said:


> Exactly which hose would this be then?
> 
> As ever since I blocked the blowby hose from the balance tube and put the other 2 vent hoses from the 2 rocker-covers into a catch can my r32 tends the hunt when deccelerating and pushing the clutch and sometimes she even stalls


It's a hose about 1 inch diamenter that runs on the left side of and parallel to the engine block (nose to arse of car) if viewed from the front, about 1 foot long and bends towards the block at each end, one end (at the back) attaches to another pipe thru a 3-way junction.


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