GTR Forum banner

41 - 51 of 51 Posts

·
Registered
Joined
·
4,146 Posts
Plugs look fine mate :)
 

·
Registered
Joined
·
4,892 Posts
Discussion Starter #42
SimonM said:
All the coils should look like that last pic you posted, that is the spring inside the coil that makes the electrical connection to the spark plug.

BTW you need to use the macro function on the camera when doing close ups so that the object is in focus and not the floor. :D Looks like a flower symbol on my Fuji.
Cheers Simon :) Yeah - I had the flower symbol thing on but as I have no garage my hands were a bit cold so may have had a teeny bit of camera shake :D

Re. the coils suckers things - all but one look like the first picture with the metal tip inside the rubber sleeve. Cyl 6 is the only one to have a bare spring. Surely 1-5 aren't wrong with 6 right?
 

·
Registered
Joined
·
4,892 Posts
Discussion Starter #44
Righty ho then.... bit of an update. Having littered the Tuning & Maintenance section with new threads left, right & centre I thought I'd better come back to the original one and update it rather than start ANOTHER thread! :D

When I start my car from cold, the idle sits around 960rpm. After 60-90 seconds it rises up to around 1,370rpm and sits there. If I blip the throttle the idle dropped back down to circa 960, then after a few seconds it crept back up to 1,370 ish. If you listened you could hear one turbo chuffing and then the other chuffing back, over and over again with the sounds coming from the air filters. The idle itself was also very lumpy when the engine was warm. There also appeared to be a slight misfire.

As anyone who's had an idle problem on an RB26 will tell you, tracking it down can be a nightmare :( Progressively I've gone through the following:

- Replaced filthy air filters with spanky clean new ones (A'PEXi). This made the turbo chuffing much more pronounced, probably just because it wasn't being muffled so much by the clogged up old filters.
- Checked AFM voltages. Although at idle AFM 1 reads between 0.7v and 1v (give or take) and AFM 2 reads around 1.3v, when you open the throttle to around 2,000 rpm both AFM readings rise aand hold within 5% or so of each other so they look ok. Removed the AFMs and cleaned 'em with brake cleaner anyway.
- Checked lambda voltages on Power FC Hand Commander. They were acting very wierd - when warm O2 sensor 1 read circa 0.04v and numer 2 hovered around 1v. This looked very very wrong so I tried turning off the O2 feedback via the Power FC. It made no difference to the idle :( However generaly concensus was that one of the lambdas was [email protected] but as you can turn O2 feedback off via the PFC I decided not to bother removing / cleaaning / replacing them as they were redundant.
- Removed the intake pipework to try and see if the turbos spun freely as aa sticking turbo could cause the chuffing noise and bad idle. Could only get my finger to the impeller of the front turbo but it span freely...
- Removed the manky old big single GReddy atmospheric blow off valve that had come with the car and fitted a set of factory recirc BOVs. This immediately stopped the turbo chuffing, so it looks like the big single atmospheric GReddy BOV was leaking.
- Removed coil packs and plugs, sprayed inside the rubber coil tips with WD40 and wiped down the iridium plugs to remove any excess soot / fouling.
- Sprayed round all the intake pipes with brake cleaner listening for any rise in idle (which would indicate an intake leak). Couldn't hear any.
- Suspecting a faulty Power FC I removed the PFC unit and refitted the factory ECU and carried out a sensor check - all sensors checked out ok. Interestingly enough the factory ECU, although lumpy, gave a more consistent idle and I didn't see the idle rpm rise up to circa 1,300-1,400 or drop back when the throttle was blipped
- Refitted the Power FC and tried a spare set of coils for cylinders 4,5 & 6. Made no difference to the 'misfire'.

Suspected a possible faulty throttle position sensor I started the old girl up again today. From cold start she idled at around 960rpm. Throttle voltage was circa 0.39v. Then after 60-90 seconds the idle rose to around 1,300rpm (ish). If anyone's ever watched the idle on a Power FC they'll know that it doesn't sit at a steady figure - it hops around, hovering around the target rpm. However the throttle position sensor voltage never changed, so I guess we can rule that out.

Still, I let the car run up to temperature. I experimented with different settings on the PFC. What I DID find was that with the O2 feedback activated the idle, although lumpy, was much more stable than if I turned it off. When it's off the idle fluctuates up and down alot more, like the engine's trying to find a happy medium but can't. With the O2 feedback OFF the O2 readings sit around 0.02-0.04v each. However with it turned ON O2 sensor 1 sits around 0.02-0.04v but O2 sensor 2 stays mostly around the same voltage but momentarily hops up to 0.7, 0.8 or even 0.9v sporadically.

Looking at the Rev/Idle setting I have, at this point, admit that I can't read Japanese(!). There are 5 settings in the Rev/Idle menu. These are:

Rev limit 8700
F/C A/C (Japanese symbol) 1690
F/C A/C (Japanese symbol) 1200
Idle A/C (Japanese symbol) 1050
Idle A/C (Japanese symbol) 1000

When warm the idle seems to be governed by the second setting from the bottom. If I raise or lower this then the idle rpm goes up and down accordingly, and I have to admit that once warmed up the idle will hover around 1050rpm (which can only be a good thing!). So - can someone explain what those four Rev/Idle menu items are (other than Rev Limit)?

Furthermore, the 'blip the throttle and watch the idle drop then climb back up' doesn't happen once thoroughly warm.

My main grumble now is that the idle itself is much rougher than I suspect it should be. The closest online media I've found to give you an idea is here: - http://media.putfile.com/Lumpy-Cams

Although there's no visible change in idle speed, there are definitely two distinct 'phases' to the idle. The first is the slightly higher pitched 'brrrrrrrrrrrr' then followed by the lower pitched 'whum-whum-whum-whum-whum'. The 'whum-whum' phase actually rocks the car slightly but noticeably from side to side. That can't be right, surely?

The idle cycle is 'bbrrrrrrrrrrrr whum-whum-whum-whum-brrrrrrrrrrr-whum-whum-whum-brrrrrrrrrrrrrrrrr-whum-whum-whum....etc.etc.' I've been told by several tuners that when properly mapped 264/264 cams should idle just as smooth as factory cams, so this definitely ain't right.

Any thoughts?
 

·
Registered
Joined
·
1,166 Posts
Well the options are:

Rev limit (!!)
Fuel on rpm with ac (This turns the fuel back on when coming from DFCO)
Fuel on rpm without ac (As above)
Idle Speed ac on
Idle Speed ac off.

Is AC on when idle speed is fluctuating? In the ETC menu can you see the AC switch cutting in and out when AC is turned on (does the circle highlight)? Does it cut in and out when the AC is off?

Have you reset the PFC map by any chance?
 

·
Skyline Section Manager
Joined
·
11,872 Posts
IIRC, you need at least 300rpm difference between F/C settings and idle settings.

Try 1400 for the top 2 and 1000 for the bottom 2
 

·
Registered
Joined
·
4,892 Posts
Discussion Starter #47
ExScoobyT said:
Well the options are:

Rev limit (!!)
Fuel on rpm with ac (This turns the fuel back on when coming from DFCO)
Fuel on rpm without ac (As above)
Idle Speed ac on
Idle Speed ac off.

Is AC on when idle speed is fluctuating? In the ETC menu can you see the AC switch cutting in and out when AC is turned on (does the circle highlight)? Does it cut in and out when the AC is off?

Have you reset the PFC map by any chance?
What's DFCO? Deceleration Fuel Cut Off?:confused: Any chance you could quickly explain to a thicko why you'd need a different rpm in this scenario?

Regarding the A/C - for all these tests just assume that the A/C is turned off. I have turned it on now and again ust to see the effect withthe extra load but for the moment I'm ignoring it.

Will check the A/C switching tonight - couldn't tell you off the top of my head whether it switches on & off on the Sensor Check menu or not...

I haven't reset the PFC at all either. I have no way of saving my map (!) so resetting it would be a teeny bit silly at the mo, yes?:D
 

·
Registered
Joined
·
4,892 Posts
Discussion Starter #48
R32 Combat said:
IIRC, you need at least 300rpm difference between F/C settings and idle settings.

Try 1400 for the top 2 and 1000 for the bottom 2
Cheers matey - will change these around tonight as well. What happens if you don't have 300rpm difference between F/C and IDLE settings? (please God, tell me it causes all my problems and it's as simple as that!! :D:D)
 

·
Skyline Section Manager
Joined
·
11,872 Posts
My setting were

7000 rev limit
7000 Fuel is never cut off. It pop and bangs on the over run
7000 Fuel is never cut off. It pop and bangs on the over run
1100 A/C idle
1000 Idle

This works..:cool:
 

·
Registered
Joined
·
4,892 Posts
Discussion Starter #50
R32 Combat said:
My setting were

7000 rev limit
7000 Fuel is never cut off. It pop and bangs on the over run
7000 Fuel is never cut off. It pop and bangs on the over run
1100 A/C idle
1000 Idle

This works..:cool:
Ree-eee-eeeallyyyy???? So settings 2 & 3 will produce large flames pops 'n' bangs on the overrun if set high (like yours at 7,000)??

Time for a play :D
 

·
Registered
Joined
·
4,892 Posts
Discussion Starter #51
Well well well....

You have to bear in mind that most of the tinkering I've been doing recently has been driveway-based and the old girl hasn't really seen the road for a while.

I set the F/C speed on the Rev/Idle section of the PFC menu to the same rpm as my rev limit - 8,700. Left the idle at 1,000 (1,050 with A/C on) and started the old girl up. As per, she start at 960rpm ish then after a minute or so rose up to 1,350ish. Touch the throttle and it dropped back to 960ish, but after 5-10 seconds it rose back up to around 1,360 again.

So I took an purely scientific standpoint and decided "F**k it."

Warmed her up and took her for a gentle drive up and down the dual carriageway - GENTLE drive - to thoroughly warm her up as she's hardly moved for a while. Once the engine temp reached 80 degrees I took the opportunity to give it a little welly just to see how she liked it. Boost was set at 0.8bar just to be safe (peaked at 0.88 momentarily).

Once she'd shaken the dust off she seemed very happy to be stretching her legs. Few more bouts of boosting and all seemed ok so trundled back home and sat on the driveway to check the peak PFC readings.

Boost peaked at 0.88 bar, injector duty at 49%. Lo and behold, when sat on the drive having been nicely warmed up she idled at smack dab on the nose of 1,000rpm. Purrrfect.

Yes the idle is still quite cammy / lumpy but it's tolerable. The idle problems seem to therefore be isolated to cold idle, which is ok I guess as so long she runs ok when warmed up I can live with that.

My money's on the old atmos BOV being the culprit, but it obviously hasn't done any harm to replace the air filters, clean the AFMs and spark plugs and although it's been enourmously frustrating / depressing I've at least learned alot about the PFC, the engine and the idle control systems. Never a bad thing!

I'll stop my whinging now ;) (for the time being) although once I've paid for the wedding, fitted my Bosch fuel pump and my replacement Blitz atmospheric BOVs I'll be looking to get the car remapped. If the lumpy idle and poor cold idle STILL can't be resolved then, I guess I'll be picking everyone's brains again :D

Cheers for all the help, info, advice and generosity guys :D

Jim
 
41 - 51 of 51 Posts
Top