Skyline R33 S2 Running Rich Bad Fuel Economy Etc

[GTSBoy]

Most bov's are open at cruise due to the vacuum, unless they have the stiff spring fitted.

I would have said so for OEM recirculating BOVs, but not for aftermarket ones. More to the point, when you are at cruise with some manifold vacuum, an open atmo BOV will actually cause lean running because it's an inward air leak. And if you are on boost, then it won't have vacuum on it so it won't be open.

[scotty nm35]

I have seen it many times with the Turbosmart race Vband bov's, they are shipped with a soft spring and you need to replace it with a stiffer one. Probably just another way for turbosmart to make some more money out of you. I have the Turbosmart Kompact on mine and it had the same problem.

[rondofj]

Ron,

A nearly stock R34 that gives fuel economy that bad and isn't being thrashed around hard ALL the time does not need a tune. It needs whatever the problem is fixed.

My Neo is about the same as yours and I can easily get >400 km/tank. In fact, the last 4 tanks have been about 12.5 l/100km, and the 4 tanks before that (before it got quite as cold) were all <12. I expect that to get better once I tune it, although the extra boost will probably cost me in tyre smoke. Nevertheless, my economy is as bad as it is because the majority of my miles are start stop rush hour traffic. So I cannot believe that there's any good reason (apart from a sensor type problem) for your car to use as much juice as it does, and I definitely do not believe you cam make it go from where it is now, to decent-good fuel economy by tuning it. You will only likely be able to get it from where it is to merely terrible.

GTSBoy I dont think you know that my car is already running Nistune and is tuned at 13psi on the stock turbo (yes I know how lame is that), hence the reason for me being pretty sure its a tune problem, another reason I think its the damn tune is because it pulls timing / groans or something under hard throttle stabs and theres no power for 2-3 secs before it goes. But if I gently apply the throttle then it does go hard like it should, very different to a hard stab. Its well serviced and running good plugs coils filters oil O2 sensor etc, maybe the coolant temp sensor needs a look aswl..?

So yeah waiting on my wastegate from the US n ordering new turbo soon then its a install n full tune and hoping it will be da bomb..

[GTSBoy]

Yeah, I figured you'd had it tuned....but on the assumption that Jez tuned it, I wouldn't have thought it was tuned in a crap way, and it if doesn't behave well with Nistune running the show, it's hard to see how it can be made better with another tune. You'd expect that when it was tuned, the mixtures were reasonable and the timing looked sensible. If it is now crappy, then something has since gone wrong, yes?

By the way, I don't think 13psi on the stock turbo is lame. I have the stock turbo on my Neo and don't even have the factory boost solenoid, so I'm only getting 5 psi at the moment. I think the car drives well, and I look forward to when I get it through Regency so I can refit my boost controller and wind it up and tune it at 12 psi or so. 200 - 210 rwkW is plenty for making it (R32) a nice car to drive.

Definitely get the coolant sensor checked. They do fail. Can you hook up a consult cable/scanner/Nistune to see what the ECU thinks the temperature is when the engine is all warmed up? I'd expect it to think it's <60°C by the fuel usage you report.

[WMDC35]

as gtsboy says, try the coolant sensor for the ecu, the 2 pin sensor at the front of the intake manifold, prob red on a 33

[rondofj]

Yeah, I figured you'd had it tuned....but on the assumption that Jez tuned it, I wouldn't have thought it was tuned in a crap way, and it if doesn't behave well with Nistune running the show, it's hard to see how it can be made better with another tune. You'd expect that when it was tuned, the mixtures were reasonable and the timing looked sensible. If it is now crappy, then something has since gone wrong, yes?

By the way, I don't think 13psi on the stock turbo is lame. I have the stock turbo on my Neo and don't even have the factory boost solenoid, so I'm only getting 5 psi at the moment. I think the car drives well, and I look forward to when I get it through Regency so I can refit my boost controller and wind it up and tune it at 12 psi or so. 200 - 210 rwkW is plenty for making it (R32) a nice car to drive.

Definitely get the coolant sensor checked. They do fail. Can you hook up a consult cable/scanner/Nistune to see what the ECU thinks the temperature is when the engine is all warmed up? I'd expect it to think it's <60°C by the fuel usage you report.

Unfortunately dont have Nistune software and the consult cable, so cant diagnose the ecu. When I got the car it was running better economy though not by much, I added bits like exhaust, fuel pump, ecu, fmic and then got it tuned, after the tune the economy didnt go better as I thought it should, it actually went down to what it is now but I didnt think much of it then as I was very new to Skylines and thought thats how it would be, now that Im familiar and see others getting 400-450kms to a tank, Im getting pretty frustrated lol. After all the servicing and adding new parts n filters, O2 sensor etc, its still the same, it could also be a coolant temp sensor or a vacuum leak maybe, which wasnt checked during the tune. Not sure if a vacuum leak or coolant sensor could worsen economy THAT much, though. So that doesnt leave much else to pinpoint I guess. AFM, CAS? I think these are ok.

I currently have 187rwkw and think its very lame after going for a ride in a 336rwkw demon thanks to Mick O haha. 2nd gear and a bit of 3rd is actually nice at this power level- 200rwkw..

[GTSBoy]

Well, here's my advice. Don't upgrade the turbo on that engine until you work out why it is a dog.

[DVS JEZ]

Ron bring me ur car and i will gladly check it out for free

Even the Ethanol cars i tune get alot better economy than urs.

But i have seen how u drive

And remember u had a stock dump pipe at the time of tune too which definately didnt help.

Have u upgraded it yet?

Have u replaced the 02 sensor? I have replaced an 02 sensor on a r33. Went from 300km to 450km economy.

Also may need to do a smoke test to be sure

[Birds]

Anyone with bad fuel economy in an R33...replace your O2 sensor if it hasn't been done in the last ~30,000km. They are seldom replaced in these cars, people just don't think of it as a normal servicing requirement. But when they shit themselves they cost you ~70-80km a tank and being located in the exhaust system, faults can be synonymous with exhaust changes or tunes that produce hotter EGTs. Have fixed many R33s by replacing the O2. It is a <$100 part and the first place I'd look if I had bad economy.

[rondofj]

Ron bring me ur car and i will gladly check it out for free

Even the Ethanol cars i tune get alot better economy than urs.

But i have seen how u drive

And remember u had a stock dump pipe at the time of tune too which definately didnt help.

Have u upgraded it yet?

Have u replaced the 02 sensor? I have replaced an 02 sensor on a r33. Went from 300km to 450km economy.

Also may need to do a smoke test to be sure

Thanks for the offer Jez, thats nice of you, yes I know that stock dump was a big power restriction as you said before and yes I changed it longtime ago with a jjr bellmouth AND a new O2 sensor. It boosts quicker and harder and I can feel a good midrange chunk just from that dump alone.. The economy however remained unchanged and I wouldnt be surprised if I was driving one of the most uneconomical cars in Australia I am slowly replacing a few bits of vac hoses here n there now with repco and supercheap crap? hoses just for peace of mind from vac leaks..

[DVS JEZ]

How far do u drive it each day?

[rondofj]

Not more than 10-15 kays

[DVS JEZ]

Ok so it sounds like the cold start may be too rich.

Is it stop start traffic?

[rondofj]

Ok so it sounds like the cold start may be too rich.

Is it stop start traffic?

It is sort of, what can I say, 5 traffic lights and bit of a crawl here and there, 3-4 roundabouts, Sydney has no room to enjoy your car, no peace... Dont know if the cold start could make such a huge difference to the fuel haha.. Maybe I need to have a look at my coolant temp sensor..

[wolverine]

If I can get 12.5L/100km with a GT3076/GT3040 turbos around Sydney then you are either the biggest lead foot in history or there is an issue with the car.

[rondofj]

If I can get 12.5L/100km with a GT3076/GT3040 turbos around Sydney then you are either the biggest lead foot in history or there is an issue with the car.

Sydney roads and 1 point left on my licence doesnt allow me to be a lead foot haha -- definitely a car issue..

[DVS JEZ]

Sydney roads and 1 point left on my licence doesnt allow me to be a lead foot haha -- definitely a car issue..

Did u only get 1 point after getting ur licence back? Or did u lose more since?

[rondofj]

Did u only get 1 point after getting ur licence back? Or did u lose more since?

I lost 12 points on one go on a double demerit weekend (normally 6), so have one left now.. Nice aye

You dont get any points back till 3 years from the date of offence regardless of when you get your licence back..sad.

Edited August 20, 2012 by rondofj

[Missileman]

In the last 15 years I've lost 3 points, all of which were last November, not long after I got my first Skyline

[DVS JEZ]

In the last 15 years I've lost 3 points, all of which were last November, not long after I got my first Skyline

Hahaha

Im the opposite. I normally lose points in a shitbox. Has been a while tho