Power Loss On Downshifts, Bouncing Idle And Slight Hesitation At Specific Rev Point -R34Gtt

[XKLABA]

I've had mine disconnected since 2008 and get upto 650km from a tank

If tuned right you don't "need" them

[rondofj]

650km.. Boy is that even possible. I struggle to get 250kms! Well I found that my dipstick doesnt actually smell of fuel, I was mistaken, but my fpr vacuum hose has a slight fuel smell, so will replace the fpr, the fuel damper vac hose is ok though. But then no fuel shoots out at idle and 2000-2500rpms with disconnected hose???? Is it possible that it only happens under boost at load?

Set the TPS to idle at 0.48V instead of 0.41, hard to get 0.45, its too sensitive. O2 sensor unplugged n switched off. My O2 voltage doesnt fluctuate with it connected at idle so its def shot.

I found that I have lost a lot of power when boosting since the last couple days and its started to get high knock levels 130-140 at 5000rpms in third which it WASNT doing before. AFM peaked at 4.955V, what could it be, I havent changed my setup but I did lose the grey TPS plug cap thats supposed to go to the auto transmission wire something (mines manual). So I have the brown n black TPS plugs connected but grey one just has wires running thru with the end cap lost, is this a bridging cap?? Knocking a sign of leaning out?

Edited August 8, 2014 by rondofj

[Dose Pipe Sutututu]

It's because you adjusted your TPS

Now it's changed your load scaling

[rondofj]

Well no I adjusted it after driving because I read it should be in the 0.45-0.5V range, if thats what it does then I should adjust it back to 0.41V?

[Ben C34]

If you change anything and it makes it worse it would be wise to return it to how it was.

[Dose Pipe Sutututu]

Adjusting it will change your load scaling

Load is determined by AFM voltage and TPS

[rondofj]

Ok so TPS will be adjusted back. One thing I can confirm my afm voltage always goes sky high usually 4.9+V under high boost/rpm - had to switch off the airflow warning check light in powerfc.

While at it, chuck a bottle o injector cleaner in the tank for peace of mind..

Edited August 9, 2014 by rondofj

[AngryRB]

thats exactly what I will be doing tomorrow morning - check for fuel in the reg and damper vacuum hoses. Hopefully I will find fuel and confirm a dead reg - can i use R33 reg on 34 /possibly wolverine's one or do I need a R34 one - wreckers or buy new? Hopefully no touch up tuning required, but how to check if its providing the req. fuel pressure under load - else it will lean out n go bang haha..

I do remember when DVS Jez had a go at my 'stock' car 3 years ago he mentioned the fuel pressure's playing funny and advised me to get a spare r34 reg, which I got thanks to Johnny, so the second time round I went up to Jez with the spare reg, we didnt end up fitting it cos it was alrite then.. Now I have to look for that little reg, dunno where I put it or if it still there lol..

And yes I use a stock 'crushed' bov like Ben C34 does.

You had the car tuned and apparently it is fine they keep saying, when they tune a car they have an probe up the exhaust yeah? So its hard to understand this fuel consumption problem unless they just tuned it mostly on a full throttle.

To get 18-20L/100km you'd have to be on the gas pretty heavy, if most of your driving is normal then surely the injectors arnt putting the fuel in, not sure if

a car would run if its injectors were open 70% all the time, you have 600ish cc injectors so unless they are more than 50% open all the time then it doesn't make

sense. The only way to use this much must be from somewhere else.

If the reg is leaking and getting worse, you'd have a a few very rich cylinders and maybe some very lean from less pressure ,eg cylinders 5 and 6 leaning

If the fuel return was hooked up wrong you could have a build up of pressure from fuel not being returned to the tank, at full vacumn this build up could be

relieved by being sucked thru the reg into the manifold from a shit reg and getting you your high fuel consumption.

If the O2 sensor appears to be acting weird then surely this is an indicator of an outside factor ( REG) that is leaking independently to the other

sensors etc, so trys to fix the overfueling but only adds to the roughness. A continual changing of the system to try and normalise and outside

fault?

On the dyno they assume that there is no leaking reg, and that each cylinder gets the fuel they are programing, not sure but if they are using the

exhaust probe to check the fuel mixture they could be tuning it thinking its ok but in reality its false because the regs adding fuel too. When on

dyno you'd think this sort of fuel consumption would be obvious, and could diagnose it by engine braking and checking the fuel mixtures etc.

just a few ideas

Edited August 9, 2014 by AngryRB

[scotty nm35]

You can't clean injectors in the car very easily, and some have filters inside which require them to be backflushed. If you were at all worried about them you will need to get them on a flow bench to rule them out.

So when are you looking at the intake?

[GTSBoy]

Another thought. Z32 AFM is supposed to be good for 550HP. Is this car making >300rwkW? Are we suspecting a non-genuine Z32 perhaps also?

[rondofj]

Im suspecting the afm all along, its supposedly a genuine used z32 imported from the US, looks legit with orange sticker, mesh etc. Might post up pics later. Can you not block off the sensor element with a tab glued to the rear? So it reads one way only.

Got the boost leak tester out and found 3 more leaks at 14-19psi- 2 cooler joiners and one brake booster hose, its pretty minor, doesnt froth up hard from the soapy water, just very light frothing/tiny bubbles.

Set TPS back to 0.41V and got german Liquid Moly injector cleaner in the tank. Smells exactly like kerosene that I paid $16 /300ml for! Car still doesnt run right down low, doesnt sound and feel happy. Am not so worried about the power loss on shifting, moreso the running crap/no power, excessive fuel useage. O2 is disabled AND disconnected. What the hell could it be apart from afm? Intake pipe mod will come AFTER i solve this problem first,.

One thing I remember 3yrs ago without the z32 and 630ccs on a stock 208rwkw car I was still returning 16-17L/100kms. I had the 255l/hr Walbro pump/(with direct voltage feed) from that time. Now the economys shot up to 20-21L/100kms, and inconsistent unhappy car- was same with Nistune.

[Dose Pipe Sutututu]

Buy a wideband, forget about spending $100 on another boring half homo narrowband. Might as well not run one.

Without reading o2 all your hard work diagnosing is just a waste.

[rondofj]

I can tell you fellas one thing- switching off AND UNPLUGGING the O2 sensor in my car isn't a good idea at all (shit tune???!), it starts knocking with really high levels on the FIRST high boost pulls, and knocks at 5000rpms+ pretty early. Plug it back in and its all good, no knocks so far. And driving normally 60-80kmh, the O2 voltage fluctuates betwn 0.36-0.42ish volts, then after sometime it gets to the 0.68-0.76V range thats when it gets 'sticky', jerky, hesitating/ rough. So I will get a new bloody O2 sensor n be done with it. Cos O2 off dont work on my car too well to convince me.

Am going to fit new joiner where boost leak was, sand the ground point properly and remove the bov blockoff plate. And will look into a tailpipe wideband sensor/gauge.

[Dose Pipe Sutututu]

That makes no sense

The factory narrowband has zero bearing on boost.

It doesn't trim fuel when you're on power.

[Dose Pipe Sutututu]

Also if you have a leak on boost your car will run richer

[rondofj]

My leaks were minor- tiny frothy bubbles, sealed now with new joiner and tightening, but apart from that, yes thats my experience with this frigging O2 sensor. Will a r33 NTK one fit? R34 one cost $100 more for a plug the only difference I think. Anyways the bov block plates gone and I've sanded the ground point at battery to chasis. At least theres a peace of mind that all these friggin areas /sensors of the car have been looked at/sorted.

Edited August 9, 2014 by rondofj

[rondofj]

My z32- and how its wired to neo wiring

[Ben C34]

For such a critical sensor that wiring totally sucks.

[rondofj]

Whats wrong with it? Its soldered inside those taped bits

[GTSBoy]

Totally unprotected. Should be wrapped up and strain protected.

And, for an AFM that is supposed to be new....why has the lid been stuck back on with silicone?