R34 Rb2530 Low Rev Problems

[lolo.37]

HI there,

Laurent from France

My RB2530 forged engine is now running but I can't make it run correctly under 1500-2000rpm on my R34 GTT.

At idle, when you Wide Open Throttle, combustion stops and engine stops.

It is hard to start to move the car from stand still. have to rev up a bit to make the car move.

The engine often stops when arriving at the red light.

After 2000rpm, it's driving perfectly on R34neo map

my setup :

R34 car and R34 wires

Forged RB30

R34 main pulley

R33 head with keeped VTC. R33 intake cam, R33 springs and valves.

R34 neo exhaust camshaft on hydro lifters. (only way to keep the plastic CAS for my R34 wiring loom)

R34 neo VTC on R33 camshaft (problem?)

MAF checked (actually runing the Neo one, Maf Z32 waiting)

Nistuned R34 ECU

Timing belt position checked 3 times.

TPS checked; under 0.3V at idle (On nistune, idle is ON when idle and not when not at idle)

Air Leaks checked by pressurizing the circuit. There is a very little little leak in plenum but pressure doesn't drop down fastly.

"rebuild" 750cc injectors

I planed to check the standard injectors and then a stock R34 ECU. After that i would guess a head problem (cam timing issues, backflow...)

Hope someone could see clear in my problem.

[The Mafia]

Can you get the person that did the nistune to have a look for you? Checking the ECU logs would give you a good idea to what is wrong.

Also, the user DVS Jez is very good with this sort of thing, you should contact him, or hopefully he sees this thread.

Welcome to skylines Australia

[KiwiRS4T]

The neo cam sounds innovative to say the least. Did it fit no problems? You could have used an R33 cas and just reversed the wiring to suit your ecu/loom. Can you tell from the dyno whether the VCT is actually working? I have an R34 LinkG4 in my RB30/25 and use an R33 CAS.

[lolo.37]

Seems very interesting

I'll send a PM to "DVS Jez"

Yes R34 exhaust camshaft fits perfectly on R33 standard head, nothing to change.

A friend of mine doubt of the cam profile between hydro and solid lifters. He say the "begining steep" is not the same on cam profile. And MAYBE it could open/close too soon/late.

I don't know if VTC is working. It is 432km that this new engine runs. I tried to unplug the VTC and as expected, nothing change. And I never been upper than 4500rpm low load.

Great new for R33 CAS fitted to R34 loom/ecu! I just saw that the plugs are totally the same. (I have a R33 CAS also)

So there are wires to reverse? Can you tell/show me which ones, plz?

Edited August 25, 2012 by lolo.37

[DVS JEZ]

Has the car been tuned?

What are the air fuel ratio's doing when the issue is happening.

Try bumping the latency up as this affects low inj pulse.

May also be an issue with the 02 sensors.

Send me the .bin file if u would like me to take a look. Also send a log file preferably with a wideband being logged.

dvs_tuning at hotmail.com

[KiwiRS4T]

Seems very interesting

I'll send a PM to "DVS Jez"

Yes R34 exhaust camshaft fits perfectly on R33 standard head, nothing to change.

A friend of mine doubt of the cam profile between hydro and solid lifters. He say the "begining steep" is not the same on cam profile. And MAYBE it could open/close too soon/late.

I don't know if VTC is working. It is 432km that this new engine runs. I tried to unplug the VTC and as expected, nothing change. And I never been upper than 4500rpm low load.

Great new for R33 CAS fitted to R34 loom/ecu! I just saw that the plugs are totally the same. (I have a R33 CAS also)

So there are wires to reverse? Can you tell/show me which ones, plz?

CAS types:

This is an R33 one (Mitsubishi) 23731 02U11

This is an R34 CAS -(Hitachi) 23731 5L 300

I don't think the wrong one would engage properly with the drive on the end of the cam so if it fits ok you could just try reversing the wiring.

R34 CAS

pin 1 = earth

pin 2 = power

pin 3 = 1 deg

pin 4 = 120 deg

R33 Cas

pin 1 = 120

pin 2 = 1

pin 3 = power

pin 4 = earth

And making it easier basically showing that:

1 swaps with 4

2 swaps with 3

3 swaps with 2

4 swaps with 1

[lolo.37]

Thanks KIWI,

I'll put the R33 cam with the R33 CAS (and also the R33 VTC to the R33 intake Camshaft)

Has the car been tuned?

What are the air fuel ratio's doing when the issue is happening.

Try bumping the latency up as this affects low inj pulse.

May also be an issue with the 02 sensors.

Send me the .bin file if u would like me to take a look. Also send a log file preferably with a wideband being logged.

dvs_tuning at hotmail.com

The car is just running on R34 neo standard map, modified K constant, tried different inj latencies. (inj given for 800, but correctly running at 1200 (narrow band O² sensor unpluged to find that value))

stock O² sensor (narrowband) seems fine (from the nistune french seller advice)

My PLX wideband is not linked to nistune but I'll try to synchronise a video with the log...

It'll be my first log, what parameters have I got to select? (TPS, O² sensor, injection, timing ???? ... )

Thanks a lot for all this help !!

Edited August 25, 2012 by lolo.37

[DVS JEZ]

Do it in stream mode. And get as many parameters as possible.

What are the afr's down low?

U say inj are 800 but had to set them at 1200, this tells me the k const and latency is incorrect.

Are u running the standard fuel pressure?

[lolo.37]

Do it in stream mode. And get as many parameters as possible.

What are the afr's down low?

U say inj are 800 but had to set them at 1200, this tells me the k const and latency is incorrect.

Are u running the standard fuel pressure?

here is my first log. (.csv) : http://www.2shared.com/file/y_OdOvVz/log1_2012-08-26_1448_37.html

And the Map I use : http://www.2shared.com/file/AJaAC_K2/RB30DET14.html

and a little video of how it does: http://www.youtube.com/watch?v=AHE9C8OPe4U&feature=youtu.be

As i said and what we can't see in the picture, when throttleing (under 2000rpm) and clutching to start the car, combustions often stops and have to pump the gaz pedal to start because it is very shaky with the twin clutch.

I couldn't figure how to use the stream mode. I was in consult mode to make this work.

I chose RPM O² maf and TPS.

A new symptom that appears now is the lost of torque sometimes that you'll see whith the O² curve.

The ambiant air is much much hotter than previous tests.

I will make another log file with filming the wideband. But you can tell me if you need other infos before I make this new log. (injection time? timing)

Only 4 parameters are logable at a time ...

[DVS JEZ]

Send me a pm later in the week i will take a look for u.

Got a few cars to catch up on atm

[Adriano]

It will be the neo cam using the hydraulic lifters, its like running a 300 deg exhaust cam. I think it makes the lifters pump up

[lolo.37]

I worked a bit on it today.

Puting the R33 exhaust camshaft

Also the R33 VTC instead of R34. (R33 and R34 VTCs seem to be the same with 20° but who knows... I want to be sure this time.)

Now need the electrical stuff to be done with the CAS. reversig wires.

I'm really hoping on this to make my car run properly !

[lolo.37]

HI again,

I finished the job and unfortunately it is not the solution.

The R33 exhaust camshaft may have make it better but not very sure of that

Here is a video of what it does :

The ECU light on the dash is because I suppressed the TCS motored throttle body and Position sensor.

Any ideas left?

[DVS JEZ]

I still seems like its in the tune. Im away from my laptop and shop today but will try and remember to have a look

[lolo.37]

Some more news....

The french seller of Nistune in France and who'll map the engine took a look at my log.

He told me I was very high in loads. but that could run. (RB30 engine for 25 ECU map maybe)

But more important, i have timings in map like 30-35* in low load/rev, and the ECU is sending only 19*

So he discovered i'm alway in knock maps.

He told me I may have tightened my sensors too hard. As is only needs 20N.m.

I unplugged the knock connectors and i'll make a test soon but not sure it will solve the problem.

Something maybe important. Before I made this swap, I broke my neo 25 using GTX3071@0.9-1bar making 390hp at flywheel but with standard neo ECU

AFRs where good so I drove it. But no EGT mounted... Some hard driving made hi temp and knock.

I lost compression and blow-by took some oil out of the head by an unplugged vent.

Then with the wind in the bay, the oil got onto the red hot manifold. The car took fire.

Big fire but quicly estinguished with 3kg of powder.

No wire was cut in this because fire was only on the exhaust side. Some wire for valves (fuel vents or something) had hot but not cutted. And very few wires on this sideof the engine.

And those valve are not used now aswell as the TCS butterfly motor and sensor.

Maye useless but just to tell everything.

[KiwiRS4T]

Try a compression test to make sure everything is still ok?

[lolo.37]

done some weeks ago after the engine first started.

8 bars everywhere. CR is 8.2:1

Edited August 31, 2012 by lolo.37

[MrStabby]

No reason to suspect compression at this early stage. As Jez said "U say inj are 800 but had to set them at 1200, this tells me the k const and latency is incorrect."

So - when you changed the injector sizing in Nistune did you also correct the latency setting on the new injectors? IMO you should set Nistune to the correct injector size and try to get it running by playing with latency. If you can't find the latency specification for your new injectors, then just try increasing the latency which will make it richer at idle (assume you believe it to be too lean at idle - which would be my first guess).

[lolo.37]

It is correct at idle, it is only when you puch quickly the throttle. As in my first vidéo and also second with the gage.

I change injector settings on nistune. Found the theorical latency and applied it. The car wont start. By getting latency higher to 1200 or even 1400, then it starts.

Had to pass from 150 for the Kconstant to 200 also.

But when I'm driving stable, i'm around 14 to 15 AFR. And when pushing a bit more the throttle to have a bit of boost, i'm between 12 and 13 AFR. So its seem's very correct.

Edited August 31, 2012 by lolo.37

[lolo.37]

here is some updates :

I tried with unplugged knock sensors and it does the same.

I tried to plug R33 1996 knock sensors instead of mine. But they are not screwed on the engine block. Only signal and ground wired.

And it does the same

Here is my log with that setup.

http://www.2shared.com/file/GqyHgzgr/log2_2012-09-03_1728_23.html

I found I'm at 0 to 2 degrees of timing at idle. and more than 40 when driving.

I can't see clear now... Maybe it is someting i've missed on the engine but I don't know what... Or it is on the tune but there is no good map to make a setup of TPS vs pulsewidth...