Thanks Santa (the neverending trials of the 400,000klm, 400kw, RB30, manual swapped Stagea)

[Duncan]

Right, onto putting the bushes in. I can't see any feasible way to do this in the car than using a bush pressing kit or making the equivalent yourself. Either way, if you don't have this you are stuck without a working car now

I bought a bush pressing kit a few years back, and while I don't use it often, it is a life saver when I need it.

I put the bushes in the freezer overnight, not sure if it helped but they did go in easy.

This is the set assembled, ready to install.

The new bush is in the middle, and a cup (or flat plate) larger than the bush is required to push it in. On the front side, another cup or plate larger than the bush is required to stop it at the right place. A threaded rod goes in the middle with a nut at each end to do the pushing. In the bush kits, the nuts have bearings to help them turn, in the home made version you should use the biggest nuts and rod you can find, and grease the nuts well

From here, it is dead easy.....Turn the nuts until you feel the bush come up hard against the plate on the front. Voila, done. The bush sits well proud at the rear

And flush at the front

From there, assembly is the reverse of disassembly. Just remember to change the diff oil while it is on the floor to save future you frustration

[Duncan]

In hindsight, without a hoist, I don't think this is the easiest way to do it. 

Instead, I would drop the whole subframe.  Fuel tank does not need to be removed and access to the bushes would be much better. Plus, you can replace the all of the subframe bushes themselves at the same time, which is an equally painful and probably necessary job by now.  

To remove the subframe (short version).

1. Support the car by the sills

2. Jack under the centre of the diff.

3. Remove the rear calipers and support then on the chassis so they are not hanging by the brake lines. Undo the lower (or upper) shock mounts.

4. Undo the 3 wiring plugs for the ATTESSA pump, and the fluid feed and return to the boot reservoir. Undo the pressure line to the transfer case.

5. Undo the tailshaft

6. Undo the 4 subframe bolts and slide it down and out, and enjoy all the space to remove and install the bushes.

[Duncan]

One other thing to mention. Working on road cars is a nightmare compared to a nice clean race car. 450,000klm of dust and crap is baked onto everything. I cleaned up all the hardware in an ultrasonic cleaner, did a reasonable job with no effort  

 

[soviet_merlin]

46 minutes ago, Duncan said:

Right, so while continuing to avoid the stalling issue, I decided to fix the clunk under acceleration by changing the diff bushes. Of course, it turned out not to be the diff bushes, they were in pretty good condition, but by the time I got there, there was no point turning back without doing the job.

What kind of clunk is it? I have it occasionally where it clunks once in the back of the car when going from clutch disengaged to engaged and driving. Doesn't happen often though so I'm not too worried / annoyed at this point.

Appreciate you sharing the process! Especially the little things that go wrong.

So you haven't worked out what it actually is yet, right?

[Dose Pipe Sutututu]

On 25/04/2023 at 8:13 PM, Duncan said:

Still don't know why the car is stalling (although I have a hint now, looks like ECU is turning down the injector duty cycle until it stalls).

Look at your O2 correction long term and short term trim tables to see if there are any weird values in there.

Then look at your real time trimming at idle, could be a dodgy wideband O2 sensor sending back wrong valves causing your ECU to think it's running too rich and pulling out fuel.

[Duncan]

1 hour ago, soviet_merlin said:

What kind of clunk is it? I have it occasionally where it clunks once in the back of the car when going from clutch disengaged to engaged and driving. Doesn't happen often though so I'm not too worried / annoyed at this point.

Appreciate you sharing the process! Especially the little things that go wrong.

So you haven't worked out what it actually is yet, right?

Well, I haven't really taken it for a drive yet, I was 99% sure it was diff clunking, it happens when you moved away from a standstill under power (sounds pretty much like yours). Poking around with a pry bar in the suspension arms didn't give anything away but again that is much easier on a hoist. It is not terrible but still, I'd rather everything was 100%

I think I will repeat my mistake and next replace the gearbox and engine mounts. Even if they are not the problem, the car needs a little love after so many klm....

[Duncan]

1 hour ago, Dose Pipe Sutututu said:

Look at your O2 correction long term and short term trim tables to see if there are any weird values in there.

Then look at your real time trimming at idle, could be a dodgy wideband O2 sensor sending back wrong valves causing your ECU to think it's running too rich and pulling out fuel.

Thanks mate. I haven't really explained here because I haven't made great progress on this, plus internet troubleshooting without much data is a tough call

It is an intermittent stall. Has happened at idle, when driving and when going to start it, in each case it seems it is not getting fuel into the cylinder.  At other times, it starts, idles, runs OK but I haven't been brave enough to take it far since I've had to flat tow it back twice now

Following the "everything is pretty tired by now" theory, I replaced the fuel pump, fuel filter, injectors and fuel pressure regulator, all to no avail (at least I have spares now). I also cleaned out the tank and replaced the fuel pump sock which was the only suspicious looking thing, but still an issue.

[Duncan]

But, let's give it a try. This is a shot of a data log of about 15min of trying to find and fix the problem:

The car started with throttle around 9min, then suddenly started idling happily at 10:20 until about 16min with no obvious change to anything, other than the MAP went from around 7 to about 5. At that point it idles and runs OK.

At 16min I started poking cooler pipes due to suspicion of a leak and it stalled but I'm not concerned about that.

This is the target AFR map around idle

I was surprised the target for idle is 13.67 not 14.7 and did some testing with the 4 highlighted cells. When it was running it made no real difference between the original and my change, not sure why it was set that way by the shop; I'll ask sometime but I don't think that is the issue

The other thing I fiddled was that it would not start or idle on the original fuel map, but when I tripled the fuel as a test at lower MAP levels it started and ran fine:

So, the symptom seems to be that when the MAP is reading below about 7 at idle or when cranking, it won't run on the original map. The question I haven't worked out the root cause of why the MAP at idle varies so much, faulty sensor, leak in the MAP hose (wouldn't that increase MAP, not decrease), intake leak (same, wouldn't that increase MAP)???

[Dose Pipe Sutututu]

Please send me the log 🙂

I'll go through it during work hours.

 

Also your richer than stoich idle target is probably due to your injectors inability to work at such low pulse widths. I'm going to assume they're not modern stainless injectors?

[Duncan]

Thanks for the offer, will do. Injectors are Xspurt 1000

[soviet_merlin]

On 07/05/2023 at 10:48 AM, Duncan said:

Well, I haven't really taken it for a drive yet, I was 99% sure it was diff clunking, it happens when you moved away from a standstill under power (sounds pretty much like yours).

I think I will repeat my mistake and next replace the gearbox and engine mounts. Even if they are not the problem, the car needs a little love after so many klm....

Yes that sounds about right. Looking forward to see how it works out for you. Sounds like a bit of a bitch of a job to get done so I'm not looking forward to it.

 

Hah, I read that as you going to replace the gearbox. I always wonder what they are like to drive new. Though I doubt it'll somehow turn it into some Ferrari gated shifter experience.

[Duncan]

ahh yes I didn't say that very well.

funnily enough, I did purchase the box in the Stagea brand new in a nissan box, although it went straight to Award to get upgraded then into the race car for about 10 years, so it is a long time past it's prime. Back in the day second hand boxes were about 800 and brand new 1500 but the synchro/clips etc upgrades cost 1-2k anyway, so might as well start with a good platform.

[Duncan]

So, since I still haven't found a smoking gun for the stalling I did a more complete boost leak test.

I have one of these Raceworks boost leak testers (incidentally, if they are going to copy our race team's name they could at least give me freebies). I put it into the cooler piping at the turbo outlet

 

Blocking off the other end not so simple. I've still go the the 64mm intake piping from the first time the front mount was installed (which might be a little small for the current setup), and I had an 64-50mm silicone reducer and a 50mm rubber cap, so I used those with some spare GTR BOV return piping to block off the cooler piping just before the throttle. I also had to block off the hose from the intake to the AAC.

Ran it up to 15psi with a tyre inflator (the boost tester has a Schrader valve which is good for regulating test pressure) and it immediately started leaking back down. checked all the joints with soapy water and I found a very obvious and pretty large leak

https://www.hgeconsulting.com.au/boost-leak4.mp4

When I turned the clamp on the pipe the leak followed it so I replaced the clamp. Incidentally, these T style clamps are basically overpriced junk; just use a good quality 8mm hose clamp up against the lip at the end of the intake pipe . Later inspection showed the clamp was bent under the screw iteself, no wonder it was leaking and probably had been since the day it was first installed

There was another, smaller leak from the intake air temp sensor, I'm pretending that doesn't exist for now

https://www.hgeconsulting.com.au/boost-leak5.mp4

After fixing that the car was idling properly for a while, but they seemed pretty minor leaks to me and the car is running a MAP not AFM so I expect it to tolerate intake leaks to some extent. I'll take it for a proper drive but no reason to think the underlying issue is fixed.

 

 

 

[Duncan]

The other thing I did some work on was the Dayz side skirts.  They make the car look much nicer (my opinion) than without in a 90s kind of way, but they are held on with a crappy combination of bent sheet metal brackets and plastic clips.

Over the years anything that hits them (plus time) causes the clips to break and they don't sit properly. Many years ago someone found and posted up the part number for the factory clips and I should have got them at the time, they are no longer available.

Anyway, I removed and straightened the brackets as best I could, tightened the self tappers that unknown animals had used in a few places to hold it back on, and replaced all the broken factory clips with standard trim clips (got these aftermarket from here https://www.carpartsclipsandfasteners.com.au/product_info.php/nissan-infiniti-door-card-trim-clips-p-525)

They were very tight in the thick plastic of the side skirt and also in the hole in the car, but they are holding OK for now....will see how they go over time with rough roads etc

Neil suggested more than once that I should use wing nuts on the GTR engine mounts for ease of replacing blown engines, but I never expected to come across a wing nut from the nissan factory.

Well, there they are, 2 wing nuts are used inside the front guard to mount the front of the side skirts

Incidentally, I know my car is high klm and does a lot of off road work, but please all Stagea owners check inside the bottom of your front guards for build up of crap. You can kind of see in the pic that the rear edge of the front guard is not sealed at the door (pic was taken from the wheel arch where there is a plastic cover normally). 

This is what I removed from one side of my car (other side was similar)

[Duncan]

My current theory is that I have a failing or mis calibrated onboard MAP sensor as the ECU switches between running perfectly and running like a bastard for no obvious reason other than the MAP being much lower when it does not idle (eg -9 psi vs -4 psi MAP)

So, I googled "normal MAP at idle".

Congrats to the AI troll factory for getting this word soup so far up the google results, it is definitely worth a read if you are interested in vacuum pressure and potential stroke causes in one handy location - https://www.cushyfamily.com/what-should-map-sensor-read-at-idle/

[soviet_merlin]

Haha! I'll make sure to have my GP check my intake manifold pressure next time. Thanks Dr. Internet!

[joshuaho96]

2 hours ago, Duncan said:

My current theory is that I have a failing or mis calibrated onboard MAP sensor as the ECU switches between running perfectly and running like a bastard for no obvious reason other than the MAP being much lower when it does not idle (eg -9 psi vs -4 psi MAP)

So, I googled "normal MAP at idle".

Congrats to the AI troll factory for getting this word soup so far up the google results, it is definitely worth a read if you are interested in vacuum pressure and potential stroke causes in one handy location - https://www.cushyfamily.com/what-should-map-sensor-read-at-idle/

-4 psi sounds low for idle no? I'm used to seeing something like -9 psi. Obviously snapping the throttle shut coasting at 3000 RPM will pull it pretty close to full vacuum.

[GTSBoy]

1 hour ago, joshuaho96 said:

-4 psi sounds low for idle no? I'm used to seeing something like -9 psi. Obviously snapping the throttle shut coasting at 3000 RPM will pull it pretty close to full vacuum.

Yes, that's the point. -4 is obviously a problem when -9 is expected/typical and previously seen on the same car.

[Duncan]

right-o, well happily that problem with starting/running is solved. It was indeed a MAP sensor issue of some sort.

I had got to the point of total desperation where I actually opened the manual. Right there on p 13 under "MAP Sensor Calibration" it stated there is an onboard barometric absolute pressure sensor (BAP) and that with the key on and engine not running that MAP and BAP should be the same. 

And yet...

MAP and BAP are totally different. In fact, when I tried to calibrate the MAP sensor through the menu, it said: 

Which is actually a good thing, because had I been able to calibrate the dodgy sensor I might have stopped looking there and just blown up the engine instead.

It's not yet clear if it was wiring, boost source or sensor, but when I physically moved the MAP sensor it started working properly, and the car is running like nothing was ever wrong. 

It is running the Link 4 bar sensor so I've grabbed a spare and will swap it in if the problem recurs.

[Duncan]

Now that is sorted I can decide between trying to get the Fuga hybrid started (EV system error) or work out why the LHD swapped Titan is stuck on full hot for the cabin heater. I suspect neither are simple either.