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Well my stock as a rock R33 pushed 144rw/kw then pushed 165rw/kw after a full turbo back 3" exhaust and considering i had bad misfiring coils and 95RON fuel on a 28 deg afternoon... I should be looking closer to the 170 - 175rw/kw now with the new coils, 98RON fuel and on a 10 deg morning...

But thats a very nice result Quinny... :D

Regards,

Sarkis

Thanks mate. I was thinking about 160rwkw, but I suppose that the lean mixtures will help a bit. I am not sure if the ECU has been played with, the rev limit is still set at 7000, apparently it is pretty common for re-tuned ECU's to have the rev limit bumped up.

I had a look through the Dyno thread, I saw that there is a few cars running 12.5 AFR to 12 at WOT, so I don't think it is dangerously lean, but I might get the fuel pressure checked anyway and get an SAFC to sort it all out. I don't think I will worry about the PFC, I don't think I will need it with the mods I have in mind.

I had my AFR's tuned to 11.8 with my Power Fc (R33 gts-t with tbe, pfc, fmic, pod etc..)

Before that it was more like 10's..

Cheers

Rob

Ps. Could it be the fuel pump on it's last legs? (justa thought)

Edited by Robo
I had my AFR's tuned to 11.8 with my Power Fc (R33 gts-t with tbe, pfc, fmic, pod etc..)

Before that it was more like 10's..

Cheers

Rob

Ps. Could it be the fuel pump on it's last legs? (justa thought)

I hope that the pump is not on its last legs. The car only has 73000 on the clock, and given the condition of the car and the way it runs, seems to be pretty close to genuine. Surely a fuel pump wouldn't cark it after 73000kms. I am kind of hoping that I am wrong about the AFR, it might have been 12s to 11s, but I need to get a hold of the graph to find out.

I got the dyno sheet from Sureflo showing the AFR on it. It doesn't look good. Starts at just below 13 at low revs, then down to 12.5, back up to 13, back down to 12.5..... That seems way too lean for a stocker. Not sure if it makes any difference but this was the 4th run on the dyno, and looking at the speed I would say it was done in 3rd.

post-27958-1153263209.jpg

having it run in 3rd wouldn't have made much difference to the power.

something else that might be work looking at is the afm. if that is dirty, or not working properly then that could be the cause of it leaning out. if the afm is dirty then it doesn't read the full amount of air going in so it doesn't put in as much fuel.

with those mods and no piggybacks you should be running really rich... the safc is usually needed to lean your mixtures out not richen them up... I would say your fuel pump is on its way out or something else is up... that tune is probably bordering on okay but if I was you I would want to find out why it is like that in the first place

with those mods and no piggybacks you should be running really rich... the safc is usually needed to lean your mixtures out not richen them up... I would say your fuel pump is on its way out or something else is up... that tune is probably bordering on okay but if I was you I would want to find out why it is like that in the first place

I am hoping it is just a fuel filter or something like that, the car will get a service pretty soon. I don't think that it is dangerously lean, but it definitely needs to be sorted.

Pretty sure stock computers run much richer then that. So as has already been said something fuel related is on the way out or your computer has somehow had a remap/different tune.

The power figure it self doesnt really mean that much, there are always so many variables. I think its only useful for before-after comparisons and tuning. The way I see it, if it feels fast its fast, not if its got a big spanking number on the dyno sheet.

Edited by Rolls

If that was my $16,000 investment, I would do the following during your service.

1.) New fuel filter

2.) Injectors cleaned/ flow tested, and fitted with the highest flowing one to above cylinder 6 then next on no. 5 etc.

3.) Remove AFM and clean it.

4.) New spark plugs

5.) Hard wire in your stock fuel pump so it gets fuel voltage constantly

6.) Nismo fuel pressure regulator

7.) SAFC and tune.

Cost:

$30 – Filter

$100?? – clean and refit injectors

$0 – AFM clean

$30 – NGK BCPR6ES-8 (if they don’t have the -8’s you can also use the -11’s but will have to re-gap them)

$30 – hard wire the pump

$150 – fuel pressure regulator direct fit to stock position

$200 – SAFC

$150 – Tune

Boost to 10 psi and you’d be pretty happy for a while and the car will be safe.

Oh – don’t think that the fuel pump will not die after 70,000kms..

They can go at anytime.

I’d say it would be more common at about 100,000kms but you can never tell.

My S14 had 116,000kms on it.

I drove all the way from Sydney to coffs harbour.

Not a single problem all the way there.

Stopped at the hotel, idled for a minute, turned the car off to unload and check in.

And that was it.

It did not start back up.

Pump just died once turned off and never came back.

So it’s not like the pump will always die slowly… it could just stop instantly like flicking a light switch.

I got the fuel pressure checked this morning, the pressure was between 35-40psi at idle (240-250kpa), which seems about right, considering all other Nissans are 245kpa.

So that would indicate that the pump and regulator are ok (I would think). I will change the fuel filter and clean the AFM today as well, but hopefully it is nothing serious.

Any other ideas? I suppose I can open the ECU and see if it has a standard chip in it...

Edited by Quinny

Here is a pic of the inside of the ECU, looks pretty stock to me.....

I took off the AFM and checked it, it was a little dirty, but nothing really. I took the wire gauze off the front of it because I read that it can be a restriction.

post-27958-1153370161.jpg

  • 1 month later...

You cannot check the fuel pressure at idle.... I'd be more than hapy to bet $10 the pump is ROOTED, do a run on the dyno and watch the fuel pressure as it comes on boost...

I have seen that curve so many times (except I back off before you hit that peak lean spot)

Invest in a Bosch 040 ($250 - $280 Fitted) as the pump is a known common problem, then re-dyno.

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