several rb questions

[bubzb20z]

my rb20 in my hatchs crank pulley is very bouncy. It causes the alt belt to squeal for a minute. Any ideas? Never really noticed it before, and I drive the car a lot.

My rb25det in my coupe came with a q45 maf. Im switching back to a z32 MAF. Will my safc2 tune be compromised. Im experiencing MAF problems were I cannot get it to idle at all, but runs flawlessy through all rpm with no issues.

Any ideas would be appreciated.

[Shocker]

oh dear.... crank pulley bouncy? is it rubber?

Tighten your alt belt..... should fix the squeal, or get a new belt them re tighten.

why are you switching mafs?

[Darius]

You might want to pull the RB20 crank pulley off and check the back of it. It is technically a harmonic damper and the rubber could be torn on the back of it limiting the damping that it is capable of. Definitely shouldn't be bouncing around on the crank (That's what she does OHHHHH!! High fives!)

For the MAF, if you have stock injectors and a stock ECU, you should really be running the stock MAF. However, if your tune is based around the Q45, the Z32 MAF is very similar through a majority of the rpm range and it shouldn't cause any major issues. The AFR will just be a little richer and you won't get the best performance. Up top, it will run richer.

[bubzb20z]

oh dear.... crank pulley bouncy? is it rubber?

Tighten your alt belt..... should fix the squeal, or get a new belt them re tighten.

why are you switching mafs?

I thought the q45 was overkill. Im at 12lbs, pt 60-1, and 351 whp. Very inconsistent running through the rpm. SAFC correction was bouncing all over the place. Plus I got the Power fc, and wanted to put on the z32 to get it to work easier. Power FC doesn't even fire up my car at all, and we chased down some Maf wiring problem at the ecu, but now I can't even get it to idle when a MAf (either one is hooked up) My ecu for the rb25 is stock and I can't pull codes off it, b/c it doesn't have an led light or dial, and I have an extra rb25 ecu with the diag setup, and it won't even fire my car either.

Crank pulley just has movement. It's more jittery. It has stg 3 clutch, and sometimes I can get get the belt to squeal, when I pop it frolm a standstill in 1st gear. Almost like crank walk or something

[Shocker]

Not being able to idle is a tuning issue get someone who is firmillar with the PFC to help you out, you should be able to use either MAF.

As far as the crank pulley, make sure its properly torqued down, it might be loose, it shouldn't wiggle at all!

[Darius]

The size of the MAF doesn't have anything to do with the issue. It is all in the calibration/tuning. With the PFC did you change the MAF settings to Q45 before trying to start it or did you just plug it in and try to fire it up?

[bubzb20z]

The size of the MAF doesn't have anything to do with the issue. It is all in the calibration/tuning. With the PFC did you change the MAF settings to Q45 before trying to start it or did you just plug it in and try to fire it up?

We changed the Maf settings and nothing. Then fooled around with injector latency, and got nothing but raw fuel smell. I was told the injectors were plus sized (rebuilt) stock 370 JECS injectors.

The SAFC settings show -50% at idle, -14% cruise, and -20% WOT

I only have one blue relay down near the ECU.

Im to the point where the whole harness is coming back out. Upon the MAF wiring plug correction, the white MAF wire from the harness connects to the black/grey on the plug. THe solid black to the white, and the white/black, to white/black.

[JPsNissans]

So you're running a bigger turbo and 351 whp with stock injectors.

[craz4240]

So you're running a bigger turbo and 351 whp with stock injectors.

Werd this is really weird....seems the tuner doesn't know what he's doing.The messed idle could be boost leak or vacum leak related.

Throw the SAFC2 in the garbage...like Carl H has said b4 it drives timing down the throat of your motor which can make it ping or grenade.

The crank pulley should not vibrate whatsoever....if it does it is not balanced and will reek havoc on your crank bearings.

Stock injectors whether resized or not should not be sufficient for 350whp,do you know your injector duty at this ower level and AFR's???

[Carl H]

this thread makes my head hurt...i dont understand why you need to pull fuel with a larger maf when the opposite should be true.sounds like you have some wiring issues and if its only got one blue relay its a s2 motor/harness and you might be trying to fire it up on a s1 ecu which wont happen.

[Red93coupe]

Hey Carl, I emailed you yesterday just wondering if you got it? Sorry for the thread jack...

[Darius]

I think what he was saying was that he was going from being tuned on the Q45 to the Z32, which will require less fuel for the same voltage readings.

[bubzb20z]

So you're running a bigger turbo and 351 whp with stock injectors.

Yep..PN of the purple jecs came back as 370. This car has gone through so many hands, and now im gonna get it right. But prev guy thinks they are 660, or 550, just rebuilt aparently to those specs. When the car is down, Im sending them off to RC find out for sure.

this thread makes my head hurt...i dont understand why you need to pull fuel with a larger maf when the opposite should be true.sounds like you have some wiring issues and if its only got one blue relay its a s2 motor/harness and you might be trying to fire it up on a s1 ecu which wont happen.

So is this why the Power FC I bought won't fire up my s2 harnessed rb25. I took the safc 2 out before trying power fc.Part #'s were the same for S1, and S2, but different for Neo right?

Thanks a bunch for everyones input. It is hard to find knowledgable sources as you all are. They are far and few beteeen here in KC, but there has been 1 very knowledgable source here to get me to this point, but I need to learn for myself too.

[Carl H]

perhaps the injectors were modified, if that was the case then they can potentialy flow 600+cc...but without pulling them and flowtesting you wont know for sure.as for the pfc not firing up the engine thats awfuly strange as the r33 pfc is the same for both s1 and s2 motors, i was refering to s1 and s2 stock ecus...you can use a s2 ecu on a s1 motor but not vice versa.

[bubzb20z]

perhaps the injectors were modified, if that was the case then they can potentialy flow 600+cc...but without pulling them and flowtesting you wont know for sure.as for the pfc not firing up the engine thats awfuly strange as the r33 pfc is the same for both s1 and s2 motors, i was refering to s1 and s2 stock ecus...you can use a s2 ecu on a s1 motor but not vice versa.

The whole skepticism on Q45 MAf downgrade was when I looked at the plug. They hacked an additional silver wire into the ground wire. The original copper black went to nowhere. But when joined in at the harness it went to the white.

Sorry for the confusion, but this is a sign of wiring faults other than at the MAF.

Here is a dyno chart. Power delivery was really wavy even when driving the car.

I bought it with a hole in # 6. Boost was set at 25lbs when I first put the good long block. It is now back at 12lbs, but cannot hold idle.