I'm mildly curious if you have a Turbo boost/pressure sensor and if it's getting vacuum/pressure from the intake manifold.

 

Yes. It was mid-70s and humid here in Austin tonight.

Fuel pump is a brand new Walbro.

The SAFC-Neo has not been touched except for the initial configuration so should be pure pass thru. I'll unplug it tomorrow to take it completely out of the loop.

 

Thinking about it a little more, the guide I had for installing the SAFC said that when he touched his TPS, he had to reset the SAFC. I didnt think about that because I never set anything besides the arrow direction and the cylinders so I assumed it wouldnt be doing anything.

Maybe it was confused because of the old TPSs. On the other hand, since in theory it should have just been doing a pass thru, it shouldnt matter.

 

yes, at your recommendation I got the Z one. The readout is in the 4th row. I tee'd it into the N374 Boost Pressure feed line.

 

I remember being in closed loop under part throttle low boost when I had stock ECU/Rtek 1.7 (s4 car). It was a couple years ago and it's kind of fuzzy now, but I do remember being surprised about it. I wonder what determines the closed loop threshold on the factory ECU. It has to be some combination of throttle position, MAP, and/or AFM reading.

 

I meant the stock boost sensor. Sure it's a Turbo one?

Also I'm thinking the fuel pump resistor relay up front. Maybe its stuck in the low voltage mode? Fuel pump only seeing approx 9vdc instead of going to full alt voltage during load????????????

I watched the closed loop on my 86na car last night. It won't stay in closed loop under load, for what that's worth. I mean you will be in a constant closed loop and then step on the pedal and it immediatley goes out of closed loop. From the 14.7 range immediatley to the 13's.

That chattering boost solenoid makes me think there's a problem with the boost/pressure sensor. I'd put the USER 1 on the boost sensors input wire at the ECU and go for a ride and see what's happening there. Guessing, but don't like chattering relays/solenoids.

 

ah. Ok. Yes, I bought tii AFM and boost sensors from Japan2LA. It's possible that somehow I inadvertantly put the na one back on but that's easy enough to check. I'd tested it per the FSM and it checked out fine.

We have the boost sensor readouts in User1 in the Zeitronix data files I posted a few weeks back. So we can see that.

I don't know if the duty solenoid is still going to buzz. I noticed that after replacing the TPS that the whoosing noise I would hear while accelerating went away. I thought it was the turbo because it sounded a lot like my wifes Audi A4 2.0 turbo. I now think it was the acv dumping air. And since the TPS was replaced our AFRs are no longer nonsensical.

 

Your still wondering about the humps in the afr in the jpg a couple of posts above. The one where your boosting and the afr is in the 14's and the humps look similar to closed loop.

If right, then I suggest pulline the 02 wire off the sensor and repeat the same typr driving cycle to see if they go away. I really don't think you can go closed loop while boosting/accelerating. It's too lean imho when your boosting 3-4 psi and the afr is 14.7 . It's just not natural. Well at least to me it isn't.

The zeit graph I posted a few post above was on a car running half E85 and half regular, and frankly the fuel was adjusted up 22.5% and nothing more after doiing that. It has some small 14 spikes under boost in there.

 

I pulled the O2 plug and it did not change anything. It still humps.

I looked at the JDM harness and lo and behold there is a N370 boost sensor. Of course, like the reverse switch and the nipple on the purge control valve the importer broke off the vacuum nipple. So I took a drip irrigation head and ground it out then epoxied it to the boost sensor.

So we'll give that a shot. If there is no change, then I think we're sure it isn't the boost pressure sensor.

While the epoxy cures, I'll read up on how to test the fuel pump relay. Given that it smooths out real nice past 4k up to 5.5k - which by definition should be consuming more fuel than at 3k - it would seem that the fuel pump is supplying the necessary pressure and fuel. But I'll understand the fuel system better after reading chapter 4.

Your latest note HAILERS makes me wonder if I should just use the SAFC and richen it up from 3-4k. RTek doesn't pretune for the porting and free flowing exhaust I have and Rob at Pineapple said I'd need the AFC to keep it from leaning out just with the porting in particular going up hills. Plus the RTek is tuned for 720s in the secondaries and I have 1000s which should make us 25% rich.

Oh, and the duty solenoid isnt chattering anymore. I think the TPS was freaking it out like it was the ACV.

Thanks,

 

I am claiming gloating rights about the TPS.

 

Granted!

Now, if you can remember the details of your humping problem... :-)

 

No change with the JDM N370 pressure sensor. I'm going to richen it up.

 

Ok, richening it up in the 2500-4000 range seemed to work. I used the SAFC to bump up the AFM value by 18% (ramped at beginning and end). The surging went away and here is what the Zeitronix showed...



Drove beautifully on the way back from the empty road we used to test. Of course, now it wont start. I'll bypass the SAFC and see if that allows it to start again. I set the lo to 30% and the high to 80%.

This is like playing Jenga!

 

Oh, and just to confirm, my boost consistently caps at 5psi which would indicate the wastegate, duty solenoid and related plumbing are all good, right?

 

shouldn't it be higher than that on an s5 with the factory boost control solenoid? my s5 turbo on an s4 car ran 6psi with no boost controller

 

I have no idea. I know Ive seen 5 thrown around a lot. I may have to go and see what the FSM has for validation/diagnostics on it. I flattens right out at 5 though so I dont think that is accidental. Something wants it there.

I'm going to keep my eye on it. At 5 I think it will be fine for our break-in period so not an urgent area of focus.

My wife and I took it out tonight and cruised to the grocery store with the top down. But tomorrow we'll be down to the 40s from the high 70's. So I guess we'll get to watch for creep with all that cold, dense air.

I'm beginning to wonder if I went too small with the 720s on the primaries. I think that between the Pineapple ports and the exhaust, we're flowing more than RTek intended with the 1.8.

I think we need more richening pretty much across the board which leads me to wonder how much duty cycle is left in the 720s.

 

On stock turbo there is no way you will run out of fuel with 720/720. not a chance. my car did 250rwhp on 550/720, big street port, s5 turbo at 13psi. you aren't going to make much more than that. You can do 300whp with 720/720

Have you rewired the fuel pump? You have made no mention of doing so. It makes a HUGE difference. I noticed it especially when I had my 720/1680 setup. My injectors were at like 85% duty cycle at only 13psi (T04S turbo) and wouldn't richen up. Once I rewired the fuel pump, bypassing the resistor relay completely (something you could do if you reset your idle mixture with the variable resistor), my WOT duty cycles were around 70% at that boost level.

 

No, I havent done the fuel pump rewiring. I've seen references to it but havent paid any attention. I was assuming that I was going to be fighting rich so havent really done the research on that. Plus I thought it was for people with badly corroded wiring or those going for monster HP.

In the 3-4k range we're bumping the SAFC to +18%. I assume you can only see injector duty cycles with standalones but if you say I dont have to worry about it then I wont!

I'll do the research on it. If it is just forcing the fuel pump to run at 12v all the time instead of 9v I'd have to wonder why Mazda spent the money on the bi-level system. I woudnt want it to turn into the throttle body mode that repeatedly gets called out in the "worst mod" thread. I'll have to find a write-up.

I have an S5 so I dont think I have the variable resistor. That's an S4 only deal, right?

Thanks, arghx.

 

I've never done much work on an s5, just driven one. Check the fuel and emissions section of the s5 FSM. If you have a turbo car, you need to rewire the fuel pump. You can also retain the resistor relay and relocate it, but that is a pain in the ***:

http://www.1300cc.com/howto/how2/rewire.htm

 

Thanks. I Googled rx7club.com and found your drawings.

 

Interesting. So the whole point of it is to move the resistor relay to the back so it is closer to the pump and then to run a dedicated line for pure, unadulterated power.

 

You can see duty cycles on a RTEK 2.0 or a digital meter with a Duty Cycle feature.

Some have seen the fuel pump relay resistor package fail to the resistor side of the outfit. Meaning constant low voltage to the pump.

If you suspect that might be the case, just back probe the fuel pumps elect connector and go for a ride. Low voltage under no load conditions and high when under load.

It's a output from the ECU to the relay/resistor that switches modes. Green/red wire. Controlled by the input of the boost sensor to the ECU.

 

I'm guessing that would be pin 1K.



They dont say it but I'm guessing that in addition to "idle" that the output also goes to 12V when the boost comes on? If I understand the operation, when you reach positive pressure (or some other trigger) via 2H, the ECU sends 12v out thru 1K which triggers the relay to shift the fuel pump from 9v to 12v.

A more direct measure of the system's performance would be to simply run some wire to the pump and read the voltage from the cab, right?