Nistune + wideband help

[Axt3365]

Recently done a bunch of upgrades to my 32 sedan and having some issues with the AFR. Was standard rb20det with just ISR exhaust, FMIC, and an op6 turbo until the seals decided they were done on the turbo. 
So I got a new gt2860rs, nistune (installed and tuned by rs enthalpy), deatschwerks 550’s, aeromotive fpr set at 45psi, walbro 255 , z32 maf, and aem UEGO.

Upon start up my wideband reads 14.7 but within 5-10 seconds will peg out to - - - meaning lean. I tried hooking the white wire (signal output) from AEM to the white wire on the o2 harness but it didn’t make a difference? I’ve also tried putting the sensor in the upstream (3” from hot side) and downstream (36” from hot side) positions with no luck on either? 

If it’s in the upstream position and under a lot of throttle it will richen SOME (16-17) but shouldn’t it be sitting around 13-15 at idle??? Have not tried driving the car yet to put it under load…

Am I missing something? Seems I’ve misplaced my old o2 sensor but should I just get another and resort back to narrowband to see if that fixes the AFR?

[robbo_rb180]

Have you set MAF to z32?
set injector size?

When I have used nistune, wideband is connected to the laptop via USB.
If can't connect to laptop put the sensor in the dump pipe bung and just adjust it reading off the guage.

@Dose Pipe Sutututu has more Nistune experience than me

[Dose Pipe Sutututu]

Depends on your AEM gauge, older ones has the option to simulate a 0-1V output which could be used to send back to your ECU for narrowband O2 feedback.

However needs to be noted, if the tune had the O2 feedback disabled wiring it back will do absolutely nothing. 

If your car is pegging that lean there may be another issue. You'll need to plug up and monitor the AFM voltage and TP Load and see if it's doing something weird and tracing into parts of a map that has been untuned.

I highly would recommend you bring it back to your tuner.

[Axt3365]

On 8/7/2022 at 9:40 PM, robbo_rb180 said:

Have you set MAF to z32?
set injector size?

When I have used nistune, wideband is connected to the laptop via USB.
If can't connect to laptop put the sensor in the dump pipe bung and just adjust it reading off the guage.

@Dose Pipe Sutututu has more Nistune experience than me

I sent Martin the list of parts I just mentioned for him to set the base tune parameters around that, including the wideband in place of the o2.

will need to find someone with a laptop and consult cable to check and see if that’s been done correctly. 

[Axt3365]

On 8/7/2022 at 10:17 PM, Dose Pipe Sutututu said:

Depends on your AEM gauge, older ones has the option to simulate a 0-1V output which could be used to send back to your ECU for narrowband O2 feedback.

However needs to be noted, if the tune had the O2 feedback disabled wiring it back will do absolutely nothing. 

If your car is pegging that lean there may be another issue. You'll need to plug up and monitor the AFM voltage and TP Load and see if it's doing something weird and tracing into parts of a map that has been untuned.

I highly would recommend you bring it back to your tuner.

I purchased the UEGO at the end of last year. The manual said white wire was 0-5v. I know the standard signal is >1v for these cars.

 

will have to find someone with a laptop and consult cable to check into the tune. Appreciate your quick replies. 
 

also it may be worth mentioning I have a standard fuel rail, one that came with a regulator on both sides. I replaced the one at the beginning of the rail with one of those ISR pass thru’s but left the one at the exit. Could this also be causing an issue or it’s unlikely to make a difference? 

Edited August 8, 2022 by Axt3365

[robbo_rb180]

where are you located?
Will need nistune tune software & licence to modify the tune.

[Axt3365]

On 8/8/2022 at 4:50 AM, robbo_rb180 said:

where are you located?
Will need nistune tune software & licence to modify the tune.

Lake Charles, LA, USA
near Texas on I-10

Edited August 8, 2022 by Axt3365

[Duncan]

On 08/08/2022 at 8:10 PM, Axt3365 said:

Lake Charles, LA, USA
near Texas on I-10

Dose will drop by in exchange for a passenger ride in something euro

[Axt3365]

On 8/8/2022 at 5:52 AM, Duncan said:

Dose will drop by in exchange for a passenger ride in something euro

That’s a negative ghost rider.

I’ve not got euro friends after an e46 expansion tank exploded in my face in a parked car. 

[GTSBoy]

On 8/8/2022 at 5:23 PM, Axt3365 said:

I replaced the one at the beginning of the rail with one of those ISR pass thru’s but left the one at the exit.

There's your problem. The stocker is not a reg, it is a pulsation dampener.

[Axt3365]

On 8/8/2022 at 6:03 AM, GTSBoy said:

There's your problem. The stocker is not a reg, it is a pulsation dampener.

Meaning it won’t let enough fuel pass through the rail despite what pressure is on feed side? 
 

just ordered another to replace the dampener and see if that makes a difference. Thanks! 

Edited August 8, 2022 by Axt3365

[GTSBoy]

On 8/8/2022 at 7:19 PM, Axt3365 said:

Meaning it won’t let enough fuel pass through the rail despite what pressure is on feed side? 

Yeah, there's every chance that it's an unnecessary restriction.

[Axt3365]

On 8/8/2022 at 6:34 AM, GTSBoy said:

Yeah, there's every chance that it's an unnecessary restriction.

Should have adapter in by this weekend. Hopefully that sorts it out! 

[Dose Pipe Sutututu]

Another thing that comes to mind, have you given the fuel pump full voltage and bypassed the stupid factory drop resistor?

Easiest way to just connect the pump's -ve from the fuel tank lid direct to chassis to bypass the FPCM/drop resistor.

Is your fuel pressure respecting the requested pressure + manifold pressure/vacuum?

[Axt3365]

On 8/8/2022 at 6:53 AM, Dose Pipe Sutututu said:

Another thing that comes to mind, have you given the fuel pump full voltage and bypassed the stupid factory drop resistor?

Easiest way to just connect the pump's -ve from the fuel tank lid direct to chassis to bypass the FPCM/drop resistor.

Is your fuel pressure respecting the requested pressure + manifold pressure/vacuum?

I have not bypassed it, just connected back as factory fuel pump was. I’ll try that this evening. 
 

the gauge on FPR is holding steady @ 45psi 

Edited August 8, 2022 by Axt3365

[Ben C34]

On 8/8/2022 at 9:49 PM, Axt3365 said:

gauge on FPR is holding steady @ 45psi 

That's before the injectors though isn't it. So not a useful measurement at all.

[Axt3365]

On 8/8/2022 at 8:04 AM, Ben C34 said:

That's before the injectors though isn't it. So not a useful measurement at all.

Correct 

[Dose Pipe Sutututu]

RBs are tough little things, to rule out any air leaks through the hot side, I suggest just take the car for a gentle drive and gentle load it up till close to 100kPA aka 0 psi for you Muricansssssss.

See if your AFR readings are somewhat richer than stoich.

I nearly feel you may have an small manifold leak somewhere OR a dump pipe leak somewhere that's introducing additional air into your exhaust stream thus the lean reading.

Anyhow, easiest way to diagnose all this is on a dyno.

[Axt3365]

On 8/8/2022 at 6:13 PM, Dose Pipe Sutututu said:

RBs are tough little things, to rule out any air leaks through the hot side, I suggest just take the car for a gentle drive and gentle load it up till close to 100kPA aka 0 psi for you Muricansssssss.

See if your AFR readings are somewhat richer than stoich.

I nearly feel you may have an small manifold leak somewhere OR a dump pipe leak somewhere that's introducing additional air into your exhaust stream thus the lean reading.

Anyhow, easiest way to diagnose all this is on a dyno.

I appreciate all your help and advice. I’ll finish tying up my loose ends, and get the car rolling around the neighborhood in the next few days and report back!

[Axt3365]

Update: after all that hassle, it was a faulty wideband sensor from it being placed too close to the turbo originally and cooked it.