rb25det weird idle and WOT issues

[racebreads13]

ok guys first off this is what i have
series 2 rb25det
3.5" exhaust staight pipe built by me
fmic
freddy mani with q45tb
3" intake
power fc
walbro

ok so during WOT it seems like it holds back it spools great but it doesnt go through the rpm range smooth or powerfully (this is with the power fc and z32 mafs)

since it was running weird i put my stock ecu and stock mafs then it started idling at around 2400- 2700 rpm and would like stall or choke out when i tried leaving from a stop.

now i have the power fc back on and stock mafs and it still chokes out trying to move from a stop and it holds back under boost but idles fine around 900 rpm also after i turn it off for the night and start it it kinda sounds like an sti as if its missing i guess? but idles fine after 30 sec to a minute..

thanks for any help

[Krazykouki]

What is your fuel pressure looking like? Do you have an adjustable regulator on it? What is your air fuel doing at the time of the stall's?

Also, check your plugs and check the resistance on your coils. If your plugs are fine and your coils are fine, gap the plugs to around 30 and see if that helps.

My RB25 idled weird when I put a FMIC on the car. I upgraded to the Z32 MAF and tuned it with an SAFC2 and it started working correctly. Later down the road, it was doing something similar to what your talking about. It ended up being plugs.

[Darius]

The engine should idle normally with stock ECU, MAF, and injectors. FPR isn't necessary but you may need to verify that the stock FPR is able to maintain fuel pressure under boost.

Have you checked for boost leaks with a pressure tester?
Have you verified the ignition timing with a timing light?
What condition are the coil packs in?
Do you have a wideband O2 sensor?
Is the IACV screw turned all the way to the right, less 1/2 turn CCW?
Did you do the idle relearn procedure each time you changed MAF sensors in the PFC?
Did you change the MAF sensor setting each time you changed MAF sensors in the PFC?

[Krazykouki]

FPR isn't necessary but you may need to verify that the stock FPR is able to maintain fuel pressure under boost.

He has a Walbro, they make almost all Nissan swaps run funny as they always overrun the stock FPR. I know my car ran like it was using an on and off switch for power until I put a new adjustable regulator on it, then it ran great!

Initialize the SAFC unless you have had it tuned.

Go into the SAFC Settings and select the MAF type which will be hotwire. Set the value's to 2in and 4 out...then under the calibration, set it to 1in and 1out.

then see how the car runs

[Darius]

I ran a Denso Supra TT pump for 3 years with the stock FPR in place and didn't have any issues. I had some odd issues, replaced the FPR with a NISMO and there was no change. I didn't even have to re-tune it since I kept the baseline fuel pressure the same. Krazykouki, yours might have been faulty. The stock FPR is fine for most of the setups on this board.

He's running a PFC, not a SAFC so he will be able to select the MAF directly by name if he is using a Nissan MAF.

racebreads13 - answer the questions in my previous post and we will be able to help you out more efficiently.

[racebreads13]

The engine should idle normally with stock ECU, MAF, and injectors. FPR isn't necessary but you may need to verify that the stock FPR is able to maintain fuel pressure under boost.

Have you checked for boost leaks with a pressure tester?
Have you verified the ignition timing with a timing light?
What condition are the coil packs in?
Do you have a wideband O2 sensor?
Is the IACV screw turned all the way to the right, less 1/2 turn CCW?
Did you do the idle relearn procedure each time you changed MAF sensors in the PFC?
Did you change the MAF sensor setting each time you changed MAF sensors in the PFC?

i dont have a pessure tester but my boost and vac stay steady according to my gauge

no but i will if i can find a extra spark plug wire layin around i dont have the right timing light to use the white ign check wire.. i can check it on my pfc do u know what its supposed to read??

no wideband

i didnt mess with the ivac i simply took off the stock mani, cleaned, and installed on the freddy

yes i did the relearn

yes i changed the maf setting

[racebreads13]

so one other thing i'd like to add i have not started my car in awhile and i forgot about this issue but when i start it after it sits like over night or in this case which was worse since it sat longer... it misses and sounds kinda like an sti and usally it clears up in like 10 seconds or so and when i started it the other day after sitting for a couple weeks it took like 5-10 mins to clear up what do you think it could be?

[marshallpre1]

I had issues with break up at WOT when I first got my car. All it was was crappy plugs. I changed to NGKs and the problem is gone. It could be something as simple as that. Start with simple, easy steps...

[racebreads13]

I had issues with break up at WOT when I first got my car. All it was was crappy plugs. I changed to NGKs and the problem is gone. It could be something as simple as that. Start with simple, easy steps...

i changed them when i did the swap wit ngk's also

[l0nestar]

Silly questions;
How do your coilpacks look?
Test (ohm-out) your engine coolant temp sensor (it's in the FSM, requires an ohm-meter / multi-meter and hot / boiling water.)

I can assume you have no consult cable?

[racebreads13]

coil packs look good from what i can tell this is my first rb so couldn't say forsure...

will do i have almost every electrical tester lol

consult cable as in obd stuff? no. i have the hand controller for the PFC and i had the datalogit but i sold that..

[racebreads13]

so i took down some info i was getting on my pfc hand controller from the sensor check this was idling at 1100-1150rpm

ign timing 19* and goes up to 40ish* thru the rpm range (i retarded this a few degrees because i read the maps on pfc's are ment for japanese 101 fuel and i should do that)

mafs 1.3 volts

tps .41 volts

water temp sensor 1.24 volts

o2 sensor would jump at idle from .00- .78 volts

extm 5.00 volts

idk if these are normal