Random Stall

[045HOW]

Hey guys my new car(1993 4 door R33 GTS25T/M) came with a pfc that was tuned prior to the previous owner installing a front facing plenum. When i bought the car there was a random stall whenever the car felt like it. usually on idle due to not driving it because when i bought it, it needed all new fluids and filters and the likes. At first when we took it out a few weeks back, if we hit boost it felt like the front of the car had been hit with a sledge hammer. Did some research and replaced both relays in the kick panel and 1 relay in the boot to sort out an obvious fuel pump problem. Upon doing this it was boosting fine, but still not much use as it wasnt registered yet. Now it is registered and randomly while driving the car will just cease to make power with throttle open, so i obviously take my foot off instantly and the revs will either drop and stall or drop,recover then drop and stall. If i try and start the car again after its stalled, it will not hold idle and just stall again but if i turn everything off and then on again it will start normal and idle normal.Switched fuel pumps with the spare pump from my old 4 door which certainly made some difference in how it sounded and much less shenanigans going on. but alas it is still happening. I am driving around completely off boost as the knock readings are not handy if boosted. Tune is almost certain for Saturday(will find out for sure on tuesday).

Settings in the PFC cannot be saved as once i turn it off any changes are lost, so i will be getting the wiring checked out during the week as per Paulr33s diagram and advice (cheers mate )

Timing is spot on,02 sensor is good,brand new fuel filter,brand new air filter,Stock injectors Reco'd and flow tested,fuel pump replaced,relays replaced,AFM cleaned,Splitfire coilpacks and new plugs.

Car has a HKS SSQV atmo BOV of which i noticed an extra high pulse of knock when it vents. Plugged up the vacuum line and am seeing much less knock within vaccuum and moreso stable knock if i hit any positive charge.

I have a plumb back nipple from the previous owner that i will look into installing this week as i know the perils/legalities/annoyances of having an atmo BOV with an AFM.

If i get my tune before i set up a plumback setup, which will be better to utilize during the tune? Dose or atmo? or does it not matter?

Thanks in advance for any help.

[SargeRX8]

In before The Mafia gives you shit about dose or vented. I'd put the stock bov on and block it with a coke. It looks stock but you get flutter! Your issues may be consistent with the bov. Also the f**king sound these hks things make could be hard as knock. I really doubt you're knocking when coming off boost.

Afaik, the power fc stores tune data in ROM, so it makes no difference if you lose power or not. Some changes you make using the hand controller are also only temporary... Why not reset your power fc, let it learn idle and see how it goes? You're going for a tune so you should be alright on the standard map off boost. Don't ever boost on the stock map, I guarantee big detonation. The fueling isn't too bad but it's got alot of timing where it shouldn't.

If you get a tune with flutter or atmo bov, you can't change your mind later. The tune from the blocked bov may also be different to an atmo suited tune.

Edited January 8, 2012 by SargeRX8

[045HOW]

In before The Mafia gives you shit about dose or vented. I'd put the stock bov on and block it with a coke. It looks stock but you get flutter! Your issues may be consistent with the bov. Also the f**king sound these hks things make could be hard as knock. I really doubt you're knocking when coming off boost.

Afaik, the power fc stores tune data in ROM, so it makes no difference if you lose power or not. Some changes you make using the hand controller are also only temporary... Why not reset your power fc, let it learn idle and see how it goes? You're going for a tune so you should be alright on the standard map off boost. Don't ever boost on the stock map, I guarantee big detonation. The fueling isn't too bad but it's got alot of timing where it shouldn't.

If you get a tune with flutter or atmo bov, you can't change your mind later. The tune from the blocked bov may also be different to an atmo suited tune.

I am also inb4 the mafia lol. I dont have a stock BOV but i have a front facing plenum so there goes the stock look idea anyway.

Atmo f**ks with your AFM. of course it can affect it.

None of the settings save like timing or injectors. If its not wired in properly apparently it wont save on power off which would be the case here.

As far as i can tell, there is no "atmo suited tune" when dealing with AFMs anyway.

[SargeRX8]

I am also inb4 the mafia lol. I dont have a stock BOV but i have a front facing plenum so there goes the stock look idea anyway.

Atmo f**ks with your AFM. of course it can affect it.

None of the settings save like timing or injectors. If its not wired in properly apparently it wont save on power off which would be the case here.

As far as i can tell, there is no "atmo suited tune" when dealing with AFMs anyway.

Put your afm between the throttle body and the bov then get your tune.

[045HOW]

Any idea anyone?