Hunting, stalling and misfiring

[Aeoton]

Just wondering where I should look next to solve my problem. The car is fine cold, just when it gets to running temp does anything happen.

When idling, it hunts from 900/1000rpm to 200rpm. While cruising I lose power in 2 second intervals making it feel like I am tapping the gas. and when I push the clutch in to downshift or stop at a light the idle drops immediately and I stall. Yesterday as I was pulling away from a light my car misfired for a good 3 seconds

I've done a few things to try and fix the problem but none of them seem to have done anything.

So far I have:
Cleaned MAFs (In my trunk I found another MAF with a broken mesh screen)
Changed fuel filter
Checked coil packs
spark plugs
injectors
TPS voltage was good closed, open was 4.0
There are no thrown fault codes either

ANY help as to where to look next would be greatly appreciated.

[caliber676]

Wiggle or tap the maf sensor while running. If any of those symptoms occur while doing so you got yourself a maf issue. Cleaning the maf is not an end all to a faulty maf and that sounds like your problem

[GTRSOAR]

Wow thats idedntical to my problems. Especially with the car running fine when cold yet major hunting when warm. If I didnt shift quick enough it would stall haha.

My problem was (Also because I went single throttle body) that my TPS sensor wasnt set quite right so my car was constantly switching between my idle map and my 'driving' map. Sorry if im screwing up terms here. Id persure your TPS too. How stock is the motor? Any work done to the ITB's?

[Skym]

When on idle contact inside TPS it makes ECU switch to kick down tables that kicks rpm up to prevent rpm dropping below idle rpm and engine stalling. It also should switch to idle stabilisation tables when car is not moving.

The problem is the idle, WOT contacts (1x pieces of thin metal on each end of curved track on circuit board inside TPS) bends over time, so the idle, WOT contact's are not in the same place they were when TPS is new. Also the curved track on circuit board wears out giving incorrect voltage. TPS is a use, dispose of type of sensor that is checked, replaced around same time as o2 sensor (40,000km?-60,000km). If want to eliminate TPS, it requires a fly by wire setup (Motec M600 + small aftermarket TPS type of sensor that fits on throttlebody).

TPS can cause hesitation, engine randomly stalling, just to name a few symtoms.

Also replace o2 sensors (most people forget that they need to be replaced and is quite common failure on RB engines).

The hunting at idle can be due to o2 sensor making ECU run engine lean (revs rise) and rich (revs drop). When o2 sensor fails it becomes very lazy to switch between lean, rich and rich. lean. The result is engine pops flames from exhaust (popping sound from exhaust) due to running too rich for too long.

Also misadjusted atmosphere vented BOV can cause similar symtoms, as it affect's MAF (reversion or basically air reversing direction and making MAF measure more air than it should) thus makes engine run richer and stall (when combined with removing air behind MAF, as ECU has no way to know air has been removed behind MAF). Some move MAF further away from front of turbo's which helps to solve this reversion problem.

[Aeoton]

I appreciate all of the help! Haven't been able to get to a computer for a while but the problem is fixed now. The problem was something so stupid I don't even believe it... Even after resoldering the mafs and swapping out o2 sensors and tps for known working ones nothing seemed to help.

I went back in to take a second look for anything I missed and the problem was the maf plastic connector, I have aftermarket air intake and one of the brackets was mounted incorrectly and the plastic connection was getting bounced and slowly disconnecting. The locking clip on that one connection was broken so I pushed in back in and just zip tied it down. After that all problems ceased and the car is running perfect.