Rough Idle, Stalling And Shiz Fuel Eco

[graphyt]

Hey guys,

noobie to the boards but have had this car for a while.

Hoping that I can get some assistance because im getting a little overwhelmed!

The car:

Stock R33 GTS-T S1 - Automatic. not even a pod filter or FMIC.

The symptoms:

had the battery disconnected for a few days, plugged it back in started the car. Idles beautifully for a while 2-3 seconds then goes rough.

If I put my foot down it has a huge rev drop and will often stall. If it doesn't stall it will very slowly rev out and has no power at all. If it stalls, the car will turn over but not start. If i reset the ECU (battery fof and pump the brake) then it will start again, but with the same issues.

I get maybe 160kms per tank.

The ECU throws out no error codes. (ECU was checked before the initial battery disconnection)

also seems to be some potent fumes coming from the exhaust.

What I've done so far:

replaced AFM

replaced 1.1mm gapped plugs with 0.8 platinums

replaced coil packs with Splitfires (was getting massive arcing issues and these work amazingly!)

replaced fuel filter

ensured all intake hoses are sealed nicely

I'm thinking that this issue could largly be attributed to by the O2 sensor as I'm pretty sure it's never been changed. just waiting for the socket to arrive to change it over.

Has anyone else got any ideas on where else I should be looking? injectors? fuel pump? CAS?

any assistance will be greatly appreciated!

-Adam

[Spurdo]

checked for vacuum leaks? sounds like you may have a biggie

[mad082]

if you want to rule out the o2 sensor then just unplug it. in all honesty, the o2 sensor does bugger all when it comes to issues like this. it sounds more like you have a fuel issue. as jonboy said, look for vaccum leaks as that will make it run mega rich. i bet that if you pull out a sparkplug it will show signs of running super rich

[graphyt]

anything I should be looking for specifically for vaccum leaks? just took off most of the intake and put it back together and made sure all the hose clamps were nice and tight. can't hear any obvious hissing either.

should have mentioned, already tried unplugging the O2 sensor. no difference at all. also should have mentioned that i did the O2 ECU test and it's running rich.

[Dobz]

Water temp sensor?

[Moodles2]

Clean out AAC if you haven't done so already. Check fuel pressure, might be problem with pump.

[mad082]

anything I should be looking for specifically for vaccum leaks? just took off most of the intake and put it back together and made sure all the hose clamps were nice and tight. can't hear any obvious hissing either.

should have mentioned, already tried unplugging the O2 sensor. no difference at all. also should have mentioned that i did the O2 ECU test and it's running rich.

most likely it is running rich because of the issue you have, not because of the o2 sensor. the issue is probably causing the car to run too rich for the ecu to use the o2 sensor to lean it out

[blind_elk]

If it is stock and you have new Splitfires, then reset the plug gaps out to 1.1mm (certainly don't close them down to less than 1mm). Are you sure you have the right heat range plugs - RB25s use a 5, eg BKR5E.

Have you cleaned the injectors - not just run injector cleaner, but remove and sonic clean?

Clean air filter?

Check ignition timing.

[graphyt]

think I may have found the problem.......

ran it for about 5 minutes. checked oil cap. thin layer of cream coloured shiz. also running low on compression for cyclinders 1 & 2. looks like fun times ahead!

Just hope it's only the gasket and not the head.

[mad082]

most likely be the gasket, but you will need the head machined either way. cheaper than a new head though.

[Michael's R33]

have you messed around with the radio antenna lately?