R33 Gts-t Randomly Turns Off, Bloody Annoying

[theforce]

Hi guys, First of all, I've researched this problem everywhere and followed advices, but none had fixed this problem.

I've got a 94 R33 GTS-T automatic. Only mod is a cat-back exhaust. Recently out of nowhere it turns off randomly. Sometimes it turns off after 30seconds when you start it. Other times when the car is warm in driving, it loses power and starts to choke until it turns off. It also sometimes turns off when you are on a small slope and you let go of the accelerator.

I've changed the fuel filter, air filter, spark plugs (BCPR6ES), haven't changed oil/oil filter yet. I've also checked the fuel pump and seems fine. I re-soldered my old Green Label AFM and that didn't help. The AFM made no difference to the engine note when engine was started with afm not plugged, and when afm was plugged back in and revved, it started to choke. I bought another 'tested' afm and test drove the car yesterday for 45 mins and it was all good.

But this morning after a short drive it turned off when the accelerator was released.

Also the previous owner may have had a Apexi AVCR or SAFC as I checked the ecu and it had wires tapped into it.

Any ideas or suggestions. Is this electrical problem? could something be loose? spark plug transistor? fuel pump relays?

[theforce]

I looked around and some people suggested to reset the ecu when afm is changed or cleaned/re-soldered. So I removed the ground from the battery to chasis and took the connector out of the ecu (removed the bolt). After about 45mins I plugged everything back in and the car hesitated to start for about 5mins. Then it turned on and after 5mins turned off. When I managed to get it on again, I took it for a drive. It would go over 45km/h and would choke and turn off if I accelerated even a tiny bit. Also alot of black smoke, prolly indication of running rich?

Then afm voltage is something like 0.08V when I check with the consult cable on my laptop. I'm thinking of removing any wire tapped into the ecu loom and checking the afm wiring as I found a pinout for the ecu. See if that works.

[RB25PWR]

Check coil packs?

[theforce]

Haven't checked coil packs yet. How do I go about doing that? remove one by one when engine is running and see how the engine behaves? or with a multimeter?

Also, since the car is stock, am I using the correct plugs for a stock car? I believe I put in BCPR6ES, which is pre-gapped at 0.8mm. I put these in after browsing these forums and people suggested that these behaved better than the 1.05 or 1.1mm gapped plugs and will suit the engine when/if boost was raised.

I pulled the ecu plug out and removed all the wire that were taped into it and re-soldered the original wiring. Battery ground was not plugged during this process, which took around 40minutes. I reconnected everything and car turned on first, although lumpy and choky at start, it slowly settled after I test drove it for 30minutes. Revs went all the way and no choking. Turned car off and then took it for another drive an hour later and it all seemed good.

I'm hoping the ecu re-set itself and is learning everything now, but will find out in the next few days.

Thanks RB25PWR, will keep posting what happens, hopefully nothing happens

[RB25PWR]

I'm far from even an internet mechanic... but if your car is turning off like that I'd be guessing it's an AFM issue? Probably also the ECU... Maybe someone else can shed some light on this as I'm a retard when it comes to mechanics but whenever I read about a car just turning off like that people seem to suggest that something is wrong with the AFM...

[Munkyb0y]

maybe the previous owner didnt do a good job of removing the avcr/safc? may be a wiring issue with the harness at the ecu.

[theforce]

Thanks for your reply guys. The ecu itself looks un-touched, its the wiring thats been spliced and the afm wire coming to the ecu was all over the place, cut/soldered/extended. So I fixed all that, no extra wires there now.

I turned it on this morning and it turned on first go, drove fine when I went round the block. The real test will be in the next few days when I drive it to work, which is like an hour in traffic as well.

Really frustrating when people screw around with these cars and don't let others know about it. Thats why I've changed everything back to stock in this car except for the led tail lights and cat-back .

Will post how it goes during the week.

[Panko]

Try cleaning the AFM with the CRC cleaner, start from something simple then work your way to something

a bit more complicate. Make sure no leak at your BOV as well.

Good luck !

[theforce]

Cheers Pan Will get some spray happening in there. Also, is WD40 bad, coz I sprayed my old afm with and it never dried!

How can I check for bov leak?

It drove fine to work today, but when I drove to get some lunch it turned off once and then turned on fine. Drove fine for the rest of the day. Only thing I noticed was that when idling, once every few minute it does a very slight jerk!!!, it is auto, not sure if that matters?

Also, my tacho is a bit slow , when I accelerate it starts slowly to creep up and when I let go, it slow coming down as well. Not sure what its doing, could it be just a faulty tacho in the dash? or is something causing it to do that?

Cheers guys, keep the suggestion coming

[theforce]

Alright, car drove all good today and I drove it another 50kms after fuel light flashed and then stayed on. Filled it with V_power, just managed 60L worth $85 , meh its all part of the game.

[JoelyMoley]

i put money on the AFM, don't use WD40 to clean it, use a stainless carby cleaner because it dries in seconds, unfortunately cleaning my AFM wasn't enough so i got another one of a forum member today, seems to be smooth sailing thus far! lets hope my fuel economy improves aye!

[theforce]

i put money on the AFM, don't use WD40 to clean it, use a stainless carby cleaner because it dries in seconds, unfortunately cleaning my AFM wasn't enough so i got another one of a forum member today, seems to be smooth sailing thus far! lets hope my fuel economy improves aye!

Hopefully that fixed your problem. AFMs are a pain to run, thats why my gtr uses a map sensor, no if, no buts, it just works. Never had a problem. Of course I never really paid attention to the fuel economy side of it