Problems With My Car

[Line]

Hi,

First this is an intermittent problem.

I only first experienced this today. I stopped at the lights and the car started idling very roughly.

I took off and it would barely accelerate, seemed to be once I got around 1,500-2,000 revs.

It's difficult to explain but it would not rev any higher than 2,000 and kind of makes a missing sound and reving up and down...

I rolled off the road, tried to rev it in neutral..still the same. I turned the car off, started it again was still the same.

I waited about 2 minutes and tried again, it worked fine this time.

I parked the car for about 1 hour, went for a drive. It was fine for about 10 minutes then started with this issue again.

This time when I pulled over..it would not rev past 1,000 even with foot to the floor.

I turned it off started again, drove to where I was going and parked for about an hour. Started up fine again, now I drove the car for about 3 hours on and off. No problems at all. After I stopped again, left it for 30 minutes. Driving again, after 15mins same issue.

This time when I let my foot off the accelerator, the car stalled. I started it again, the problem still persisted.

Turned it off for 1 minute, I drove home. around 10mins. It was fine all the way.

I've noticed when it starts doing this...on idle it will rev higher than normal and sometimes it will rev up and down on idle. Sometimes up to about 1,500 to back down to almost a stall then back up. It usually revs at about 900 when its running properly.

It's really intermittent though. I thought it might have something to do with the fuel but I've really got no idea what it could be.

Also it has another issue on idle which is extremely intermittent. It might happen once every 2 weeks.

Sometimes when I start it, it will idle abit roughly and stall right away. Sometimes this happens when I've been driving for a while and come to a stop. I was planning to get my mechanic to take a look at it on next service. I didn't worry too much because it doesn't happen often.

The thing is when it's not having the issue, it runs perfectly...

If anyone has any ideas of what possibly could be causing this, that would be great.

Thanks in advance

[R34GT-t_07]

i am going to take a stab in the dark and say that its ur throthll boddy..

Edited December 24, 2007 by R34GT-t_07

[zebra]

Id Say AFM's Or Igniter.

What Has Been Done To The Car?

[Line]

  zebra said:

Id Say AFM's Or Igniter.

What Has Been Done To The Car?

The car is stock standard apart from the exhaust and pod filters.

[Skyrin3]

There are a few things you should check,

1: AAC valve, this controls your idle when the throttle body is closed its location is on the back drivers side of the engine "Blue and Brown" plugs, i see you have an r33 so this is where u will find it. Take it off the car and clean it with carby cleaner. Do a proper job and get all of the baked in shit off.

2: Your Throttle body is full of crap, also clean that with carby cleaner.

3: Once you have done these, Disconnect your battery (If u have a stock ecu) and stand on the brake for about 1 minute reconnect the battery and go for a thrash and i mean a thrash, dont baby it or the ecu will learn a dodgy map. Your idle should return to normal.

If not let me know.

One other thing, Your TPS (Throttle Position Sensor) might be rooted, Hence the wont rev over 2k rpm. Its happend to people before.

[brother_david]

Could be the Lambda.. ¿ Drove a R33 GTR about same mods as yours, and it seemed to act the same way. Maybe you could borrow lambdas from someone just to narrow down that that isnt the problem.

[Line]

I've had the car for about 2 months and this happened first time today, otherwise it's been very good.

But I will try what you guys suggested.

Thanks so much for your help

[benm]

Remove both your AFM's, clean them out (leave the mesh + wire intact) and spray contact cleaner in the plugs etc.

I'd say you have a fault AFM.

[Lippo]

AFM, AFM, AFM! Check in the tutorial sec. on how to fix them. Very common on R's

[RBRolla]

AFM for sure happened to me on my 32GTR when one wasnt plugged in properly.

[ali-turko]

to check if it your afms next time u get the problem, jump out of your car and bang the afms a couple time see if that changes the idle obously do it with the car still running

[Spunky Munky]

I'd say AFM, loose hoses FMIC or leakage from BOV. Check all your hosing and connections.

[Line]

I've checked the AFM's just now, they seem fine. No dry solder points.

I'll try checking all the hoses, bov. I hope it is something easy like this.

It's just strange though, I've read some people were having this issue when hitting a bump on the road.

But mine first happened when I was stopped at the lights.

I don't think it is the AFM's unless one of them is faulty itself. The solder points seem fine.

It's just really intermittent. I drive for 3 hours the other day with no problems. then in the last 10 minutes it occured again

When I pulled them out, I checked the connections. Seemed like the were connected properly.

Any other ideas?

Thanks

Edit:

I've just noticed in one of the AFM's there is alot of dirt or grease in the centre piece where the air flows through...

I couldn't see this until I put a torch on it, the other AFM is completely clean.

Would it be possible this is causing the problem?

Edited December 28, 2007 by Line

[Lippo]

Yeah, any dirt or oil on the sensor is bad news. Get some carby cleaner or brake cleaner etc, and give the sensor a good spray and let it dry. Do you have an air filter that you oil? If so, clean it and cut down on the amount of oil you use to re-oil it.

[Line]

I've just taken the pod filters out. They are HKS pod filters. They are not in good condition. I'll need to replace them.

I guess this might be why I'm having these problems.

Now to find out where I can buy them lol.

Hopefully cleaning out the AFM and replacing the filters will fix my problems.

Thanks alot for all the help

[ssshonky]

I would suggest going to the bother to get specific electrical contact cleaner.

some of those other cleaners mentioned might cause problems with the plastic near the AFM's

There are some " 3a racing filters " going around that are cheap ( $20 ) but supposed to filter and flow quite well . Maybe just get 2 of those and see if the problem improves.

its not one of those HKS mushroom ones is it?

  Line said:

I've just taken the pod filters out. They are HKS pod filters. They are not in good condition. I'll need to replace them.

I guess this might be why I'm having these problems.

Now to find out where I can buy them lol.

Hopefully cleaning out the AFM and replacing the filters will fix my problems.

Thanks alot for all the help

[ali-turko]

check your spark plugs!

[Line]

Yeah, its the dome shaped(Mushroom) pod filter.

Do you know where I can buy these 3a Racing Filters? Would normal car stores sell them? Autobarn etc?

I've been looking online, I've seen the ones I need. I know I can get them if I buy online but wondering if any local shops(Canberra) would sell what I need.

I don't know if its normal, but the filters themself look abit cheap..when I took them out. I was very careful and noticed it was starting to get a small tear on the outside. One is very bad, while the other looks like it is just starting to happen. I'd assume these have not been replaced in a while.

I'll clean the AFM sensor, replace the filters once I get them.

And the spark plugs! lol

Hopefully it fixes it

[ali-turko]

dont buy cheap shit for your gtr, u can get ti apexi air filter kit for about 250-300

[Line]

Well it has a HKS kit on it now; so it's not really cheap. I'm only looking for the filter itself and not the kit.

I've found a place I can buy the HKS replacement filter, so its all good.

Will have to see how to goes once I get them tomorrow.