Strange Surging Problem

[NYL83R]

Bit hard to explain, but having a surging problem when travelling at a constant speed (only happens over 100km/hr)

Happens at various speeds over 100.... eg 110, 115, 120. Only does it if i hold the accelerator at a constant speed. as soon as i de-accelerate or speed up it goes away. It also does not surge at a constant speed up hill (so shows it is not a problem under load)

I have changed the plugs, oil, oil filter, fuel filter, reset the ecu, changed the timing belt, had a code check... but no luck. I have also tried going back to 3rd gear in case it was a top gear problem... still no results.

I think its just a conicidence, but this surging problem started around the time I did an oil change and replaced the fuel filter...... could the new filter be a problem...?

Any help or suggestions would be great. I've had enough of this problem

[scotty nm35]

Try cleaning the AFM mate, do you run an oiled air filter?

[SHETLANDER]

would the revs be between 2-3000 that it surges? what kind of petrol are you using?

[17yostagea]

Fuel filter in right way

And yes clean AFM and throttle body

[NYL83R]

Forgot to mention that....

Already cleaned the throttle body, the AFM, and the air filter. I have a K & N Filter.... oiled

also replaced the foam seal around the snorkel (filter had lots of foam sitting on it from the old seal...

Running V-Power

hmmm, can't remember the revs it is sitting on at 110 (in 'D')

Edited April 28, 2011 by NYL83R

[SatchiThaStagea]

Probably waaaay off but I had a similar problem when I had my alarm installed.

Turns out the guy installing it hadn't clipped the the little plastic clippy thing into the positive terminal properly, it seemed in but it wasnt and i only had symptoms at 90klicks

[Dr.J]

Mine did this too on a recent long distance trip. I would wind her up, then go to overtake only to have this surging nonsense, and the speed only increasing marginally.

It was definitely pissing me off.

The last time I drove a car that did this, it turned out the cooling system was partially blocked = Not flowing enough coolant.

I will investigate!

[NYL83R]

When I changed the timing belt, I also replased the thermostat, flushed the system and replaced coolant

Only surges when doing a constant speed.... the car will accelerate fine with no loss of power

I'll check the terminals....I'll try anything at this stage

[17yostagea]

Did you bleed ALL the air out of cooling system???

[NYL83R]

yep, its all good

[scotty nm35]

O2 sensor reading incorrectly? I think you need a scan tool on it when the surge occurs.

[NYL83R]

Yeah I was thinking that was an option.... plug in a scan tool and take it out on the freeway.

[zebra]

Sounds like compressor surge

Do you have the Standard BOV or and aftermarket jobbie?

Ps I hate the word BOV....please dont make me say it again lol

[NYL83R]

I do have an aftermarket BOV (blitz) but it had this surging problem before I put it on....

I only stuck it on for a bit of fun cause i was changing the plugs and had it sitting in the cupboard

The more i'm thinking about this, I am thinking it could be the fuel filter. Perhaps the new one I put on is a dud or not compatible... I saved the old one just in case, so I'll stick that on tomorrow and see what happens

[NYL83R]

well.... digging back into this thread to have another go

I am still having the problem mentioned above. I've changed back to my old fuel filter thinking that was the problem. but no luck. I was suggested to try another AFM. I've already cleaned mine, but could be a dud? Anyone have a spare they would be willing to lend me? big ask, but i don't really want to buy a new AFM on a hunch.

[frigjam]

Does it feel like the whole car is jerking slightly? Do you often hear the Attessa relay click in the engine bay? (located driver side strut tower).

Because thats what mine was doing. Turns out it was the 4WD system playing up. The 'accumulator' was buggered, it is a high pressurised cannister that holds Attessa pressure up to the system. There's a few threads about it on SAU, common to GTR's and GTS-4s also.

Just an idea...

Cheers

Paul.

[AAA34T]

well.... digging back into this thread to have another go

I am still having the problem mentioned above. I've changed back to my old fuel filter thinking that was the problem. but no luck. I was suggested to try another AFM. I've already cleaned mine, but could be a dud? Anyone have a spare they would be willing to lend me? big ask, but i don't really want to buy a new AFM on a hunch.

I have had the same problem years ago when i was using a k&N air filter the oil distroys the afm and u never get it all out i went to a use a paper air filter and cleaned the afm was heaps better but still did not totaly fix it till i replaed the afm and now i only you paper air filters and no more problem

[GTR260]

Does it feel like the whole car is jerking slightly? Do you often hear the Attessa relay click in the engine bay? (located driver side strut tower).

Because thats what mine was doing. Turns out it was the 4WD system playing up. The 'accumulator' was buggered, it is a high pressurised cannister that holds Attessa pressure up to the system. There's a few threads about it on SAU, common to GTR's and GTS-4s also.

Just an idea...

Cheers

Paul.

I agree and think it has something to do with the atessa system. How did u diognose ur accumulator was the problem?

[KiwiRS4T]

If you have a S2 you can switch to 2wd as per the instructions or if your'e keen drop the front driveshaft to eliminate the attessa. Are all your tyres the same type and roughly the same state of wear? ( I think this unlikely as your cause but its easy to eliminate). I can send you an afm. Only trouble is I am assured it is good but not using one now as I have a G4 Link computer. Have you eliminated the O2 sensor? I think the easy way to do that is to just unplug it and go for a drive.

If you want to try my afm I just want the postage at this point and worry about the rest later (AU$60 to buy, postage probably about $20 - can let you know if interested).

[NYL83R]

thanks for the help guys. hmm I don't hear any clicking paul, would it be a noticable clicking when the problem starts? Yes the whole car jerks slightly. It could be my imagination, but since having this problem the car seems to have slightly less power overall? i'll investigate further. Could very well be the k&n oiled filter i have, after hearing what people are saying. I've had the filter in for a couple of years though before it started having this problem

I'll try unplugging the 02 sensor if you think it might help bob, otherwise I will take you up on that offer please. can you pm me bank details. cheers