Bizarre Engine Jerking/surging - R33 Gts-T S2

[vekra]

Hey,

I'm wondering if anyone can help me out here... I have an R33, it's completely stock, in excellent condition.

First thing I noticed was it started to idle rough, and to sound like it was about to stall. On one or two occasions it stalled. So I took it to Chasers in North Melbourne and they did a moderate service. I told them about the running rough problem and they said they'd check it out. They found the O2 sensor to be faulty and replaced it. They also set the timing etc. back to Nissan recommended settings.

Now it's even worse.

It idles extremely rough (comes close to stalling all the time), and has developed a weird jerking/surging problem when cruising - usually between 70 - 90 km/h. This is usually accompanied by flat spots in acceleration (just before the turbo kicks in). So I took it back to Chasers and they checked it out again. This time they also checked all the electricals, including the alternator, grounding points etc. They checked the air flow meter, as well as every other obvious cause of the problem. They can't find anything wrong and don't know what to do.

Any ideas?

I've had a look in this forum and there seem to be a couple of common problems that could be causes for this:

O2 sensor & installation

AFM: clean AFM, check installation

fuel issue: fuel pump, fuel pump relay, fuel injectors

spark plugs, regap plugs

throttle position sensor

check ATESSA fault codes

coilpacks

air leaks

check MAP sensor

Am I missing anything? Does this sound like something obvious? I'd really appreciate anyone's suggestions... Including recommendations for someone who can test the car and get to the heart of the problem. I'd be really surprised if there's nobody in Melbourne who can fix this. I'm so frustrated that I'm thinking of diagnosing it myself with an ECU interace cable and conzult software etc.

The car's only done 88,000 kms and has always run perfectly until now.

vekra

[DVS JEZ]

Problems like this can be hard to diagnose unless u have a 2nd r33 u can swap parts with,

Things to try-

Disconnect the 02 sensor and go for a drive, any better?

If not

Swap afm with a know working afm and drive, any better?

Swap the ecu with a known working ecu and drive, better?

Swap the coolant temp sensor and drive( will be hot and may lose coolant BEWARE! )

Do a pressure test on the intake system

If above doesnt fix it, put it on a dyno and check air/fuel ratio's and the condition of the fuel pump.

Let us know how u go

[vekra]

Jez,

Cheers for that. I'll have a go at those things, but I'll need to do it with a mechanic's help as I don't have the tools/experience. And yes I don't have another skyline to swap parts with.

I'll let you know what progress I make. Might go back to Chasers and ask them to work through my list and the things you've suggested.

vekra

[AAARGH 33]

Do you drive the car often? Has it been sitting around for a while? Because this happened to me,it turned out to be dirty sparks plugs.I let the car sit around for a while and the carbon built up around the tip affecting the spark hence the rough idle.

Also,have you done a compression test on all six cylinders? Just another possible factor.

[Bsa]

If it had a service I'm sure plugs would be changed. Jez is right that list is your best option. Why was the timing changed it should be at 15 I'm fairly sure

[vekra]

Thanks for the ideas...

I don't drive the car very often - only once or twice a week to get to indoor soccer. I would have thought Chasers would check the plugs as one of the first things they would do, that's if they didn't change them all.

Haven't had a compression test done on it, but that could be another option if all else fails. Don't know if the timing was changed, but during a previous service they may have set it to be more of a daily driver. Chasers tell me they set it to stock/nissan recommended settings.

vekra

[Dre678]

Mate I've got pretty much the exact same problem :s

I've cleaned the afm, aac, throttle body, changed the o2 sensor and changed coil packs. I had changed te coil packs due to a misfire. I really should have done the plugs at the same time.

My idle is pretty good now but theres a difinite lack of power. Huge flats spots. But it's rather intermittent.

I've reset the ecu and it returns no error codes.

I'm taking it to a workshop here in Perth on Tuesday. I'm hoping it's something fixable! Will let you know what they find - if they find something :s

[vekra]

Sounds like you've already done the things on my list...

I was going to do the plugs myself but I've decided to take it to Nissan (although they're reluctant to touch imports because 'it's got them into trouble in the past'), and ask them to replace the plugs and go through the list. Failing that back to Chasers.

I get flat spots too, especially when she's cold. The bigger problems for me are the rough idle and the lumpy running (surging/jerking) when cruising. It's difficult with an intermittent fault because you can't just show it to the mechanic, so in fairness to them, it's hard to diagnose.

I'm thinking dirty spark plugs, because the problems seem worse when she's colder.

After everyone's great suggestions, this is the list (in declining priority order). Will let you know how I go... (and Dre - keep me posted).

THE SUSPECTS

spark plugs: clean, regap, replace

ATESSA fault codes

02 sensor

AFM: clean

ECU, or a sensor feeding ECU wrong data

MAP sensor

coolant temp sensor (seems to run hot)

throttle position sensor

fuel issue: fuel pump, fuel pump relay, fuel injectors, air/fuel ratio(check with dyno)

air: leaks, pressure test on the intake system

compression test all 6 cylinders

coilpacks

Cheers,

vekra

Edited December 4, 2011 by vekra

[Dre678]

Vekra,

My problem hasn't occured since last week... I did end up taking it to the mechanic and after we went for a test drive and he plugged in the consult cable nothing was out of the ordinary

In the last week, however, my fuel consumption has reduced somewhat drastically (with no change in driving atitude). It was hovering around 13.5L per 100kms but on the current tank it's sitting around 10!

I can only wait until it happens again, in which case the mechanic advised to bring the car straight there...

Any update on your end bud?

[Bitsushiti]

Vekra & Drey, are you fellas using the stock AFM? It definitely sounds like the solder joining the AFM plug to the PCB is dry & cracked. I had the exact same problem...

Hitting bumps etc will briefly give you a connection to the plug and the car will run fine, but another bump or two later it will break the connection again, causing intermittent hesitation (especially just as you're about to roll on to boost), surging and shit fuel economy.

It always seems behave itself in the presence of mechanics too

If you have a soldering iron handy, fixing it costs nothing and is a very basic 15 minute job... give this DIY repair tutorial a try:

http://www.skylinesa...your-rb26-afms/

[Dre678]

I did see that, but I had only cleaned the inside...

I'll do this this afternoon and see if it helps, Thanks!

[Dre678]

Bitsushiti, I take your engine light didn't come on before you had re-soldered the joints in the AFM?

Through my entire ordeal, the engine light has never come on - and always reveals the '55' code when I reset it using the paper clip method.

[Bitsushiti]

Sorry mate I can't remember the engine light coming on... if it did, I'd assume it would only do it as the AFM temporarily loses its connection. On top of that I was probably too busy trying to stay in my seat every time it hesitated to notice!

My consult port always returned fault code 55 (no malfunction) as well, mystifying autosparkies and mechanics that were trying to diagnose it.

Considering that the AFM has been exposed to vibration and constant expansion/contraction from heat for the better part of 13+ years, I'd re-solder the plug anyway. Completely cured my problem

[Dre678]

I opened up the afm and the connections were all sound. There looked to be ample solder on them.

There was a little corrosion build up around the pins which I cleaned up. Put everything back and it run sweetly - but I fear it's only a matter of time until it happens again

[vekra]

Firstly, thanks everyone for your inputs/replies here...

I'm back to finish the story.

After getting the O2 sensor replaced, I drove the car and she still had the same problem. Flat, jerking/surging, idling rough intermittently. I took her to Nissan, they tested it, and immediately saw the O2 sensor was dead. So essentially the brand new O2 sensor that had been installed failed straight away.

I took her back to the mechanics who swapped the O2 sensor and they put a new one in (for the second time). I said I wanted her put on a dyno afterwards to make sure everything was fine. Dyno showed there was a fuel pump or fuel ignition sensor problem - the engine wasn't getting enough fuel just as the turbo came on. So they replaced the petrol pump. They also regrounded the wiring for the pump etc.

Now she's running very well... Problem(s) seem fixed. No surging/jerking. Idles smoothly.

Moral of the story? Don't take anyone's word for it when it comes to skyline repairs. Go with your gut. If it feels like it's running strange/flat etc., there's probably something wrong, even if a mechanic or specialist tells you there isn't. Get a second opinion. Don't hesitate to have the car put on a dyno to solve a hard to find problem. If you do have the fuel pump changed, anticipate that they'll screw up the install and check for fuel leaks after driving it for a bit (car was initially pouring fuel - they had to do that twice too).

Hope this helps you all...

Edited December 18, 2011 by vekra