MY08 GT spec.B Wagon hesitates to accelerate... sometimes

[Stubott]

Hey guys. First post so go easy.

Ok I bought my Wagon a few weeks ago and I'm Totally head over heals with it.

Last weekend I finally got a chance to take it up the hills to see whats what and noticed this problem. As the car accelerates it will sometimes (most of the time it's fine) drop power then come back. Sometimes it's fairly dramatic, sometimes it's subtle. The most dramatic example was going up a steep hill coming out of 1st at high revs in to 2nd, was accelerating for maybe 1 second in 2nd then it cut power and came back.

The only mods on the car, as far as i know, are custom exhaust tips (mufflers are gone) and a cheap stupid boost gauge.

My novice guesses would be:
- maybe the boost gauge is taking its pressure signal from somewhere it shouldn't be
- possibly the engine may be or may think it is receiving too much boost (stock tune though....so i dno)
- spark plug problem

Beyond that I've got no idea. I'm going to investigate this weekend and what I'd love from you guys is some pointers on what the problem could be and what to look out for to help diagnose it.

Any help would be greatly appreciated.

Cheers
Stu

[coyote]

Stock tune has a glitch that will cause that.

[alexxxz]

stock tune is terrible, mine was like that too!

[bigBADbenny]

Clean the MAF, but consider a tune...
Link in my sig with details

[bass_straitener]

Completely normal on the stock tune.

Closed loop - Open loop delay set too long to maximise fuel efficiency in the stock tune.

You'll have to learn to live with it, or get it smooth out via an ECU tune.

[Newbie GT]

A tune will resolve this. This is stock behaviour

[Stubott]

Far out.

Benny I'll check out the MAF this weekend. Also incredible write up on the pre-tune mate, awesome stuff.

Thanks heaps guys, fairly unanimous with the stock tune issue. Looks like I'd better get prepped for a tune.

Cheers
Stu

[Newbie GT]

Far out.

Benny I'll check out the MAF this weekend. Also incredible write up on the pre-tune mate, awesome stuff.

Thanks heaps guys, fairly unanimous with the stock tune issue. Looks like I'd better get prepped for a tune.

Cheers
Stu

Hi mate don't play around with the MAF at all it a delicate situation/part.

It's a tune and your set for a smile on your dial .

[Stubott]

As I understand it cleaning the MAF involves removing it carefully and spraying a dedicated cleaner on and not touching it in the process. I've got plenty of experience with cleaning delicate electrical equipment from work so I'm confident I can clean it, but if you think it's not worth the risk I'll leave it alone for now.

[asfletch]

I recently cleaned my MAF using CRC MAF cleaner and it didn't solve my similar issue (thought it did for a week but then it came back). Still, the bulb was dirty (black), so it was probably worth doing anyway. It didn't make anything worse, is my point I guess

[alexeiwoody]

As I understand it cleaning the MAF involves removing it carefully and spraying a dedicated cleaner on and not touching it in the process. I've got plenty of experience with cleaning delicate electrical equipment from work so I'm confident I can clean it, but if you think it's not worth the risk I'll leave it alone for now.

A clean maf is very important. It's part of your service procedure for good reason.

Newbie - why troll for?

[Newbie GT]

As I understand it cleaning the MAF involves removing it carefully and spraying a dedicated cleaner on and not touching it in the process. I've got plenty of experience with cleaning delicate electrical equipment from work so I'm confident I can clean it, but if you think it's not worth the risk I'll leave it alone for now.

A clean maf is very important. It's part of your service procedure for good reason.

Newbie - why troll for?

Just my opinion alexi

[Manaz]

As I understand it cleaning the MAF involves removing it carefully and spraying a dedicated cleaner on and not touching it in the process. I've got plenty of experience with cleaning delicate electrical equipment from work so I'm confident I can clean it, but if you think it's not worth the risk I'll leave it alone for now.

A clean maf is very important. It's part of your service procedure for good reason.

Newbie - why troll for?

Just my opinion alexi

Yes, the MAF is delicate. But you'd have to be a ham-fisted moron to do damage to it if you clean it following readily available instructions (the can of CRC MAF cleaner I grabbed from SCA last week clearly tells you exactly what you have to do).

Instructions:

1. Open the bonnet.
2. Locate MAF on the air intake tract (just after the airbox).
3. Remove the two philips head screws holding the MAF in place (don't drop them into the engine bay, or anywhere else for that matter!).
4. Gently pull the MAF out of the inlet tract. You can optionally remove the cabling connected to it, but there's plenty of play in it (certainly enough to clean the MAF).
5. Using MAF cleaner, follow the instructions on the can (which will say something like "Spray the MAF bulb 10-15 times, don't touch it with your hand, the spray nozzle, your dick, etc).
6. Gently put the MAF back in the inlet tract.
7. Do up the screws. Don't overtorque them, you're not building the harbour bridge.
8. Close the bonnet.
9. Win.

[Kekotic]

The bulb is the air temp. The maf is the two tiny wires inside the housing which can be seen by shining a light inside.

[alexeiwoody]

Nice write up mr manaz ( and kekotic)

Don't forget to wait a few hours before driving so the MAF can dry out.

The alcohol dries nearly instantly when spread on a surface but it tends to collect inside the housing after spraying inside and you don't want it dripping onto your sensor while you're driving.

And as Kieran said, it's the wires that are the sensor with the bulb being only the temp sensor, and you want to spray/clean both