Very Flat When Accelerating .. And Surges And A Whole Heap Of Problems

[Scooby_Steve]

Hi Guys,

Just hoping someone can point me in the right direction.

I've got a 96 R33 GTST with K&N Pod, 3" Zorst, BOV and FMIC with boost around 11-12psi (done by a Turbosmart manual bleeder value).

When i go to accelerate (overtaking on the highway) you can hear the pod filter etc going crazy sucking in air but the car doesnt really take off (it used too and it isnt just that i'm used to the car.. i've had it for 2 years and i know somethings wrong). It will take off but struggles and it surges and then hits flat spots and then surges again all the way up the rev range. Seems like something is holding it back.

I do have dud coils but i have taped them with electrical tape and they seem to be ok for a $10 fix (they are really bad without taping).

I have cleaned my AFM once before when i had a very similiar situation and it seemed to have resolved the problem but i dont want to keep getting this problem. I've only driven the car about 2000kms in the last 6mths (also since i cleaned and re-oiled the filter).

Also when travelling on the highway and going to over take (whether in 4th or 5th gear), if i just hammer it, my car cuts out (like the fuel-cut comming in) but if i slowly climb there is no cut out.

If anyone can suggest where i should look at, i'd appreciate. thanks

[mad082]

well the cut out in 5th gear is rich and retard mode. only way to get rid of that is either new ecu or wind the boost down.

how old are your spark plugs? and what type? that could be part of the problem.

[Guilt-Toy]

clean and regap your existing plugs to .8 - you will be suprised.

sounds like you could be hitting your air flow cut. time to invest in some management

[Scooby_Steve]

Hi,

Thanks for the replies.. Just wondering why when i overtake i 4th or 5th and i slowly put the pedal down it doesnt cut out but when i plant it, the fuel cut comes in... could this be because of a bad bleeder/boost value?

Also, i havent changed my sparkies in a while so maybe i will this weekend and i'll gap them.

Anyways, thanks guys again.

[r33_racer]

wouldnt think the boost controller would have anything to do with the problem. It will just be fuel cut coming in...R&R as stated before, a/m ecu will fix it. Generally winter will bring upon boost spikes and induce R&R more so if you have the boost set right on that threshold and the occassional squirt mixed with colder climate will bring upon that change.

[GTR_STEALTH]

Yer im in a similar situation dude, with the same b/c as urself.....try winding it back a touch....

Originally posted by r33 racer

Generally winter will bring upon boost spikes and induce R&R more so if you have the boost set right on that threshold and the occassional squirt mixed with colder climate will bring upon that change

Exactly wat i thought!

[GTAAAH]

Could be a rooted fuel pump to. Or a clogged filter

Edited July 25, 2006 by r32 gts-turbo

[Scooby_Steve]

Hi,

Might just have to wind the boost down... That seemed to fix the problem too a while back but ...yeah because winters here maybe that's causing it to play up.

[mad082]

the way that r&r works isn't by boost pressure. it isn't just a case of once it reaches a certain pressure it cuts out. that is why it won't do it if you ease the throttle on.

but yes the cold weather has an effect on it. just wind the boost down a bit.

[r33_racer]

I believe its based on measured airflow....is that right?

[mad082]

its based on a ramp scale. i started a thread about this to find out exactly.

what happens is that the ecu has a set maximum airflow per rpm. so if it exceeds that amount it cuts out.

for example, the airflow at 14psi might be within limits at 6000rpm, but not at 3000rpm, so it cuts out. i will draw a graph to illustrate it when i get time.

[Scooby_Steve]

Hi,

So from what you guys have said, i could possibly have a bad airflow meter?

[r33_racer]

haha no...i dont think so...try winding the boost down and see how it goes mate. Take things one step at a time...you never do 5 things to fix one problem or you will never know what fixed it.

Thats also an idea below...try some contact cleaner through your afm.

Edited July 25, 2006 by r33_racer

[mid life crisis]

you mentioned you have re olied your air filter is it possiable some of this oil has found its way onto the wire in your afm ?

[cry41t]

Change your coil packs

[Scooby_Steve]

I didnt notice this problem until last weekend when i went for a long drive and needed to overtake. But the period after re-oiling, i didnt have any problems.

And yes i would love to buy new coil packs but i dont have the money yet.

Well, i'll wind the boost down first and get new sparkies and have em gapped.

Then i'll see how it goes.. I'll clean the AFM anyway.

Thanks guys.. will keep you posted.

[cry41t]

Could be a number of things (as usual) but coil packs usually fluctuate when faulty under load which is what you are experiencing when trying to overtake. Which also explains, that when you decrease the amount of boost you are running that the problem will go away.

Theres plenty of advice throughout these forums to detect faulty coil packs.

[Scooby_Steve]

I forgot to add one thing... could be important.. the car seems to backfire a lot when changing gears or going down hill with no acceleration.

[mad082]

I forgot to add one thing... could be important.. the car seems to backfire a lot when changing gears or going down hill with no acceleration.

thats just due to the bov.

[Scooby_Steve]

Hi All,

I've changed my plugs with NGK BCPR6ES (i think that's it) which are standard gapped to 0.8mm and wound down the boost to run 10 or 10.5 (needle on boost gauge is half between 10 and 11). The 33 seems to run quite well.

However saying that, the old plugs didnt look to bad either but who cares when the car is running much better.

thanks alot.