Idle pulsing

Posts specific to the 2.0 litre Turbo engine

Idle pulsing

Postby thirsty » Tue Feb 12, 2019 8:39 am

Hi all, I have an 04 GT auto that has developed a really annoying pulsing idle. After coming to a stop the car will idle down every second or so and has even stalled when my wife's been driving it. I've had a tune done by a reputable place, the car has silicon intake and turbo pipes and a new 265lph fuel pump and filter fitted.

I've done the idle learn procedure a couple of times which seems to fix it for a very short while but it always comes back.

Any ideas?
thirsty
 
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Re: Idle pulsing

Postby bigBADbenny » Tue Feb 12, 2019 8:47 am

Possibly an inlet leak.
If you google your exact issue it might be a post throttlebody leak.
Or a failing throttlebody.
https://www.google.com.au/search?q=suba ... ent=safari
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Re: Idle pulsing

Postby bigBADbenny » Tue Feb 12, 2019 8:53 am

Tl/dr: eg avcs or o2 sensor... logging with Btssm or Romraider is something to have if you’re tuned or not :)
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Re: Idle pulsing

Postby thirsty » Tue Feb 12, 2019 4:38 pm

Ta, I have a Evoscan but it only updates every couple of seconds so pretty much useless. I emailed the manufacturer about that and he never responded. I was thinking about the avcs banjo bolts filter issue as that seems a common problem. I've replaced the problematic O2 sensor when I had a surging problem under power - that problem was solved but not the idle issue.
I may have to take the car back to the tuner and ask them to log it for me.
thirsty
 
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Real name: Tony

Re: Idle pulsing

Postby bigBADbenny » Tue Feb 12, 2019 5:03 pm

I’m not sure about evoscan, but if you can see 4x vvt angles, just log those vs rpm, vehicle speed, maf, throttleplate angle, accelerator pedal angle.

Less parameters usually means more resolution. Or the USB connection baud rate is improperly configured, refer to the evoscan manual.

Prefl vvt issues can be failing ocv’s or exhaust ocv loom oil contamination from the ocv plug all the way back to the ecu, in addition to sludged banjo bolt filters.

Thus log the suspected parameters at the rpm’s affected, but also at freeway cruise, and see if you can very gently provoke rpm hunting around idle to 2000rpm whilst in neutral.
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