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Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Thu May 21, 2015 5:31 pm
by Bronald
Holding 1500 rpm

Image

3000 rpm stabs of throttle

Image

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Thu May 21, 2015 6:02 pm
by bigBADbenny
What app are you using?

Btssm info:
viewtopic.php?f=56&t=27506

With btSssm and its BT plug (or tactrix via otg) you can log both vvt angles.
Get a btSsm for convenience of gauges & logging, or a tactrix for flashing & logging to pc or android w/ btSsm.
Your choice, I have both options ;)

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Thu May 21, 2015 11:09 pm
by Bronald
bigBADbenny wrote:What app are you using?

Btssm info:
viewtopic.php?f=56&t=27506

With btSssm and its BT plug (or tactrix via otg) you can log both vvt angles.
Get a btSsm for convenience of gauges & logging, or a tactrix for flashing & logging to pc or android w/ btSsm.
Your choice, I have both options ;)


I will probably invest in one after all this!

Did UEC today. No difference.

Plugs I pulled out looked new! I replaced them with four OEM items. No real change.

What a pain in the ass plugs are... Jesus.

Solenoids will be here Monday.

Any idea if the codes on the earlier page (not misfire) are related to my issue?

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Fri May 22, 2015 7:59 am
by dr20t
I do owe you $50

Intake air temp and mass air volume are both related to the maf sensor (the long probe in these sensor is the air temp sensor).

Try swapping maf sensors with a known working one and if it fixes it, buy a new one for yourself

If symptoms persist after you swap them out, check all your wiring to the mad sensor or the plug itself.

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Fri May 22, 2015 10:40 am
by Bronald
dr20t wrote:I do owe you $50

Intake air temp and mass air volume are both related to the maf sensor (the long probe in these sensor is the air temp sensor).

Try swapping maf sensors with a known working one and if it fixes it, buy a new one for yourself

If symptoms persist after you swap them out, check all your wiring to the mad sensor or the plug itself.


Thanks for that!

Would a dirty sensor also throw a code? It was filthy when I checked it.

I assume if it's malfunctioning it'll throw another code again.

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Fri May 22, 2015 11:57 am
by dr20t
Yep dirty maf can definitely do that

Clean it with maf sensor cleaner (make sure its the right one) and it will tell you if its still faulty

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Fri May 22, 2015 9:23 pm
by Bronald
dr20t wrote:Yep dirty maf can definitely do that

Clean it with maf sensor cleaner (make sure its the right one) and it will tell you if its still faulty


Cleaned it. Hasn't thrown a code.

Put two new solenoids in. Feels smoother stationary @ 1500RPM, but is still hesitates and jolts on WOT when it comes on boost.

Any ideas what the fuel trim / AFRs should be, or what else I should be looking for?

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Sat May 23, 2015 2:08 pm
by Bronald
Update: fresh tank 98 and new battery ground and its 100% better!!

Thanks for your all your help guys! I'll report back if I have further issues.

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Sat May 23, 2015 10:59 pm
by bigBADbenny
Nice one, an ECU reset is a good idea after making any changes it provides a clean slate :)
If not reset, changes can take longer to show any improvement, iirc...

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Sat May 23, 2015 11:35 pm
by Bronald
bigBADbenny wrote:Nice one, an ECU reset is a good idea after making any changes it provides a clean slate :)
If not reset, changes can take longer to show any improvement, iirc...


Makes sense.

I find after a reset the car's a bit jerky, but that's just it learning the parameters I figure. After a few drives it finds its feet.

For the ground replacement, I used this

Image

Works well.

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Sun May 24, 2015 9:29 pm
by norbs
Is that the one that goes from the -ive batt terminal to the LHS strut tower?

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Mon May 25, 2015 8:56 pm
by Bronald
norbs wrote:Is that the one that goes from the -ive batt terminal to the LHS strut tower?


Bingo.

Was going to make my own, but for $25 off the shelf with mechanically crimped ends its far better than what I can do with a Jaycar crimper and some terminals!

Just make sure you sand off a bit of paint so your contact patch for the ground is adequate.

My lights are brighter, lock/unlock courtesy lights power up fast and bright, can only assume sensors are getting more juice as a consequence.

Looks factory too.

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Mon Aug 24, 2015 12:52 pm
by JamesR
This kinda sounds like a problem my MY07 GTB has started doing.
It revs up to 2000rpm fine, but seems to struggle past there, unless I really put my foot down.
Even on cruise the revs don't settle.
It kinda feels like the auto is slipping, but I guess if it was the case the revs would be high, and the speedo would be jumping around.

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Tue Aug 25, 2015 7:10 am
by bigBADbenny
I'll be in Moe this Saturday arvo if you'd like assistance with the diagnosis :good:

Re: '07 Liberty GT-B severe hesitation / Misfire

PostPosted: Sun Sep 27, 2015 9:09 pm
by EVL20T
JamesR wrote:This kinda sounds like a problem my MY07 GTB has started doing.
It revs up to 2000rpm fine, but seems to struggle past there, unless I really put my foot down.
Even on cruise the revs don't settle.
It kinda feels like the auto is slipping, but I guess if it was the case the revs would be high, and the speedo would be jumping around.


I have same problem with my 07 GTB, cruising at 2500rpm the car fluctuates, put your foot down and it struggles then takes off