Manual Fg Hesitating On 1-2Nd Gear Change Only

[rockafellqeinstien]

Ok, I know I'll fix this but thought it put it out there in case any one has had this problem and to record my solution if no one has.

Car has been running fine for last 35,000 kms (total 230,000km) since last tune (few little issues like loose hoses or loose batery connection but tracked them down and fixed)

now on snappy high rpm 1st to 2nd gear changes (manual) it bogs down for a second or less (sometimes twice - eg, change, bog down, power, bog down , power). if I just boot it in 2nd it will go through the full rpm range no problems

car runs fine in all other gears and gear changes (400rwk gtx with cold side intake and simmy valve)

SO I am thinking it could be one of these causes.

1)boost leak - engine torquing during the gear change is enough to cause a lake somewhere

2) dodgy electrical connection showing up due to torquing

3)sticky or slow actuator -

4)crappy solenoid (have wd/40'd it to test with no change)

5)bov not working right

6)spark plugs

7) simmy valve opening a bit due to boost spike on change (checked this and couldnt see it opening)

excess fuel during change(leaky injector?)

I did a quick Leak test of the IC at low pressure and couldnt see any leaks but need to take the under tray off to see the IC connections.

as I said, I'll figure it out but am putting it out there for advice

no codes and turbo presure drops to 5 psi but that could indicate a leak or the engine makes no power so no boost (doesnt help either way)

any advice appriciated

[Ralph Wiggum]

Ask your tuner if he made any changes to the torque managment settings in the current tunes. If no mechanical issues it sounds like shift torque truncation or possible traction control torque reduction?

[masda74]

I put my bets on traction control being that you have a manual.

If I use the launch control for 1st and launch the car pretty hard, when I change to 2nd, it's like the car is loosing power, but it is DSC preventing the wheels from spining.

it has only happened to me twice and I don't like launching the car at all, so it hasn't happened again.

Could it also be a faulty sensor at the rear for the DSC? If there is such a thing?

[rockafellqeinstien]

well after a lot of testing and checking parts and connections I finally found my issue (might save someone else some headaches)

it was the BOV. It was leaking a little boost and for some reason the 1-2 change caused some weird voodoo boost craziness on gear changes where it would loose almost all boost and take a little bit to spool back up (BOV might have been binding on something) - it had been getting worse for about 2 months.

I checked every electrical connection, intake pipe join, actuator and solenoid (all working fine by the way). Finally I was thinking it could be the BOV so I just crimped the BOV line and it fixed it - although now I get super duper turbo flutter which is quite,um , loud.

So I'll be looking for a new BOV (or I could just delete it but my car is loud enough with out the extra loud flutter)

to be fair - it had exactly the same feeling as traction control but that was the first thing I checked (Turning off TC is a reflex action every time I start the car now- had to check I turned it off because I couldnt remember doing it - but I did)

[masda74]

Thanks for the update Rokafellqeinstien. I have been trying to track this thread down for a week now and couldn't remember where it was located.

Checked my unread content today and whalaa.

Glad to hear that it is resolved now.

I will keep this in mind for future.