Hesitation under initial boost

[rossonza]

completely resolved, im 99% it was just that dead/dying HT lead. car pulls great now

[rossonza]

Well my Walbro died due to rust in my tank.

I've cleaned the tank and replaced fuel filter and fuel pump.

However my hesitation is back. Town driving and idles spot on.

If I foot to floor in neutral it revs up to 5k ish and won't rev past.

If I floor it in any gear it revs cleanly then boost starts to come in and the car surges. Boost seems to come in and out. A few times I've had massive back fires.

As part of fault finding I replaced my HT leads and coilpack.. as you can see this was due badly.





However after replacing that I've still got issues....

Any help at all as this is bringing me to breaking point with the car. Tempted to just sell it as is.

Planning to get a wideband on it tomorrow and a boost gauge.

[markstevieandmads]

Id replace the ignitor.

Also if its a rev 2 turbo then check ecu for leaking caps

[rossonza]

Id replace the ignitor.

Also if its a rev 2 turbo then check ecu for leaking caps

It is indeed rev 2 turbo. I'd read caps more likely to cause bad idle. But I'll give it a check.

Where can I source an igniter?

[Draven]

Leaking caps can cause any number of different issues.

[rossonza]

Leaking caps can cause any number of different issues.

Ok thank you. It's on the list.

I've actually got a DIY megasquirt partially built at home. So may just hurry up and finish that if the caps have leaked.

[rossonza]

Ordered capacitors. Hopefully arrive soon.

[markstevieandmads]

Unfortuantely its not just the caps that cause the issues.
They leak and corrode the tracks so 9/10 you will have to repair tracks too.

[rossonza]

Unfortuantely its not just the caps that cause the issues.
They leak and corrode the tracks so 9/10 you will have to repair tracks too.

Not a problem. I look forward to it lol

[rossonza]

Took the ECU apart




Just the top cap looks to have leaked. I've got them all on order anyway. So I'll get them replaced as a precaution. Rest of the boards look absolutely fine/spotless.

Fingers crossed that's my issue.

[rossonza]

Replaced all the ECU capacitors. Same issue
Replaced igniter same issue

Had a poke around and found my vtv is broken.....

Can I just fit an aftermarket bov and throw all the vtv and stock bov away? Is this likely to cause my issue?

[chrisE]

Just saw your wanted posts for the igniter (ignition module) then came across this so wanted to try and help..

Are you recirculating the bov or is it dumping to atmos? You don't appear to mention this anywhere. Black plugs mean it's running rich (sorry if you know this), so I'm wondering if the bov is leaking metered air...

Check if bov is recirculating and check the valve is working ok (ie. not leaking under boost), and you cleaned the ignitor/coil bracket of any corrosion (it's a ground point).

What does your boost gauge read on idle and on boost? Have you tried setting the actuator to wastegate pressure eg. capping the actuator and turbo ports and disabling the boost controller? This will prove if there's a leak..

If all else fails, I have a used & tested ignition module from my rev3 turbo you can have..

Regards,
Chris

[rossonza]

Just saw your wanted posts for the igniter (ignition module) then came across this so wanted to try and help..

Are you recirculating the bov or is it dumping to atmos? You don't appear to mention this anywhere. Black plugs mean it's running rich (sorry if you know this), so I'm wondering if the bov is leaking metered air...

Check if bov is recirculating and check the valve is working ok (ie. not leaking under boost), and you cleaned the ignitor/coil bracket of any corrosion (it's a ground point).

What does your boost gauge read on idle and on boost? Have you tried setting the actuator to wastegate pressure eg. capping the actuator and turbo ports and disabling the boost controller? This will prove if there's a leak..

If all else fails, I have a used & tested ignition module from my rev3 turbo you can have..

Regards,
Chris

Hi Chris thanks for the reply.

It's stock recirculating. I've found my vtv has cracked. So I've temporarily repaired it. Just waiting for the glue to dry at the moment.

I've just removed the pipework off the turbo cold side and the bov moves in and out no issue. As part of fault finding I removed and cleaned all grounds i could get too. Especially the coil/igniter bracket.

My standard boost gauge shows 0 boost at idle. I've got some videos of the issue which I'll try and get uploaded now to show the issue first hand. I don't have any sort of boost controller installed at this time. I'm running stock boost.

I've had. 2nd hand igniter arrive and it didnt fix my issue. But then this could be a broken igniter also

[rossonza]

Videos of the issue

https://youtu.be/5zbWj9KdZow

https://youtu.be/7FckbR_tQrM

Both videos I'm holding foot flat to floor.

[chrisE]

Videos of the issue

https://youtu.be/5zbWj9KdZow

https://youtu.be/7FckbR_tQrM

Both videos I'm holding foot flat to floor.

Looks like you've got overboost going on there. Check the 6mm hose going from the turbo to the actuator to make sure it's not split. Check the rearward-facing actuator hose going to the TVSV and check your TVSV is still connected to the ECU (blue plug on the TVSV, under the intake manifold).

[rossonza]

Videos of the issue

https://youtu.be/5zbWj9KdZow

https://youtu.be/7FckbR_tQrM

Both videos I'm holding foot flat to floor.

Looks like you've got overboost going on there. Check the 6mm hose going from the turbo to the actuator to make sure it's not split. Check the rearward-facing actuator hose going to the TVSV and check your TVSV is still connected to the ECU (blue plug on the TVSV, under the intake manifold).

Shouldn't overboost throw a code?

[rossonza]

Rigged my boost gauge in.

https://youtu.be/YVVWbl0rCAM

https://youtu.be/yVG79qhs-ZY

Making 5 psi ish on the drive foot to floor in neutral.

7 ish driving 2nd gear foot to floor

9/10 bit hard to see if 5th gear foot to floor loading the engine.

[SonicSW20]

Have you checked:

* ignition timing
* distributor itself - cam position signal comes from the distributor, so damaged wiring, oil leaks etc here will make it run like xxxx.
* TPS calibration
* AFM
* fuelling / fuel pressure
* mechanical timing

Have you checked for codes since the last bits of work were done?

[rossonza]

Have you checked:

* ignition timing
* distributor itself - cam position signal comes from the distributor, so damaged wiring, oil leaks etc here will make it run like xxxx.
* TPS calibration
* AFM
* fuelling / fuel pressure
* mechanical timing

Have you checked for codes since the last bits of work were done?

I need to recheck timing. But everything is done up tight. So can't see how it would have moved. Still. Will check.

Distributor is brand new. Pulled it yesterday. No oil. Or moisture.

TPS. I removed and it didn't seem to make any difference at all... So possibly dead tps...

[SonicSW20]

Did you calibrate it when you reinstalled it? TPS is a very simple device, if it calibrates correctly then its fine.