Boost cut and misfire on first hard boost

[Scoobychris]

Just got the exhaust blow sorted and now Scooby is boosting perfectly......almost....after first boost I get misfire which then slowly sorts itself out, after this boosts ok but on hard acceleration it hits a wall literally stops dead as such in terms of boost

Its running apexi ecu and has the boost controller which has been disconnected from hoses etc but still lights up

Has anyone got any ideas to help

[Scott.T]

I'm not sure what you mean when you say the Apexi is running a boost controller but it is disconnected.
What is controlling the boost if the boost controller is disconnected ?

Are you running the standard boost control that's driven from the Apexi PFC hand controller, or an Apexi-AVCR that has it's own controller (and the Apexi PFC set to 'off' with regard to boot control)

[Scoobychris]

This is what I have inside but was told it was disconnected from boost solenoid or wiring unsure which

[Rdlangy1]

Hi Chris - big E is desperately seeking ur Xmas meal order on the meets and events page

[Scott.T]

Originally Posted by Scoobychris

This is what I have inside but was told it was disconnected from boost solenoid or wiring unsure which

Without knowing how it's set up for boost control it will be near impossible to diagnose
Does the Apexi AVCR read a boost level ? Is so, what level ?
Does the car run differently if the AVCR is switched off ?
Does the Apexi ECU hand controller provide a boost reading ? It shouldn't if it's set to use the AVCR.
Do you know if the standard gold coloured boost control solenoid is still plumbed in mechanically and electrically. This is mounted to the drivers suspension strut.
Do any of the small boost pipes between the turbo outlet nipple and the actuator connect to anything electrical ?

[Scott.T]

Your boost solenoid looks like this. But this is a 3 port, you may only have a 2 port, so ignore the pipe that comes straight out the bottom ;

[Scoobychris]

I know the avcr doesn't read a boost figure not sure on the hand commander how to get Reading? I will take pics of boost control solenoid

[Scott.T]

Press 'prev' button until you see 'Monitor' on the screen.


Use arrow buttons to highlight 'Monitor, then press 'Next'


Use arrow buttons to highlight '1 Channel', then press 'Next'


Use arrow buttons to highlight 'Boost', then press 'Next'.

[Scoobychris]

This is how mine looks lol mass of pipes and wires that don't look right to me

[Scott.T]

Shot out to garage and added pics to above.

[Scoobychris]

Thanks I will have a look on my lunch and see what's what

[Scoobychris]

Thanks for that just checked and the hand Controller does show boost reading so that seems OK but still not sure why I'm getting boost cut could it be the map is wrong?

[C. J.]

Please take this to a mapper before it goes pop !

[Scott.T]

Originally Posted by Scoobychris

Thanks for that just checked and the hand Controller does show boost reading so that seems OK but still not sure why I'm getting boost cut could it be the map is wrong?

What boost peak level does it read just before cutting.
It sounds like the boost target is too low and the safety fuel cut is kicking in. Or your boost control solenoid is jamming.

On the controller go to 'settings' and 'boost' and photo the screen.
Post up the results.

[Scoobychris]

Will get some pictures later can any one recommend some one to map who can be trusted with with apexi

[Scott.T]

Originally Posted by Scoobychris

Will get some pictures later can any one recommend some one to map who can be trusted with with apexi

You need to sort out the fundamental running issues before approaching your mapper, as they is a good chance there are plumbing or mechanical issues and not ECU related. You mapper may well turn you away if the issue is not sorted/diagnosable by mapping.

There is also a possibility the mapper will work around the issue rather then resolve it. This is never a good idea as there's only one winner in this situation and it's not the customer.

[C. J.]

Originally Posted by Scott.T

You need to sort out the fundamental running issues before approaching your mapper, as they is a good chance there are plumbing or mechanical issues and not ECU related. You mapper may well turn you away if the issue is not sorted/diagnosable by mapping.

There is also a possibility the mapper will work around the issue rather then resolve it. This is never a good idea as there's only one winner in this situation and it's not the customer.

If it's a plumbing issue then most mappers would resolve the issue and if mechanical ask you to resolve it and then come back . At least the three I've used would

[Scott.T]

Originally Posted by C. J.

If it's a plumbing issue then most mappers would resolve the issue and if mechanical ask you to resolve it and then come back . At least the three I've used would

Just trying to save ScoobyChris a trip, and money, if it could be diagnosed via forum communications. The Knock reading and CEL would be going mental if things were off spec, which is the next thing if the boost can be controlled.

[C. J.]

Would it not be easier if he popped round off boost for you to look at then ?

[Scott.T]

Originally Posted by Scoobychris

This is how mine looks lol mass of pipes and wires that don't look right to me

Apologies, first time I have been able to look at those images full size.

The OE Boost controller is disconnected both electrically and mechanically and the OE MAP sensor is still connected. Hence why the Apexi Commander is giving a boost reading.

The Apexi AVCR boost controller is plumbed in, and somewhere there should be a corresponding MAP sensor. As the Apexi AVCR is not reading boost I would assume that this MAP sensor is not plumbed in, connected or missing.

The MAP sensor is the item in the middle of this image :




The Apexi commander 'should not' be reading the boost levels with this setup as the 'Settings' should be such that 'Boost Control' is turned off.
This allows the AVCR to have control.
This is achieved within the 'etc......' menu option, but the On/Off option is in Japanese !!!!!! You will know when you have this set 'Off' as the APexi commander will stop reading boost.

In order to try and get boost under control I would advise that for the moment you re-connect the OE boost controller to it's electrical connector (which is probably now connected to the AVCR) and move the boost hoses from the AVCR to the OE boost control solenoid.
This will at least get the boost under some sort of control.

[Scott.T]

Originally Posted by C. J.

Would it not be easier if he popped round off boost for you to look at then ?

I was trying to save him some money

[Scoobychris]

Brilliant thanks Scott T I will try this and see how I get on great to have some help without having to spend at this stage