Td4 manual no power until Turbo kicks in

hi all hoping for a bit of help

Td4 2006 manual

Intermittent starting (worse when warm ) , and it will not rev correctly until the turbo kicks in , at idle foot to the floor it will slowly ( very slowly ) move up the revs and as soon as the turbo kicks in it revs perfect

Fuel filter replaced
Low pressure fuel sensor disconnected / no difference
Maf disconnected - better but no way near perfect
Air filter replaced
All turbo boost pipes replaced
Egr removed and pipe blanked
No eml
No fault codes
Any suggestions much appreciated

Also swapped maf for a known good second hand bosh unit no change

haza88 said:

Also swapped maf for a known good second hand bosh unit no change

Click to expand...

Sounds like an air leak somewhere...check for condition of turbo hoses etc.

Thank u for reply but I have replaced all turbo hoses boost and vacuum

Intermittent starting (worse when warm ) will most likely be the cam sensor, check that out will a good know one if you can,

Ok great will look into that thanks for the reply

have you put the vacuum pipes on correct or has the person before you

Thanks fot the pic checked and all good

Fitted a cam position sensor as was only 35 from local car parts still no change, ‘‘tis now almost dangerous to drive

Have you checked the the rail sensor for corrosion and the replacement harness fitment? Also check all the vacuum pipes, from the receiver across the engine to the boost control solenoid.
You then need to see what the live data is showing for the high pressure rail, low pressure rail and MAP reading.
It won't be the cam sensor, as that's only used for initial starting of the engine.

Thanks for reply replaced cam sensor as my first post starting well is intermittent , no corrosion on conversion loom plug perfect continuity from ecu pins to plug too, vac and boost lines vacuum gauge pressure tested ok live data not yet done but in the list

Ok so quick update as nothing more annoying than finding the fault you have and people not posting the fix

Although no fixed it’s getting ther

Front braks were binding now sorted but worth looking at not always the engines fault

Found both wires going to a sensor in the engine bay fuse box damaged by incorrect figment of lid

Car is better will report back

Does any one no what the sensor in the engine bay fuse box does?

Since wiring repaired the egr solinoid valve now seems to work as makes a whining noise when engine switched off

Ok so had proper drive today it’s still no good any ideas

Sounds like a vacuum pipe, especially the one from the receiver, over the top of the engine, to the boost control solenoid.

OK will double check the vacuum pipes thank u for reply, what’s bugging me is the intermittent non start is back can’t help thinking the faults are related

Idle live data air flow 404.40 low pressure fuel 350 high pressure fuel 28658. 84

Air flow seems low for idle.

Have you tried unplugging MAF and seeing how it drives?

Yes does drive better also swapped with a known good second hand one fault stays the same

Within the ecu is a reset function for the MAF sensor adaption on the facelift vehicles - not sure if your diagnostic kit can reset it - I know T4 can

Interesting haven’t heard of that will look into it cheers for the reply

Update - by passed turbo boost solinoid, now like a different car although think it’s over boosting as keeps going into limp mode on hard boost in third will update next week when new solinoid arrives and has been fitted a tested