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Discussion Starter #1
Hey all
I'm talking about a 2003 AJT engine(88bhp) 161k on the clock white panel van with practically full service history and owned by a shop fitters company from new till I bought it.

It had no fault codes it has the EGR blanked and the valve cleaned.
It drives fine, its does the speed limit etc but I wondered if it should boost like this.

The turbo is audible from about 1900rpm and the boost is evident, as the van starts pulling harder but this effect tails off at about 2750rpm, the van carrys on pulling but I can't hear the turbo anymore.

Tonight i've watched a few of the dials and numbers on Torque lite.
I noticed the boost peaking at 11psi and then dropping off at 2600rpm, down to about 9psi on the screen as the revs go past 3k, this is in 5th gear.

I thought it test it in 2nd gear, I saw 13psi when I floored it.
The van does not smoke or do anything odd at all and drives really nice.

I'll try unplugging the MAF tomorrow and see if it makes any difference.

Is this boost drop off normal?
 

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Sounds pretty normal.

Your MAF might be a bit down but unplugging it wont tell you anything unless its totally goosed.
 

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I had one of these vans from 2 years old, and it seemed flat, and the boost seemed to die away almost as soon as it had come on. I unplugged the MAF, and instantly got loads more power. Bought a new one from GSF, and now loads more power still!
Failed Bosch MAF's are VERY VERY common thing on all vehicles with them fitted of this era.
Even if you also have other issues, it's 99% certain the MAF is under reading the airflow.
If you have VCDS, the reading at full throttle acceleration should be more than 800mg/st, 400-500 and it's definately shot, but not enough to throw a fault code.
 

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Discussion Starter #4
Thanks for all the replys
I tried the MAF that day, it didn't make any difference really but today I had a thought after I got back home from Das Auto.
Andy had said the MAF was functioning but the actual air flow was higher than the reading.
Yup that old chestnut..
My input pipe onto my turbo is looser than a loose thing..
I have to do THIS process tomorrow.

Also at the time of this post my timing was so off it wasn't on the measurable scale..
 
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