Bad acceleration in low rpm

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KGoranov1999
Newbie
Posts: 1
Joined: Wed Oct 16, 2019 10:44 pm

Bad acceleration in low rpm

Post by KGoranov1999 »

Hello! I have 406 2.0HDI 110 from 1999. The problem with bad acceleration in low rpm is confusing me . I think the problem is with the turbocharer since sometimes it doesn't turn on on time, for example when I'm on 3rd gear the turbo starts after 3000rpm . I bought the car recently and before i bought it I drove my friend's 406 with the same engine and compared to mine it's flying .
I have only changed the air filter .
P.S The exhaust is broken through ,can this influence the car's performance too?
Gilly
1.8 8v
Posts: 22
Joined: Sat May 25, 2019 1:05 pm

Re: Bad acceleration in low rpm

Post by Gilly »

Hi there,

I would start at the air flow meter. These can give problems and lead the car to act like yours.
Unplug the air flow meter and take it for a drive, if this cures the issue you will simply need a new one.
Try to get an OEM as aftermarket cheap meters can just be as bad.

Hope this helps!!
2001 HDI 90bhp - current daily
GingerMagic
3.0 24v
Posts: 3569
Joined: Fri Apr 06, 2012 9:02 pm
Location: Bournemouth

Re: Bad acceleration in low rpm

Post by GingerMagic »

Agreed - the air flow sensor ( sometimes referred to as a MAF sensor ) gets dirty over time and gives duff information - unplugging it makes the ECU resort to a default setting....
If your car improves then as already suggested, try to find a genuine one ( Siemens VDO) from a local motor factors - check online for discount codes.

If there is no improvement then I would next consider a vacuum leak or a boost leak.
Check the bottom of the intercooler for bubbles when you rev the engine - it's normally a bit oily down there so easy to see bubbles - and the big pipe from the top of the intercooler should expand and go hard :wink: when revved

If this looks okay then next check the small black pipes that come from the 2 solenoids on the driver's side of the bulkhead. Follow these with your fingers checking for splits and damaged ends.
Basically a vacuum leak will starve the turbo momentarily until it gets enough revs/vacuum to close the wastegate and allow boost..!!

Good luck with it, please let us know how you get on.
2003 2.2hdi estate - mine
1998 Volvo 940 auto estate - also mine
2019 Citroen C3 something - the wife's
PP2000 user, can help with faults / diagnostics in the Bournemouth area.
PeterN
3.0 24v
Posts: 1673
Joined: Sun Mar 04, 2012 6:04 pm
Location: Charmouth, Dorset

Re: Bad acceleration in low rpm

Post by PeterN »

Have your brakes deteriorated at all? The vacuum pump can fail and provide to little to control the turbo properly.

Peter
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