misfire/hesitation A160 1999

[chipsraff]

hi,have recently purchased a mercedes A160 avantgarde 1999.needed power pack to start vehicle and upon starting it idles eratically.on depressing accelerator pedal whilst stationary seems to misfire and upon driving off seems to misfire,hesitate and hold back whilst picking up speed.not so bad when finally reaching 5th gear although if applying more power holds back again.also feels like its going to cut out when pulling up to junctions.no warning lights displayed on instrument cluster while driving it.have now fitted replacement battery and just in case have fitted a set of new plugs.no difference noticeable to idling.i now have bas/esp warning light and abs warning light displayed on dash possibly because of battery change without driving???? Anyone with any ideas about hesitation and or fault warning lights please help before i have to spend a fortune getting diagnosis from local mercedes dealer.many thanks chipsraff

 

[wemorgan]

A few very wild guesses from me:
Throttle body
HT leads
MAS

Sounds like you need the warning lights reset and the fault codes read from a STAR machine. Good luck.

 

[chipsraff]

having vehicle star tested in next few days will update you.cheers

 

[Dieselman]

I'd say MAS as well. They are V expensive but BBA Reman offer an exchange service.

The symptoms do fit a weak spark though, but probably the MAS.

 

[chipsraff]

had star test done today and came up with no faults found but have been told could still be coil pack.seems to run a little better whilst engine cold and as warms up misfire and hesitation gets worse.

 

[jaymanek]

MAF sensor or throttle body.

Who did the Star test, you have to know what you are looking for.

 

[chipsraff]

local garage with star tester did diagnosis.whats the difference between maf sensor and mas and i take it throttle body in line with air intake pipe

 

[jaymanek]

throttle body sits just under the MAF/ECU and sometimes causes problems.

MAF & MAS same thing.