maf sensor

[wazevan]

Hi all,
My car has been losing power and a bit sluggish so on Wed I added wynes injector cleaner tank.(Put whole bottle in half a tank,should have only put half bottle whoops)
On Friday car revs were going very high and car struggled to get going between 30mph and 50 mph.Revs were really high 4,500.
Took on motorway and manged to get up to 70+.Took it home and was still playing up.I disconnected the maf sensor with engine running and no difference (shouls something happen to engine revs)nsor off did not notice any difference.Took car to 70 and then dropped gears down to 4th.
Next day car is running fine ,ive done 200 miles ,lanes,hils and motorway car ok.
Should I buy maf sensor or was it because maybe the cleaner caught just cleaned some crap out.

[johnnyroper]

The maf sensor is a fairly expensive part change on a whim,best bet is a vcds scan for fault codes and check of measuring blocks to see what maf signal is doing. Typically on a vw diesel if it's faulty when you disconnect it will run ok as it reverts to pre defined reading.

Usual suspects for things like that would be sticky turbo vanes but cannot really diagnose anything on these without a scan and check of what sensors are doing etc.

[actionvin]

I had a similar problem and replacing the MAF sensor had not effect on it. I bought the gear to do a Mr. Muscle clean thinking it must be the turbo. I checked the turbo actuator, couldn't move it with my finger but went fine with a spanner attached smooth action and return. I did a full service (Oil and all filters) fuel filter was black inside changed it car runs like new now.

[johnnyroper]

Black inside fuel filter is indicative of either failed injector seals or tandem pump.
Basically if either fail it can cause engine oil to leak back through fuel return.

[actionvin]

Ok so I was a bit premature with the 'Drives like new' comment !
Just come back from a 1000 mile holiday drive the Galaxy performed faultlessly on the flat and hills. But when it came to some of the moorland hills in Devon  the engine 'hum' sounded more like a pulse but didn't splutter or misfire this was promptly followed with a flat spot and limp mode until turned off, do you think the Injector seals or tandem pump may be the problem bearing in mind my 'black' fuel filter ?
I don't have and software for the computer as i run a MAC and the software doesn't work with it (I think.. as I'm a complete computer f@Ã,£%wit) 

[johnnyroper]

I seriously doubt it would go limp mode due to tandem or injectors.
As you were on hills and demanding more boost I would say it was due to overboost.
You really need to check fault codes first.

The black in fuel filter could be either and is seperate fault in my opinion.