1995 Audi A4 TDI 90BHP Smoking And Power Loss

[cstevens99]

Hi,

I'm currently suffering from loss of power and smoking with my Audi A4. I did have a tune box fitted but have now removed it. The car is fine around town, but when accelerating from 70 - 80mph there is a power loss and smoke is produced. I read in an earlier post a similar problem and the guys replying recommended a replacement MFU.

Any suggestions would be great as it's driving me nuts and killing the planet!

Chris

[Dave Avant]

I would look at changing the MAF (inlet airflow sensor). Try unplugging it and test driving. If it makes no difference then it usually denotes a dud MAF. Mafs can be cleaned with electrical cleaner and blow dry with compressed air. But it may be passed that.

Or could be something simple like a blocked airfilter. I've seen a diesel filter that had been through a puddle and got it soggy and was also full of leaves.

[cstevens99]

Drove the car last night with the MAF disconnected and basically it drove without the turbo working. I then reconnected the MAF and instantly the car was ok again. Tested it again this morning coming into work and it's back to it's normal tricks - flat spots and smoking.

Could this be a MAF?

[adamss24]

Run a bottle of injector cleaner trough the tank. How many miles on the clock, are the nozzles original ? Did you replace the filters(air and diesel) ? If the car is high milleage, i would remove the turbo, the inlet manifold and the EGR valve, and clean them as there will be a lot of carbon build up ! Another thing to check on high milleage cars is the catalyst, as it plugs off if the engine gets overfilled with oil ! Also check the temp sensors as when duff, the ECU its confused and uses default values(limp mode) to protect engine. Ask someone with a Vag-com to scan the modules for you and post the codes(if any !) on the forum.

[cstevens99]

Hi,

I have run injector cleaner through with no success. The car has 138,000 miles on the clock. The air filter has been replaced, but not diesel.

I have read about cleaning the inlet manifold as it can become blocked with carbon/soot. How easy is this to do?

[markf497]

i had a similiar problem it was the thick rubber hose from the turbo to the fixed plastic pipe that goes round the top of the engine it had a hole in it.