engine problem a4 19 tdi 1998

[stevestout]

vin no WAUZZZ8DZWA131893 please can anyone help me this car will not start without a push . once startetd if the accelerator pedal is releasd the engine will stop.while driving full power is ok but light acceleration / coasting the engine revs rise and fall irraticly.eeven when engine is warm it will not start with the starter motor which seems to spin fine [same as it always did].this problem has grown steadily from it taking a littlke longer to start with the key to now not starting at all.when driving if the car is allowed to coast and the revs fall below 1000 then if you press the accelerator pedal nothig happens [car continues to coast or slows down]if you change to a lower gear then it will accelerate.
the cam belt was replced recently by audi main dealer . since problem started i have replaced the air and fuel filter, glow plugs and added a injector cleaner to fuel .i am in southern spain now with no access to a dealer close by [150 miles] thanks for taking the time to read about my problem as i wanted to give as much info as possible . does anyone have any ideas what could be wrong

[Alan02]

Hi,as cam belt was renewed by main dealer i guess the pump timing (static and dynamic) `should` be ok.If this fault started a while after it was done,faults could be not reading fuel temp(top of fuel pump),weak signal on crank sensor etc.You dont mention a glow plug warning lamp either flashing or not flashing?this is a tell-tale fault lamp for the engine management,if it does flash,there is an electronic fault.without a diagnostic check,only suggest checking quality of fuel,no water in it,pump wiring connections,earths etc.and also crank sensor plug.hope you get sorted soon.

[stevestout]

thanks for the reply alan .i will try draining the fuel and replacing also could you tell me where i will find the crankshaft sensor and what ican do to check it also you mention aboute glow plug light flashing this does happen when i start the car on the hill outside my house but once it is running if you turn the key off and on it comes on very briefly then goes out and stays out.

[adamss24]

Get a diagnostic scan first, clear the old codes and see what else cames back. I would suspect engine timing might be out or there is air in the fuel and pump cannot prime itself. Does the fuel filter has a plastic non return valve on top ? If it does, these are known to fail and the pump is weak to self bleed when the fuel goes back into the tank. The easy way to bleed is by towing or bump start the engine as you allready know. The accelerator peddal is known for failing. There is no phisical connection on tdi between the pump and go pedal, there is a potentiometer wich gives position signal and the pump + ECU works out how much fuel to inject. If you are close to N. London i could have a look on your car. Regards, Chris- 077 899 12128.

[Alan02]

crank sensor will be in the area of the bell housing,low down on the engine side,where engine and box are bolted.You`ll see a plastic connector on it.You can only check the condition without the Diagnostic kit,but worth looking at.Also,have you checked to see if the fuel cut-off solenoid on the top-rear of the pump is energised with ignition on?This is known to be faulty at times.