last april we bought our teenage daughter a 1999 audi a4 in great condition. drove like a charm for a few months. she went to college in sept and when the car sits for a day or so has trouble starting in the am. it will turn over, tested battery and fully charged, but engine “labors” to start. doesn’t matter how far you press down the gas pedal, has no effect on the labored start. if you keep the key turned the laboring engine goes faster and faster and usually will turn over. once the car starts it starts perfectly all day. but after it sits overnight it will usually labor to start again the next am. took to mechanic who said it was a faulty fuel injector, replaced one and also spark plugs. car started great for a week and then one morning, same problem. help!!!
Audis of a certain age can become rather expensive to keep on the road. Nice car, just not cheap to keep.
Tell your daughter to try this:
In the morning, turn the key to ON and wait five seconds. Count slowly. Then turn the key to START. See if that makes any difference.
This procedure gives the fuel pump time to pressurize the system. If the check valve is leaking and the fuel system loses pressure overnight the engine will have a hard time starting.
Pressing the gas pedal should only be necessary if the engine is flooded, which it could be if the injectors are leaking.
But try the fuel pressure test first.
In the first place you don’t step on the gas pedal when starting .
thanks, i am going to try that tomorrow am. i’ll let you know what happens.
Other than agreeing with the other comments let me add this, and I hate to rain on your parade here.
If the car has not had a timing belt job in recent memory then this is something that needs to be done ASAP. Both engine applications are interference fit, which means if the belt snaps the engine will suffer some expensive to fix damage.
Just making you aware of this situation in case you may not be familiar with the process.
If someone said, or says, that it has been done then ask for receipts. Without receipts to prove it you must always assume the belt/tensioners/water pump need to be changed promptly.
I THINK you are describing a low charge on the battery. In a fuel injected vehicle your foot does not go near the gas pedal…not needed and not good to depress that…Your fuel injection system takes care of this for you.
A timing belt will not cause any of the issues you are seeing…It is good to know the state of the belt and whether it nees to be changed or not…but thats the extent of it…It either needs a new belt or it doesnt…this will not affect the starting of your vehicle or manifest its state to you with these symptoms.
In your description you state that it is LABORED…while turning the engine over…and then speed increases after you spin the engine a little bit…this is due to heat and friction. You are using the term turn over incorrectly in one instance and then properly the next…so I am getting a little confused.
I would first look at your battery terminals…in winter this is THE most common cause of starting issues BAR NONE! Make certain your batt terminals AND your battery cable clamps are CLEAN and greased…you can buy the little wire brush tool for this for 3 bucks or less…it has an internal and external wire brush to clean up your batt and clamps. DO THIS FIRST! It is cheap easy and almost always very affective.
The car starting properly after it has been run during the day is more evidence of the low battery issue. When the engine is hot it is easier to turn over and then start. I bet you have a low or weak battery…do the terminals first.
If you want to test my theory even further…Hook up another car to your Audi in the AM when you know or it is most likely to have this issue starting…Hook a jump up and then try to start it in the AM…if she turns over with more speed and doesnt labor to start…then you just proved out the low batt…dirty terminals are the most common cause…However dirty terminals can kill a new battery over time because the batt never gets charged properly because of corrosion. You have some tests to do…the jump test will reveal quite a lot in one fell swoop so Id try that asap.