hard starting
11-01-2010, 01:23 PM
#2
Audi Forum - Posts like a Q7
Join Date: Nov 2008
Location: Regina, SK
Posts: 725
Re: hard starting
If you want to do your own maintenance, you should have ready access to a VAG-COM. When something is up with my car, the first thing I do is scan it for codes.
Since it's always on Mondays, is it after it has been sitting all weekend? If it seems to happen after the car has been sitting for extended periods of time, it could be either your battery not holding a charge, or that there is a small air leak in your fuel system, causing it to lose its prime.
Since it's so simple, check the battery with a multimeter first. Ensure that you've got the following:
>=12.6V with the engine off, after the battery has been sitting for a few days.
>9V after while cranking the car, after the battery has been sitting for a few days.
If the battery checks out, I'd start looking at the hoses and connections in the fuel system, for possible air and/or fuel leaks.
Since it's always on Mondays, is it after it has been sitting all weekend? If it seems to happen after the car has been sitting for extended periods of time, it could be either your battery not holding a charge, or that there is a small air leak in your fuel system, causing it to lose its prime.
Since it's so simple, check the battery with a multimeter first. Ensure that you've got the following:
>=12.6V with the engine off, after the battery has been sitting for a few days.
>9V after while cranking the car, after the battery has been sitting for a few days.
If the battery checks out, I'd start looking at the hoses and connections in the fuel system, for possible air and/or fuel leaks.
11-01-2010, 05:23 PM
#3
Audi Forum - Posts like an A1
Join Date: Jul 2010
Location: Québec city
Posts: 14
Re: hard starting
change your crank sensor... it turn on the fuel pump when it see the motor turning.. you can surely only clean the sensor too, the face is a kind of magnet who come dirty...
11-01-2010, 08:48 PM
#4
Audi Forum - Posts like a Q7
Join Date: Nov 2008
Location: Regina, SK
Posts: 725
Re: hard starting
Why would his crank sensor only not work properly on Mondays? In any case, just telling someone to shotgun parts into their car isn't the ideal way to repair a vehicle. I'm not saying that his crank sensor isn't the issue, but let's put some thought into it...
12-26-2010, 04:34 PM
#7
Audi Forum - Posts like an HORCH
Join Date: Dec 2009
Location: Burlington, Ontario
Posts: 2,719
12-28-2010, 02:31 PM
#8
Audi Forum - Posts like an A1
Join Date: Aug 2008
Location: Waterloo
Posts: 19
Re: hard starting
I have the same problem with my 98 A4 and I've been trying to find a solution everywhere, but still unsuccessful. I've heard people say it might be caused because you loosing fuel pressure and if that's the case you have to "live with it"..... what kind of BS is that??? But in my case, not only my car is hard to start in the morning, when it does start my idling is all messed up as well and it's only getting worst. In the beginning it would idle around 1600 but sometimes drop back to normal around 900, but for the past couple of days it constantly bouncing from 1800-2100 rms.
..... but i think (or I hope) if i solve the problem with cold starting, the other problem might be gone. or if not then at least I`ll have one less problem to worry about.
12-28-2010, 04:05 PM
#9
Audi Forum - Posts like an A5
Join Date: Oct 2010
Location: Republic of B.C.!
Posts: 382
Re: hard starting
By the sounds of it, we might have to start shotgunning parts in because this thread is dying.
I have the same problem with my 98 A4 and I've been trying to find a solution everywhere, but still unsuccessful. I've heard people say it might be caused because you loosing fuel pressure and if that's the case you have to "live with it"..... what kind of BS is that??? But in my case, not only my car is hard to start in the morning, when it does start my idling is all messed up as well and it's only getting worst. In the beginning it would idle around 1600 but sometimes drop back to normal around 900, but for the past couple of days it constantly bouncing from 1800-2100 rms. .....
but i think (or I hope) if i solve the problem with cold starting, the other problem might be gone. or if not then at least I`ll have one less problem to worry about.
I have the same problem with my 98 A4 and I've been trying to find a solution everywhere, but still unsuccessful. I've heard people say it might be caused because you loosing fuel pressure and if that's the case you have to "live with it"..... what kind of BS is that??? But in my case, not only my car is hard to start in the morning, when it does start my idling is all messed up as well and it's only getting worst. In the beginning it would idle around 1600 but sometimes drop back to normal around 900, but for the past couple of days it constantly bouncing from 1800-2100 rms.
..... but i think (or I hope) if i solve the problem with cold starting, the other problem might be gone. or if not then at least I`ll have one less problem to worry about.
Coil pack and fuel injectors! Replace them and you're good to go!
12-28-2010, 05:07 PM
#10
Audi Forum - Posts like an A4
Join Date: Nov 2007
Location: South of Heaven
Posts: 117
Re: hard starting
Cold starts are the hardest for the motor and if it only happens after the car has been sitting I would check the system, differential, and residual fuel pressure as a test. It never hurts to check the engine compression from time to time as well because a dead cylinder will make it harder to start. If your plugs or ignition system is not up to spec this can cause the problem as well so check those plugs and see what condition they are in. You may want to check the gap as well, many people will tell you they are pre-gapped but this is a load because they are gapped within a wide range and they are not always close. For performance the solid copper core plugs are the best but they don't last long and as you get to platinum's and iridium plugs they last longer but they don't dissipate heat as well which causes the gap to increase and they are designed for long life and not superior performance. On this note make sure the fuel filter has been replaced as well as the air filter. If you are using an oiled air filter make sure it is not over oiled and make sure the MAF is clean as this will get soaked in oil after a while. The MAF does a burn off as you turn the car off but this doesn't always clean everything.
Check the obvious as well, make sure the batter posts are clean, greased, and tight and that the charging system is making at least 13.5 volts. Check all of those little vacuum lines and make sure they are not failing and they are plugged in properly. Check that there are no intake leaks from the MAF to the throttle body because any leaks in there will cause the car to be hard starting. Old relays can cause this as well, I don't know about the Audi world but in the VW world the fuel pump relay and ECM power supply relays can start to degrade over time and this can cause a hard start. There is also the ignition switch, over time these can take too much current and this can cause the contacts to burn which can also lead to harder starting.
Ah yes, for hard starts there are lots of things that can either play a part in it or cause it so it can be very hard to track it down.
Check the obvious as well, make sure the batter posts are clean, greased, and tight and that the charging system is making at least 13.5 volts. Check all of those little vacuum lines and make sure they are not failing and they are plugged in properly. Check that there are no intake leaks from the MAF to the throttle body because any leaks in there will cause the car to be hard starting. Old relays can cause this as well, I don't know about the Audi world but in the VW world the fuel pump relay and ECM power supply relays can start to degrade over time and this can cause a hard start. There is also the ignition switch, over time these can take too much current and this can cause the contacts to burn which can also lead to harder starting.
Ah yes, for hard starts there are lots of things that can either play a part in it or cause it so it can be very hard to track it down.
