cant figure it out! :(

[Shi-Fu JaY]

so I've used the search function to find answers about why my 2002 Audi A4 1.8t Quattro tip is so hard to start when its been sitting for couple hours.

I replaced the fuel filter, changed my oil, new spark plugs about 3K miles ago, and cleaned the air filter. nothing has helped.

the car is still hard to start. in the morning, it'll just crank. I take the key out of the ignition, and replace it back in for a second start, and the car will than start.

I go to work (4 hour shift) when I get out, the car will crank for a bit, then start to sputter/ very low idle for about 2 seconds, after that it idles like it should.

anything else I should check for? tips, hints?

oh and there isnt any whining noise when I put the key on the "ON" position
BUT I hear a weird knocking noise as I am cranking the car. noise seems to be comming from the rear passenger side were the fuel filter is.....but I just replaced it.


UPDATE: I got the car scanned with VAG-COM at AUTOBAHN EXOTICS
First off, I want to give a HUGE thanks to Nick at Autobahn Exotics in Chino, CA for scanning my car to see whats wrong with it.
So I got couple codes that cant possibly contribute to my starting problem.

but I did get only two that might be my problem
17522 - Oxygen (Lambda) Sensor; B1 S2: Internal Resistance too High
P1114 - 008 - Implausible Signal - Intermittent

18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 002 - Lower Limit Exceeded - Intermittent

could a bad oxygen sensor cause the car to not start on the first attempt?

and what is P1602?
P1602 - 002 - Lower Limit Exceeded - Intermittent

[FireWire]

fuel pump? normally a fuel pump makes a whirring noise while priming for ignition.

if its sputtering that's usually the culprit. that's just my take.

*off topic (sorry i just had to ask) are you still selling the vinyl sheets for roofs? I tried pm'ing you about it

[B6Lovin]

so I've used the search function to find answers about why my 2002 Audi A4 1.8t Quattro tip is so hard to start when its been sitting for couple hours.

I replaced the fuel filter, changed my oil, new spark plugs about 3K miles ago, and cleaned the air filter. nothing has helped.

the car is still hard to start. in the morning, it'll just crank. I take the key out of the ignition, and replace it back in for a second start, and the car will than start.

I go to work (4 hour shift) when I get out, the car will crank for a bit, then start to sputter/ very low idle for about 2 seconds, after that it idles like it should.

anything else I should check for? tips, hints?

oh and there isnt any whining noise when I put the key on the "ON" position
BUT I hear a weird knocking noise as I am cranking the car. noise seems to be comming from the rear passenger side were the fuel filter is.....but I just replaced it.

congrats, that's where your fuel pump is too.

[Shi-Fu JaY]

so its indeed my fuel pump?
should I check for cheaper potential problems, before going out to get a fuel pump?

[B6Lovin]

so its indeed my fuel pump?
should I check for cheaper potential problems, before going out to get a fuel pump?

not neccesarily... but you could just test the pump. pop your hood and relieve all the fuel pressue in your rail (there's a little schrader valve on the back side of it.. press it in with a small screwdriver or pen and then drain the gas into a small cup or w/e you have on hand)

after that, get in your car and turn the key to the accessory position and let it sit for a few seconds. turn the key to off, get out, and repeat the first step again. if fuel comes out like before - that means your pump is priming the system properly. if not much or none comes out either your pump is probably dying/dead.

[B6Lovin]

btw, scan the car and see if oyu have any lean codes. if you do that's also a sign you're not getting enough fuel... points right back to the pump if everything else is good.

if you test the pump and it's working i'd look at your injectors next. one or more could be sticking shut when cold, though that's uncommon if not unheard of with our cars

[martini]

almost sounds like you are just losing fuel pressure at the rail...

[grjopo]

I had similar problems before i upgraded my fuel pump. If i tried to crank it over strait away it would struggle. All i did was turn it to on before cranking it over for 5-10 seconds, and I never had problems.

[Shi-Fu JaY]

almost sounds like you are just losing fuel pressure at the rail...

what would cause this? Im looking into every possibility!
and you guys have been great so far.

So I took my battery in for testing and they said it above normal.

After not driving the car for about 12 hours, I pushed in the valve at the end of the fuel rail, and it only spit out a drop of fuel.......Is this normal after leaving the car for 12 hours?

I proceeded to put the key in the "ON" position for about 5 seconds to prime the fuel. got out the car, and pushed in the valve. This time fuel was streaming out alot

So my fuel pump is still doing its job right?

could my starting problem be coming from something else besides the fuel delivery components?
Could it be the Fuel pump relay?
could it be the coil packs?
or could it be the ECU?

man im lost :(

[chadb2434]

Maybe some kind of fuel system flush?

[Shi-Fu JaY]

UPDATE: I got the car scanned with VAG-COM at AUTOBAHN EXOTICS
First off, I want to give a HUGE thanks to Nick at Autobahn Exotics in Chino, CA for scanning my car to see whats wrong with it.
So I got couple codes that cant possibly contribute to my starting problem.

but I did get only two that might be my problem
17522 - Oxygen (Lambda) Sensor; B1 S2: Internal Resistance too High
P1114 - 008 - Implausible Signal - Intermittent

18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 002 - Lower Limit Exceeded - Intermittent

could a bad oxygen sensor cause the car to not start on the first attempt?

and what is P1602?
P1602 - 002 - Lower Limit Exceeded - Intermittent

[diagnosticator]

Yeah, test the residual fuel pressure. It must be at least the minimum and hold that for the minimum specified time.
See the Bentley manual.

[Shi-Fu JaY]

Yeah, test the residual fuel pressure. It must be at least the minimum and hold that for the minimum specified time.
See the Bentley manual.

what is residual fuel pressure?
and how can I test it?

so a bad oxygen sensor CAN indeed cause the car to struggle on start up?

[diagnosticator]

what is residual fuel pressure?
and how can I test it?

so a bad oxygen sensor CAN indeed cause the car to struggle on start up?

The O2 sensor is not active on engine startup, because the sensor is not enabled until the sensor heats up above the required minimum operating temperature. Therefore, the ECU is in "open loop" control of fuel mixtures at startup, and does not depend on the O2 sensor.
Residual fuel pressure, is the fuel pressure at the injectors, when the car is turned OFF. The fuel pressure with the pump running and the residual fuel pressure must be within spec, or starting problems will occur similar to the symptoms you described. To test, a fuel pressure test gage is connected to the test connection at the fuel rail. See Bentley manual.

http://www.ebahn.com

[diagnosticator]

UPDATE: I got the car scanned with VAG-COM at AUTOBAHN EXOTICS
First off, I want to give a HUGE thanks to Nick at Autobahn Exotics in Chino, CA for scanning my car to see whats wrong with it.
So I got couple codes that cant possibly contribute to my starting problem.

but I did get only two that might be my problem
17522 - Oxygen (Lambda) Sensor; B1 S2: Internal Resistance too High
P1114 - 008 - Implausible Signal - Intermittent

18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 002 - Lower Limit Exceeded - Intermittent

could a bad oxygen sensor cause the car to not start on the first attempt?

and what is P1602?
P1602 - 002 - Lower Limit Exceeded - Intermittent

As explained before, the O2 sensor is not involved with the hard starting problem.

Intermittent faults are not "hard" faults, and in this context, means that the fault did not actually exist as an active fault when the scan was performed.

"18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 002 - Lower Limit Exceeded - Intermittent"

The information within the quotes above is the same single DTC record. The "18010" is the VAG proprietry code, the P1602 is the generic code number, both for the same fault recorded.

The P1602/18010 DTC is usually caused by disconnecting the battery.

Clear the fault codes and see if any of them reoccur right away. If they don't, don't worry about them, as they aren't occuring now.

BTW, the fuel pressure is not monitored by the OBDII ECU diagnostics, so there won't be any fault codes if the fuel pressure is not correct.

[tatarin]

As explained before, the O2 sensor is not involved with the hard starting problem.

Intermittent faults are not "hard" faults, and in this context, means that the fault did not actually exist as an active fault when the scan was performed.

"18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 002 - Lower Limit Exceeded - Intermittent"

The information within the quotes above is the same single DTC record. The "18010" is the VAG proprietry code, the P1602 is the generic code number, both for the same fault recorded.

The P1602/18010 DTC is usually caused by disconnecting the battery.

Clear the fault codes and see if any of them reoccur right away. If they don't, don't worry about them, as they aren't occuring now.

BTW, the fuel pressure is not monitored by the OBDII ECU diagnostics, so there won't be any fault codes if the fuel pressure is not correct.

For some reason my car is throwing a code now same as above " b2s2 resistance too high. intermittent" and also after clearing it i would some time show "b2s2 no activity....." this is a new o2 sensor with a connector not the generic ones...that i got, replaced it last weekend. no codes for like 4 days and now its daily. any ideas guys?