Sigh....what is it this time. Car turns but won't start

[audi_nightrider]

So my car left me stranded at work last Friday.

Car started with no problem first thing in the morning. Car sounds very good and was warmed up properly. Drove to work, car pulls really good and boosting well. No weird sound and was driving smoothly....Even let it cool down properly when I get to work.

Right after work, car was parked outside the whole day and when I tried starting it...it turns but wont start. Keep on trying to do it, hearing my car backiring? I can smell the gas so def. it has something to do with spark?

Vag-com the car and no engine codes...

A little background, I changed the 02 sensor with a brand new one and also installed new plugs gapped .042 2 or 3 days before. .042 coz I'm using the red 2.0 coilpacks with billet spacers.

TIA! Hope my post is clear.

I did some diagnostics from the other threads I've read and no luck....i.e. unplugging ABS plug, checking the fuse and etc...

[csosnowski]

Crankshaft position sensor.

[LINDW4LL]

Yeah, a likely possibility- OP, do RPMs show while cranking?

[MurkyRivers_A4]

Could very well be CPS but when mine went out I had the EPC light on as well as the ESP (traction) light. It did not result in a CEL either.

My buddy, and not saying this to scare you, had the same issue with his car. It sounded just like the CPS and I told him to change that as its more than likely the problem. He had it towed home by AAA, we replaced the CPS and still wouldnt start. Eventually decided to check the mechanical timing and the timing gear on the crankshaft had broken the dowel pins and rotated freely of the crank shaft.

No internal engine damage as it didnt happen while he was driving, only when he attempted to start the car.

[audi_nightrider]

hmmm...worth to check the CPS....just changed it less than 1k miles ago though

edit: NVM thinking about Camshaft sensor LOL

[MurkyRivers_A4]

hmmm...worth to check the CPS....just changed it less than 1k miles ago though

edit: NVM thinking about Camshaft sensor LOL

Checking mechanical timing is fairly easy as well. Line up the crank shaft pulley mark, check the camshaft pulley mark. If both are on point then its not that.

When my CRANK position sensor went out, I was having starting issues and the EPC light would come on.

[itsmatt33]

Checking mechanical timing is fairly easy as well. Line up the crank shaft pulley mark, check the camshaft pulley mark. If both are on point then its not that.

When my CRANK position sensor went out, I was having starting issues and the EPC light would come on.

sounds like my crank position sensor issue a couple years ago

[MurkyRivers_A4]

I obviously need to hang out down in the valley more often. Both of you guys are from Cali, and relatively close, but I never see anyone up here in the desert!

[old guy]

CPS is definately a possibility. So is a (shudder) bad timing belt.

You mentioned that you had recently replaced your spark plugs. It's possible that you have some heat damaged wires in the coil pack harness that have shorted. You also stated that you checked your fuses but it's worth going back and rechecking your engine management fuses 29, 32, 34 and 43.

Good luck!

[audi_nightrider]

Crankshaft position sensor.

Could very well be CPS but when mine went out I had the EPC light on as well as the ESP (traction) light. It did not result in a CEL either.

My buddy, and not saying this to scare you, had the same issue with his car. It sounded just like the CPS and I told him to change that as its more than likely the problem. He had it towed home by AAA, we replaced the CPS and still wouldnt start. Eventually decided to check the mechanical timing and the timing gear on the crankshaft had broken the dowel pins and rotated freely of the crank shaft.

No internal engine damage as it didnt happen while he was driving, only when he attempted to start the car.

CPS is definately a possibility. So is a (shudder) bad timing belt.

You mentioned that you had recently replaced your spark plugs. It's possible that you have some heat damaged wires in the coil pack harness that have shorted. You also stated that you checked your fuses but it's worth going back and rechecking your engine management fuses 29, 32, 34 and 43.

Good luck!

Thank you all! Sorry if I forgot to quote anyone lol.

So it def is the Crankshaft Position Sensor.

I hate when something like this happened...no symptoms or anything at all. my vag-com didn't even see any fault codes.

If we only have a list of this little things that we're supposed to change at a certain age/mileage.

Well thanks again!

[audi_nightrider]

Could very well be CPS but when mine went out I had the EPC light on as well as the ESP (traction) light. It did not result in a CEL either.

My buddy, and not saying this to scare you, had the same issue with his car. It sounded just like the CPS and I told him to change that as its more than likely the problem. He had it towed home by AAA, we replaced the CPS and still wouldnt start. Eventually decided to check the mechanical timing and the timing gear on the crankshaft had broken the dowel pins and rotated freely of the crank shaft.

No internal engine damage as it didnt happen while he was driving, only when he attempted to start the car.

Thank god it wasn't mechanical or else I would've burned the place where I got my timing belt done. If only knew all along how easy it is to do my timing belt, I wouldve done it by myself.

[audi_nightrider]

NVM...

I spoke too soon. Started the car with no problem and drove my car to work today, it was smooth and didnt feel like anything is wrong. Right after work.....my car starts but it shakes then turns off by itself, flashing cel but goes away. Fortunately there's a shop nearby and when they scan it, it shows misfire 3 and 4. Erased it the frst time and re-read it and nothing is popping up anymore.

Car can be driven if I apply gas and clutch. It turns off seconds later when I let go of gas and clutch.

When it rains it pours -.-

[itsmatt33]

check coils and plugs?

[MurkyRivers_A4]

How many miles on it and when's the last time the timing belt was changed

[audi_nightrider]

check coils and plugs?

yah coils are good man...removed #3 and #4 but it didnt change and still dies. Plugs were changed less than 500 miles ago, gapped .042 coz of the 2.0 red coils.

How many miles on it and when's the last time the timing belt was changed

Car is sitting on 148k miles.
Timing belt changed approx. 1,000 miles ago.

At first, got the whole TB components replaced when the tensioner prematurely went bad only after 35,000 miles.

Brought it back to the same shop when the water pump's o-ring was already leaking only after 1,000 miles.

I replaced my headgasket and replaced the head with AWM(got it machined and pressure tested, prior to installation).

Its been about 1,500 miles before all of this started happening.



UPDATE: Got to drive the car home, waited last night until there's no more traffic. It only dies on 1st and 2nd gear. I managed to keep it alive on 1st or 2nd gear if I pump both clutch and gas. On the freeway, it drives normally. A little sluggish when stepping on the gas when it hits below 3,000 rpm. When I got home, let it cooled down and it never died on its own

Sounds like a boost leak coz the rpm stays even when you let go of the gas.

[audi_nightrider]

Kind-of same symptoms when my MAP sensor was going out....

thoughts?

[audi_nightrider]

anyone?

[MurkyRivers_A4]

Are there any codes? Is you Check Engine light illuminated?

[old guy]

Did you ever figure this out? Have you tried unplugging your MAF sensor to see if it makes any difference? If it does that would be an indication of a boost/vacuum leak somewhere.