johnkk

Possibly. I was thinking that a check valve in the fuel pump assembly could be bad, or that I have a leaky injector. When I scanned the car (no codes) and read measuring blocks while the engine was running, I was getting a few missfires, only at cylinder 6. Maybe that's where the leaky injector is? I did check the fuel pressure regulator and it holds vacuum.

The fuel smell might not be at exhaust. I just thought I smelled some gas when i got out of the car after starting.

4Driver4 thinks crank position sensor could be it, but I would expect codes?

I'm going to throw a bottle of Techron in the car and see if that helps.

GTA_Driver

I had an intermittent cam position sensor failure. Couldn't start at times, at other times started up just fine.

johnkk

Mine always starts, just longer crank time when cold. Also, no codes. I just put a bottle of Techron in a 1/4 full tank and will see if that helps. Right now I'm guessing a leaky #6 injector.

Still could be the crank position/engine speed sensor. I'm trying to avoid throwing parts at it.

mithrilG60

When my CPS was on the way out my car showed the same symptoms, hard cranking and stumbling on ignition. Eventually it did completely die at which point the car would not start at all. There were no codes until it completely died. Depending on how the sensor fails you may not get any codes at all.

johnkk

Did yours run fine once started?

I'm getting no stumbling symptoms. Car runs fine once started. While Vag-com shows an occasional miss on cyl #6, I can't feel it.

Long crank time occurs only after car has sat for 20 minutes or more. If it sits for 5-10 minutes or less the car starts right up. Longer than 10 minutes and the cranking time incresases. First start in morning is about 5 seconds of cranking before she fires.

I checked for vacuum leaks yesterday with propane and no leaks were detected.

4Driver4 thought it was CPS, too. but I hate to throw parts at it. Maybe just keep driving it until symptoms get worse or more definitive?

johnkk

Car had to be flatbedded. Now I'm thinking the Crank Position Sensor was the problem after all. I'll throw one in. Wish I had the adapter to read residual fuel pressure on my gauge. Vagcom showed no injector pressure problems.

AudiThree

I have had this issue in the past, with no codes also. It turned out to be the fuel pump. The car eventually stalled one day and would not start up at all till i had the fuel pump replaced. Fuel pump could also be a possible culprit.

johnkk

After throwing parts at it, I think that's my problem, too. My past experience with fuel pump failure has always been seeing symptoms of rough running at speed, because of inadequate fuel pressure.

Once mine started, plenty of fuel. I guess pumps fail in different ways.

johnkk

new fuel pump in, fixed the problem. Chalk off CTS and CPS to preventative maintenance.