[phils95cobra]

Hello,

Over the past week, I have had this new issue with my 01 Passat 1.8t AUG. When I go to start it after it has been sitting, let's say, over night or for more than 5-6 hours, it cranks, and at likes it has started, but then dies. On the second attempt, it always starts right up. I have not checked for codes yet, and I get this feeling that I won't get any, but will have to bring it to autozone to check.

It runs fine after that! Still gets awesome gas mileage, no sputtering, missing, etc, has good power...

Any ideas?

thanks,

 

[ylwagon]

Either the coolant temp sensor is bad, or there is an air leak, these are common reasons for hard starting. There's others things that can cause that, but I would start with a new CTS and inspect for cracks/hose breaks, broken check valves, etc.

 

[John_E]

Either the coolant temp sensor is bad, or there is an air leak, these are common reasons for hard starting. There's others things that can cause that, but I would start with a new CTS and inspect for cracks/hose breaks, broken check valves, etc.

Very true. My problem (also AUG, but probably applies to most 1.8T versions) was a bad MAF sensor, both the original and the first replacement I tried. VCDS pointed this out straight away -- extreme lean trim with one, extreme rich with the other, within 0.5% of neutral with the third (good) one.

 

[phils95cobra]

Thank you for the replies. I will check the vacuum system this weekend. I was just working on it a couple of weeks ago, replacing the crankcase vent elbow and PCV "T" adapter. Both were totally shot and venting crankcase into the engine bay, not to mention the PCV sucking wind from being completely exposed to the atmosphere.

I have a VCDS USB adapter cable, but I think it is fried because I cannot use it to scan anymore. Is there a reliable vendor for these adapter cables?

Thanks everyone,
Phil