[philly88]

On my 08 CTS last time I got an oil change it the car sounded like it wanted to start but wouldn't. It took about 6 attempts to get it to work. The next three time I've fueled up the same thing happens. And this isn't on an empty tank, I never let it run very low. After fueling it doesn't want to start. Will take 3 or 4 tries and a pump of the gas pedal to get it running.
Once it starts it seems that it doesn't do this again until the next fuel up. I think maybe its the evaporator purge valve? The check engine light is on as well.

 

[CaddyFred]

The DTC (diagnostic trouble code) will tell you exactly what is wrong 9 out of 10 times. I strongly suggest that you invest in a OBD2 code reader or have someone who has one read the DTC causing the CEL (check engine light). Many auto parts stores will read the DTC for free. If you have a smart phone there are free and very inexpensive apps that will allow you to read and clear the DTCs using a cheap bluetooth OBD2 adapter.

Examples:

Torque for android
Dashcommand for ios

https://smile.amazon.com/SAVFY-Blue...d=1555779612&s=automotive&sr=1-30-spons&psc=1


... or we could guess, throw darts at a list of possible causes, etc.

 

[Long]

... or we could guess, throw darts at a list of possible causes, etc.

This sounds like way more fun. Couple more beers and I'll have some very interesting causes.

Seriously...get the codes read.

 

[CaddyFred]

This sounds like way more fun. Couple more beers and I'll have some very interesting causes.

Seriously...get the codes read.

I'll start!

My guess is that it has something to do with the CEL.

 

[Long]

I'll start!

My guess is that it has something to do with the CEL.

Get out.
Could it be that obvious?

 

[CaddyFred]

Hopefully. I've always had great success with OBDII DTCs pinpointing the problem, unlike OBDI where there would often be multiple DTCs and you had to guess which one was the actual cause.

 

[philly88]

I don't have a code reader, and after doing my web research I was pretty sure it was the purge valve. Aside from not wanting to start upon refueling it also started to buck a bit when trying to accelerate a bit hard.
Got the part on Amazon for $30. Took about 45 minutes to install. Fueled up, no miss-starts. give'er down the road, no bucking. All is great again.

 

[HurstGN]

I thought the purge valve involved dropping the tank....I must be mistaken.

 

[Long]

I thought the purge valve involved dropping the tank....I must be mistaken.

You are thinking of the vent valve solenoid.
Purge valves are usually located under the hood.

 

[HurstGN]

You are thinking of the vent valve solenoid.
Purge valves are usually located under the hood.

Thank you for the correction. I knew there was a valve that I didn't ever want to have to deal with.

 

[Long]

Thank you for the correction. I knew there was a valve that I didn't ever want to have to deal with.

That's the trade-in valve.

 

[silversport]

ahhh...the morning coffee meets the sinus cavity ...good one Long

Bill

 

[HurstGN]

My Bonneville went due to the Trade-In Light coming on.

 

[Padgett]

Never saw a ODB-II dongle with an on-off switch before, not something you can see easily. Most use less power than the clock when not in use so just leave in place.

It is interesting that kids are computer-literate yet the OBD in cars seems to baffle them. Maybe if they had videos. Mine displays on the touchscreen.