997rs4.0

Just sent the car overseas for some hopefully fun days in Europe.

Picked up the car after container ride. (They drain the gas while in container)
Filled up with one tank of European 95 octane. Car ran fine. Second tank of gas threw a check engine light. Thought it was a cat sensor issue. So did the old trick of disconnecting the battery. Car sat for a week while I traveled for work.
Started it up yesterday and no check engine light but the car feels like it chokes itself. Doesn't die in idle but runs very poorly. As in can't drive it.
I've changed one of the fuel pumps in a previous 996gt3. That car still ran, so this is worse.
Anyone have any ideas?

997rs4.0

Oh,

There was no codes in the computer. Plugged it in yesterday. Really weird.

biglicks

wrong fuel, I always run my cars on 98?

AudiOn19s

No codes likely means fuel pump or that hose on the pump that commonly fails.

O2 or MAF issues almost always are accommodated by CEL

sp0da

When was the last time you changed the fuel filter? In my 6 years of ownership, I've found my car to be very sensitive to the condition of the fuel filter and just change it yearly now regardless of miles.

Might just be the crap gas we get here in CA...

996FLT6

Sounds like a bad batch of gas hopefully. God I hate troubleshooting when it's not that : (. Mike

Macster

What was the odometer reading when you dropped the car off vs when you picked the car up?

Did you check for pending error codes?

A very very long shot -- I only mention this because you can do it in just a minute and a half -- is the E-Gas needs to be calibrated.

This procedure should be documented in the owners manual. From memory from both my 2002 Boxster and 2003 996 Turbo: With the ignition in the off position and your foot off the gas pedal through the entire procedure turn the ignition to the on position. Do not crank the engine. Leave on for at least 60 seconds. (I use the in dash clock to time this.) After at least 60 seconds turn the ignition to off. Leave off for at least 10 seconds. The next time the engine is started the calibration is complete.

Absent any pending error codes, I'd have to agree with Mike that it is likely bad gas, that is gas with some water in it.

Years ago I had a pickup truck what while making a sharp turn the engine just quit like I turned off a switch. Investigated it and found some water in the fuel filter. The filter -- an inline job -- with translucent plastic so I could see the filter element and I spotted some drops of rusty water in the housing. (The truck had a steel gas tank.) I removed the filter from the fuel line and blew it out and reinstalled it and the engine started and ran just fine afterwards.

You'll have to get with a qualified shop there and probably have it eliminate other issues, like a bad fuel pump, or inadequate fuel supply or pressure, or something else. If it is "bad gas" then the shop should know how to deal with this.

biglicks

what about having drained the fuel for transport, some crap was picked up from the bottom of the tank and has made it into your fuel system?

997rs4.0

Thanks for all the answers,

Really hope its a simple fix. Cant remember when I last changed fuel filter.
No idea how they drain the gas out the gas tank before transport? Doubt its thru the refilling hole.
The strange thing is that the car ran great after I filled it up and drove 3h home from port. (In poring rain) Then after filling up the second time it started acting up.

Car is at the shop now.

Check list will be.

*New batch of gas
*Change fuel filter
*Check fuel hoses (if they emptied out the tank that way) Doubt it, not leaking gas anywhere
*Fuel pumps

997rs4.0

Sorry, did fill up with 98. Always run the Porsches on highest octane I can find.

AudiOn19s

Sounds like the right plan. For reference the line that commonly breaks is on the pump in the tank so you don't see any leaks it just causes loss of pressure.

oldskews4

Also check the variocam valve.

tgavem

Another option, by coincidence and unrelated, your coils got bad at this time.

Mine went, check engine light, cleared, drove fine for a little bit. Then started rough the next time, misfires. Drove slowly to shop. Diagnosed as bad coils.

997rs4.0

Would that throw a code?

Thanks, will check. Might be time for a change anyway.

oldskews4

I've seen it not throw a code.