TheSpeedDemon

Ok so my car sat in the garage for a little over a week from the last time I drove it. I had no problems when I drove it then.

But now I go out and start it, yes it starts, but it will not idle at all. It is acting like it is mis-firing, very rough idle. If I do not touch the gas it will die. If I give it some gas the rpm's go up and the 'roughness' goes away. But then after letting of the gas it idles rough again and dies.

Not sure where to begin to look.

So I am reaching out to my Rennlist buddies to see if you have an idea as to what is going on and what I need to do next? I do not want to take it to a shop if not needed.

Doug Donsbach

What does the code reader tell you?

TheSpeedDemon

Doug, the code reader is on my list to get although I am not sure what model to get.

Would there be any lights on my dash when this is happening like a CEL or something?

gota911

Steven, check to see if you have a loose vacuum hose. This can cause the car not to idle or to idle very roughly.

Doug Donsbach

Any code reader is better than none at all, but it would be nice to have something that displays live data. Or, if you only do diagnostics on your 996, get the Durametric stuff.

You can have codes without having a CEL. If a quick look doesn't show anything obvious (connector dislodged, vacuum line or intake plumbing issue, etc.), the code reader is the next step.

IIRC, you recently had the throttle body off for cleaning. Anything you touched while doing that would be a good place to start.

TheSpeedDemon

Well I used the light in the engine compartment and a torch (flashlight) and looked around and everything looks OK but then of course I am not sure what vacuum lines are where.

TheSpeedDemon

Yep I looked around the throttle body but did not see anything. Plus that was a little while ago now that I had it off and I have driven it several times since then with no issues.

I would like to get a schematic of vacuum lines for my car so I can check everyone of them.

Since I do not have access to a code reader currently and would like to diagnose the problem ASAP since it is starting to worry me, any advice at this moment in trying to figure out why the car ran good one minute and now it does not, is greatly appreciated.

If you can tell in my tone of the messages I am a little concerned here since I don't understand why this would happen, plus it has been a very bad week for me in all areas of my life and this is not helping. I was planning on taking a nice drive in the car to take my mind of things but not now.

Chads996

Could be a couple various things. Here's some to consider:

1. MAF sensor bad? Try cleaning it with some brake cleaner.
2. Vacuum lines?
3. How's the mileage on the car? Spark plugs?
4. Go pick up a bottle of Techron (good to do at every oil change) to clean the injectors.

Most Auto Parts stores have an OBDII code reader. See if you can get it checked out. My bet - the MAF. Classic symptom is very rough idle.

Doug Donsbach

Since the car has been sitting for a week, fuel contamination (finally settling in the tank) might also be a cause. Did you add fuel to the tank during your last drive?

Any vacuum leak - oil filler tube, loose hose clamps on any of the intake plumbing, anything that would leak air into the intake without metering it through the MAF - should be considered.

Chads996

+1 On everything. Start from what costs less to most.

C.

4-large

SD
In my days of V8 I would spray (carb cleaner & a another product???) on the carb to see if the rpm would change...If it did not change than it had no vacuum leaks, Not a heavy spry, but a fast mist and have somebody hold the rpm constant
Have you tried to run the car and see if it would just clean itself up?

TheSpeedDemon

Thanks Doug and Chad.

So if the gas is bad what can I do to solve that? I cannot remember if I added fuel to it either the last time I drove it.

I am about to have dinner and may look at it afterwards but I doubt it, too cold and dark in the garage now.

I will keep you posted.

Anything else you can think of please let me know.

Thanks

TheSpeedDemon

Unfortunately it dies before I can get around to the back of the car to grab the accelerator to keep it running.

dresler

I'm not sure if you got Chad's meaning- but most autoparts stores will let you borrow the OBD reader without buying it (or pay a small fee)

Chads996

There is a product that help evaporate water if present in the tank. I cannot remember what the name is.

Also - go get some fresh fuel and add it to the tank (if possible).

And yes...thank you dresler, that is what I meant. AutoZone has them and so does Pep Boys.

Good luck.

C.