[Gaege]

I just completed a clutch replacement this month and replaced engine oil while I was down there.

Car's driving wonderfully but every once in awhile when idling it will turn off. It doesn't really stutter or stumble (maybe the tiniest bit). It'll be idling right below 1k (I don't know where normal idle is, so this could be an indicator of something?) and randomly it'll go down maybe...50rpm(visually, it's VERY slight. Audibly, it's not even noticeable) then turn off.

Could this be as simple as a accelerator pedal adjustment or should I be looking elsewhere?

It had a CEL for a while but I did the disconnect-battery-for-awhile-then-reconnect-and-run-some-drive-cycles method so I could get through emissions this morning (success!). Could the two issues be related? I cleared the CEL with the battery method yesterday at 5 so I'm assuming it's coming back sometime soon unless the vehicle magically healed itself.

 

[BobSaabit]

The most common reason for idle issues with a T5 is that the IAC needs to be cleaned.

FWIW, idle a little below 1000 is normal and a little variation would not concern me much. The stalling would.

 

[IOP9-3Guy]

Did you read the trouble code before you reset it? If not, the issue is still there.

If the car runs very rough after fillup, it's likely the evap purge valve. Otherwise the Idle Air Control seems likely.

 

[Gaege]

Did you read the trouble code before you reset it? If not, the issue is still there.

If the car runs very rough after fillup, it's likely the evap purge valve. Otherwise the Idle Air Control seems likely.

Code was P0300. And the car doesn't ever run rough. Always purrs like a kitten. Just decides to die sometimes when I'm idling.

 

[hapcj7]

How old are your spark plugs, which plugs are you using?..Whats the status with your DIC?.

 

[Gaege]

How old are your spark plugs, which plugs are you using?..Whats the status with your DIC?.

No idea on the spark plugs. I haven't pulled them yet. Was actually going to replace them today. I remember reading it requires some special NGK nonsense?

Last I check my "DIC" was working :cheesy:

But in all seriousness I haven't a clue on that either. I haven't removed it and wouldn't know how to test its correct operation. I was under the impression you just get a new one and hope that your last one WAS bad so you hadn't just dropped $180 for nothing. :roll:

 

[BobSaabit]

No NGK "nonsense", just get the stock NGK plugs

BCPR7ES or 6ES. 7 series for modded engines, 6 series for stock. Gap to .9mm. Don't use any other plugs as the DIC/ECU uses them to sense ignition and you want the stock NGK's.

 

[Gaege]

I'm finally getting around to pulling the IAC for cleaning tonight as well as replacing spark plugs. Hoping that'll get rid of the idle-stall issue.

If not, what are the next probable things to check? Would a weak battery and/or failing alternator possibly be to blame?

Down here in AZ the heat wreaks absolute havoc on batteries.

How about the DIC? Is there a way to determine whether it's faulty? If it is, could it be the culprit?

 

[ZiMMie]

Check you IAC

 

[Gaege]

Finally got around to cleaning the IAC. It was pretty gross in there.

The stalling at idle seems to not happen as frequently now, but still DOES happen. Is there anywhere I should be looking for vacuum issues?

 

[Gaege]

I had initially thought that maybe the stalling might be caused by low compression in one or more cylinders but it hasn't once stalled when bogging the engine down in first, even to as low as around 500 rpm.

It only stalls when my foot is completely off the gas pedal and only does it from time to time. Sometimes I can sit at idle with my foot off the gas pedal for 3 minutes or more and it won't stall. Other times it'll stall within fifteen seconds of taking my foot off the gas.

So my options are electrical issue, vacuum issue, or airflow issue.

Any known common vacuum issues with this car? Any other airflow sensors I should be cleaning? Electrical components I should check?

 

[lms]

Since you changed the motor, etc. I would look hard for something that is unplugged or not connected properly. Pull the plugs and take a look, are they while, black, etc. Is the battery fully charged?

 

[Gaege]

Since you changed the motor, etc. I would look hard for something that is unplugged or not connected properly. Pull the plugs and take a look, are they while, black, etc. Is the battery fully charged?

I just replaced the plugs, still have the old ones, numbered by cylinder. I'll post a pic in a bit. I'm not too good at reading spark plugs.

Would the battery have anything to do with it? Sometimes when starting the car it takes a bit to get the juice needed to kick the starter so I'm fairly confident the battery is on its last legs; I just thought that the ignition was carried out by the alternator, not the battery, during driving operation.

Correct me if I'm wrong.

 

[jakejm79]

A weak battery can place a draw on the rest of the electrical system even when the car is running.

 

[Gaege]

Just had my battery and alternator checked. Both are solid. Good news I guess. Still leaves a mystery though. Ugh

 

['97 Saab SE Turbo]

If the a/c compressor is running, it might kill the engine. Try running with the a/c off and see if it still stalls... Ron

 

[Gaege]

The A/C hasn't worked (at least the blower doesn't) since I got it. I've always got the air controls all turned off.

Fixing that whole system is on the to-do list.

I'm going to be pulling the throttle body for intense cleaning tomorrow evening in hopes that might be the problem.

 

[Gaege]

Here are the plugs I pulled along with their cylinder number. They look pretty typical to me. Anything stand out to you guys?

 

['97 Saab SE Turbo]

Looks like that disconnected vacuum line in one of your other posts will probably correct the idling problem, but new plugs every so often can't hurt either... Ron

 

[DistributedIntel]

Stalling. . .

I have an 02 T7 Convertible and there were a few causes for my stalling, I fixed all of them:

Broken vacuum lines
Crankshaft Position Sensor (This was the main culprit for idle stalling issues)
Improperly gapped plugs

Not sure if the T5 is known for CPS issues, but I would start there if you've tried everything else. It's cheap and fairly easy to replace at home. ;ol;