Engine almost stalling
Thread Starter
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Joined: Oct 2002
Posts: 50
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From: Charlotte NC
Engine almost stalling
On an L98 with bolt on mods, about once a day (or per drive), the engine misses badly, RPM's drop to 200 or 300, for just one beat. Then catches back again, back to normal idle. I only get this at idle, like at a stoplight, when the car is warm.
Also, the check engine light is on. Has been for several months. Mechanic said it wa a "soft code", I guess meaning more warning than dire need. He said not to worry about it. No problems otherwise, except when the car almost stalls (described above), the light goes back off. The light comes on initially after about 10-15 minutes of driving, and once on, rarely goes off again untill car is turned off.
Any advice? I'm lacking in tools and know-how, but am willing to experiment or at least learn. Is there a cheap way for me to diagnose the code?
Thanks all...
Also, the check engine light is on. Has been for several months. Mechanic said it wa a "soft code", I guess meaning more warning than dire need. He said not to worry about it. No problems otherwise, except when the car almost stalls (described above), the light goes back off. The light comes on initially after about 10-15 minutes of driving, and once on, rarely goes off again untill car is turned off.
Any advice? I'm lacking in tools and know-how, but am willing to experiment or at least learn. Is there a cheap way for me to diagnose the code?
Thanks all...
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Engine almost stalling (triple_black_89)
First off I don't know what is a "soft code"; so I suggest you pull any codes and come back with them:
-locate the ALDL under the left dash just to the right of the steering wheel
-remove the plastic cover, in installed
-insert the ends of a paper clip into pins A & B (upper right pair)
-turn the ignition on, but do not start the engine
-you will first see three "12s" flashed
-then each trouble code will be flashed three times
-finally three "12s" will flash, indicating the last code
-jot down all the non-12 codes and post them here
-turn the key off, remove the pape clip and install the cover (if present)
-locate the ALDL under the left dash just to the right of the steering wheel
-remove the plastic cover, in installed
-insert the ends of a paper clip into pins A & B (upper right pair)
-turn the ignition on, but do not start the engine
-you will first see three "12s" flashed
-then each trouble code will be flashed three times
-finally three "12s" will flash, indicating the last code
-jot down all the non-12 codes and post them here
-turn the key off, remove the pape clip and install the cover (if present)
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: Engine almost stalling (65Z01)
I guess he's referring to an "intermittent" code; one that isn't there when you run the ALDL check.
The manual says they are usually caused by a loose connection, arching plug wire or one of several shorts to ground.
Jake
The manual says they are usually caused by a loose connection, arching plug wire or one of several shorts to ground.
Jake
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: Engine almost stalling (bogus)
a stab: try cleaning your IAC. :thumbs:
Clean the IAC and the opening in the throttle body where it screws in. A lazy IAC will cause the rpms to drop too low before it opens up enough to catch the idle speed and raise it.
Clean the backside of the throttle body butterflies
If you have a ScanTool, etc., check the IAC counts. They should be in the area of 20-30 at idle. This setting will give the IAC more range of control over idle speed.
Then all the other basic stuff like spark plug/wire condition; TPS voltage, ignition timing, leaking vacuum hose (some crack from the heat and begin to leak vacuum), MAF sensor (check that neither of the two wires is broken).
Hope this helps.
Jake
Thread Starter
Advanced
Joined: Oct 2002
Posts: 50
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From: Charlotte NC
Re: Engine almost stalling (JAKE)
Thanks for the help guys... i"m going to try and clean the IAC/throttle body and see waht happens. I konw that the codes are not "saved", so I'll have to try and scan it while the light is on. Will the paper clip trick with the engine running?
Pro
Joined: Sep 2003
Posts: 670
Likes: 1
From: charlotte nc
Re: Engine almost stalling (triple_black_89)
The engine needs to be stopped with the ignition ON in order to get the ECU to put out the codes. If you crank the engine with the A/B pin jumpered, you will put the ECU in open loop and the idle will be 1000 RPM. No harm done but it wont get the codes that way. :cheers:
