I've recently started having a probelm with my '99 L stalling at low RPM. First incident was during a low speed right hand turn and the motor stalled leaving me without any power steering. Fortunately it didn't result in an accident. I'm noticing the idle dropping below 500 RPM as well during deceleration and nearly stalling. I'm running an old superchip on the street setting that's been in there for several years. Also have a 80mm Pro-M that been in there for a couple years. No recent changes to anything else. I've inspected the motor and don't see any loose electical or vacuum lines. Motor still running strong and no roughness at all. Anyone seen this before? Maybe the fuel filter?

 

IAC valve maybe.

 

This sounds like it could be the fuel pumps, I have heard of or 99's having this problem. Do a search.

I think there is some sort of tube or hose or fitting coming loose. You have to drop the tank which is never fun.

I would also change the fuel filter, just to say you have eliminated that problem.

IAC is another thing to check.

Fuel pumps are my best guess.

Hope this helps

 

Change the easy stuff first!!

 

A little dirt in the EPC solenoid to the Toque Converter Clutch can cause the converter to not disengage, and that would do it, not the first thing I'd look for, but something I have seen before.

G