1999 STS dies at intersections

[noobie]

Hi, I have a 1999 Cadillac STS that has an ongoing problem when I come to a traffic stop. Sometimes the engine cuts off, before it does, it starts to jerk a bit, some other times it jerks but doesn't die. It doesn't throw any engine code so I have no clue. I'm thinking of fuel filter. What do you guys suggest?

Thanks.

[JC316]

If it were the fuel filter, I would think that it would die on the highway from lack of fuel.

[CadillacSTS2003]

its a 99 but still possible and usually they throw codes
but maybe crank position sensors

[RunningOnEMT]

does it herk and jerk on throttle up ... and stutter when you just blip the throttle

might be a high resistance connection in the ignition

melted connector, bad wire, bad plug...

if it was a fuel filter bad enough to shut the car off he'd get a lean bank code first

[noobie]

Once I remove the brake and the car starts rolling, it won't die. It only dies when it's fully stop. The car revs up just fine, no jerk or herk when throttle is applied. No stutter when throttle is removed.

I guess it's not fuel filter then. Some mechanics said it was a fuel filter.

[submariner409]

Search for CKP or Crankshaft Position Sensor. The low-rpm stall or shudder is common in a CKP fault. There was a TSB on them, and quite a few were replaced under warranties, from '99 through '02. Have your GM dealer pull the service history for your VIN. A CKP service, by GM, will be there. There are 2, A and B. Replace them both. The bad ones are stamped "Mexico", while the service replacements are stamped "Japan". AJxtcman had the date codes in here about 6 months ago. The threads will give you the online GM dealers to order from.

[CadillacSTS2003]

2003 also had that problem
mine were replaced with only 1200 miles...

[Ranger]

It's not the fuel filter. Fuel filter would cause a problem at high fuel flow (WOT or highway). Sounds like your TCC is not disengaging. It's like trying to stop a car with a standard trans without stepping on the clutch. Pull the DTC's.

[RunningOnEMT]

Originally Posted by noobie

Once I remove the brake and the car starts rolling, it won't die. It only dies when it's fully stop. The car revs up just fine, no jerk or herk when throttle is applied. No stutter when throttle is removed.

I guess it's not fuel filter then. Some mechanics said it was a fuel filter.

see if your TCC lockup clutch is disengaging... there should be a lead into the trans put a multimeter on it and see if it clicks on and off ...

[noobie]

It died 2 times on me this morning when driving to a gas station. I have to use both of my feet to keep it from dying, one foot on the brake pedal, and one foot on the gas pedal. If I apply a tiny pressure on the gas pedal, the car won't die, but if I release the gas, it would start to jerk.

Do you guys still think it's TCC or Crankshaft position sensor?

[99 Seville Caddy]

What about the throttle position sensor or the idle speed motor?

[noobie]

Originally Posted by 99 Seville Caddy

What about the throttle position sensor or the idle speed motor?

Yeah, I'm looking at these 2 right now. Looks like my throttle body is also full of carbons.

[Ranger]

Clean the TB. The ISC air passage may be carboned closed.

[saltr]

My 02 Eldo had very similar symptoms to yours. It finally quit one day long enough to trip a code. I believe it was P0385,ended up replacing both crank position sensors,just as submariner409 mentions in his post.-saltr

[BigBoy_4005]

What about a stuck EGR valve? I learned (while goofing around with output overrides using a scan tool ) that it sounds odd, actually like a lopey stock car, when the EGR is open at idle.....Until it dies that is.