I changed the crankshaft position sensor in my 2002 Buick Regal LS V-6 3.8 L, but after the car warmed up the rpm's started jumping from 2500 rpm to 1000 rpm. I was driving down the road and the car continued to jump rpm's. Could this be a throttle position sensor issue or catalytic converter problem?

Bruce Bracey

• 1000 Answers
• Posted on May 08, 2009

SOURCE: 94 olds hard starts when warm, starts when cold and runs rich

If you can get a fuel pressure gauge, check and see if the pressure is 16 to 24 lbs after the engine has warmed up.
I would connect the pressure gauge when the engine is cold, make sure it does not leak or touch anything hot, place the gauge between the hood and the windshield and drive the vehicle until it is at the temperature you feel it "starts hard". Shut the engine off and try to repeat the no start or hard start and make sure the pressure is correct.
Also, when you shut the engine off, watch the pressure and make sure it holds and does not drop to (0 LBS) of pressure.
One last question, has the fuel filter been changed in the past 30K.
Let me know.
Regards,

SOURCE: Crankshaft Position Sensor and Camshaft Position Sensor

REMOVE OR DISCONNECT

1. Serpentine belt from the crankshaft pulley.
2. Raise the vehicle on a hoist.
3. Right front tire and wheel assembly.
4. Right inner fender access cover.
5. Using a 28 mm socket, remove the crankshaft harmonic balancer retaining bolt.
6. Crankshaft harmonic balancer using tool J 38192 or equivalent.
7. Sensor electrical connector.
8. Foreign object deflector.
9. Sensor and pedestal from block face.
10. Sensor from pedestal.

1. Loosely install the crankshaft sensor on the pedestal.
2. Position the sensor with pedestal attached on special Tool J 37089.
3. Position the special tool on the crankshaft.
4. Bolts to hold the pedestal to the block face, torque to 20-40 Nm (14-28 lb.ft).
5. Torque the pedestal pinch bolt to 3-4 Nm (38-40 lb.in).
6. Remove special tool J 37089.
7. Place the special tool 37089 on the harmonic balancer and turn. If any vane of the harmonic balancer touches the tool, replace the balancer assembly.
8. Balancer on the crankshaft.

• Apply thread sealer (GM 1052080) or equivalent to the threads of the balancer bolt.

1. Torque the crankshaft bolt to 140 Nm + 56°(104 lb.ft + 56°).
2. Foreign object deflector.
3. Electrical connector.
4. Inner fender shield.
5. Tire and wheel assembly, torque to 140 Nm (104 lb.ft).
6. Lower the vehicle.
7. Serpentine belt.

SOURCE: i have a 1999 buick regal ls dying.

I found the problem. It was the crank position sensor. There was also a cracked vacuum hose connecting to the diaphragm on the fuel rail. Replaced both and my 92 Buick no longer dies. For the guy who's Buick was dying when using the turn signals - replace the crank position sensor. One of my symptoms of my Buick dying was when I used my turn signals. Use of turn signals places a varying load on the electrical system which messes up the crank posistion sensor if it is going bad.
Bob

SOURCE: Engine surge during warm up.

Try changing your PCV valve make sure the hose is clean and not full of oil. Also check the elbow end that goes to the intake they tend to collapse from oil saturation. Hope this helps.

SOURCE: 1998 Regal LS sputters/stalls; alternator keeps failing

i'd say you have a ground problem if you are burning up alternators... sorry if that don't help... i would have to see car to better appreciate problem.