Engine ignition seems to shut off and the car hesitates and bucks?

Tiny
2CP-ARCHIVES
  • MEMBER
  • 2002 BUICK PARK AVENUE
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 44,000 MILES
I have an intermittent problem that does not seem associated to temperature, environment, and is most visible at highway speeds but also happens at idle occasionally. The engine ignition seems to die and the car hesitates and bucks. This can be seen in the tachometer, which briefly starts falling to zero. Also, when the problem occurs, the ammeter drops down and slowly returns. After the problem occurs, the MIL will illuminate the next time the car is started but can be turned off by killing the engine and restarting it. With an Actron scan tool, I found 2 codes in the system. They are 321 and 361. The scanner said that 321 is "18x interrupts/ignition" and 361 is "EST not toggling". Studying the wiring diagram shows that an EST signal goes into the ignition module and that the EST signal uses the crankshaft sensor and camshaft sensor as reference signals. I replaced the crankshaft sensor and then the ignition module but the problem is still there. Any help would be appreciated
Tuesday, October 19th, 2010 AT 9:26 PM

1 Reply

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good morning.

The crank position sensor is what sends signal to the ICM for firing the injectors and spark. The tachometer is run off that as well.

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

I attached the procedure for you of the crank sensor replacement. After you replace it, you will need a scan tool to perform the relearn procedure. I attached that below for you.

I also attached the wiring diagram of the system for you as well.

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Roy

Was this
answer
helpful?
Yes
No
Sunday, September 19th, 2021 AT 8:26 AM

Please login or register to post a reply.

Related Engine Stall While Driving Content

Sponsored links