Motor cranks but I have no injector Pulse?

Tiny
BRIAN THOENNES
  • MEMBER
  • 1995 PONTIAC SUNFIRE
I have a 95 sunfire the motor cranks but I have no injector pulse I have no spark and no fuel pressure. When I hook up the scanner I have power to it
Sunday, January 2nd, 2011 AT 7:50 PM

1 Reply

Tiny
SQM
  • MECHANIC
  • 6,383 POSTS
Hello,

First check to see if you have power to the injector harness. If you are getting 12V to the harness then it could be a sensor issue.
The crank position sensor sends signal to the ECM and the ECM uses that data to send injector pulses to start and run the engine.

It could be because of a faulty crank position sensor that you are having crank and no start. Overtime heat and vibration will make the crank sensor loose its calibration and give faulty signal. It could also have bad wiring.
Check to see if you have getting 5V to the crank sensor harness.

You might find these articles helpful:

https://www.2carpros.com/articles/how-a-crank-shaft-angle-sensor-works
https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor
https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

I have attached diagrams for your reference.

Please let me know of any questions.

Thank you.
Was this
answer
helpful?
Yes
No
Wednesday, August 18th, 2021 AT 8:10 AM

Please login or register to post a reply.

Sponsored links