Skip the auto shop - Our mechanics make house calls

Q: Crank no spark after fixing seized engine due to bearing problem

asked by on

I need to know why I'm not getting spark.

My car has 155000 miles.
My car has an automatic transmission.

A: I'm assuming the engine was rebuilt, an...

I'm assuming the engine was rebuilt, and not replaced in this scenario. The first thing that came to mind was the crankshaft sensor. Did the new crankshaft come with a reluctor wheel? They usually need removed from the old crank to install on the new one. If you're not sure, remove the crank sensor and look into the hole. It is on the exhaust side of the engine block, closer to the transmission. Check to see if you have injector pulse if the reluctor wheel is present. You will need a noid light. If there is not a pulse, this would support a crank or cam sensor issue. Check for codes as well.

If you replaced the short block, or installed a used engine, and you are getting an injector pulse. Check for power with the key on at pin 3, white wire at the ignition coil connector. The power originates through the "main" relay and a 30 amp slow blow fuse labeled ECM. The ground pulse to the coils comes directly from the computer.

If you need help with this consider YourMechanic, as a certified technician can help you diagnose your starting issue and help you fix it accordingly.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Car will not start - 2005 Cadillac CTS

Okay, so hopefully you have another vehicle to get around in. The first thing you need to do is get that code scanned. Once you have the code, you should be able to narrow down the possible problems quite a...

Q: Problems with the electrical system in the car

The accessories not functioning properly is most likely due to when the battery was disconnected. The systems may have lost any programing of the accessories and gone back to factory settings. I would recommend having the accessories reprogrammed as needed....

Q: How do I unbuckle a seat belt?

To unbuckle a seat belt, simply press the Release button until the latch unbuckles, then remove the belt and allow it to retract fully.

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How to Renew Your Car Registration in Oklahoma(DELETED)
Having your car registered with the Oklahoma Tax Commission is an important part of driving legally in this state. You will need to do this within 30 days of moving to Oklahoma...