Skip the auto shop - Our mechanics make house calls

Q: Will not start.

asked by on

I changed the engine from 97 to 99. Do I have to put the crank sensor and cam sensor from the 97 onto the 99?

My car has 140000 miles.
My car has an automatic transmission.

The sensor will be the same. What you need to make sure of is that the new motor has the tone ring installed on the balancer. The same goes for the camshaft sensor. A missing tone ring is a very common issue with motor swaps. The year of the motor rarely makes a difference. They are still the same motor.

Once you have confirmed there are tone rings for both the camshaft and crank sensors, the next thing to do is to figure out what is missing. Every ICE (internal combustion motor) needs fuel pressure, injector pulse, spark and camshaft timing to run. Figure out what is missing and diagnose the truck accordingly. Something else that is often overlooked, if the replacement motor is a used motor, they will often need some oil squirted into the cylinders to give them enough compression to start. This is normal and does not mean there is a problem with the motor. Don’t squirt so much oil in that the cylinders will hydrolock. A few squirts from an oil can is all that is needed.

Another often missed item, if the replacement motor is used, the injectors can become stuck. Simply use a small hammer to tap on them while attempting to start the motor. This needs to be done with care. Use a stethoscope or small hose to confirm the injectors are working. You are listening for a clicking noise. If you don’t here it, either they are not getting injector pulse or they are sticking from sitting for to long.

I recommend the following inspection to help you figure this out. Car is not starting

Good luck!

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
  1. Home
  2. Questions
  3. Will not start.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Oil light ON repair

Hello there, thank you for asking about your 1985 BMW 635CSi. I'm guessing you're talking about the Oil Level Light and not the Pressure Light. If this happened right after the accident, I'd be willing to bet the sensor and/or...

Q: The clutch went out and clutch fluid leaking out.

Check the slave cylinder under the vehicle and see if the seal blew out. Fill up the clutch master cylinder if its low and pump the clutch pedal a couple of times and then look for the leak. Pull back...

Q: What does the check brake system warning mean in the message system?

Your car is equipped with a number of different sensors designed to monitor critical systems for malfunctions and problems, including your brakes. If you see a warning message that reads “Check brake system” come on in your message center, it...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.