Occasional No Crank On Start

[chem_man]

After listening to your video a couple of times, I have a question. If you stand in front of the engine while someone else cranks the engine, does that horrible squeal emanate from the front of the engine compartment or does it emanate from the passenger compartment?

 

[OhioGuy]

After listening to your video a couple of times, I have a question. If you stand in front of the engine while someone else cranks the engine, does that horrible squeal emanate from the front of the engine compartment or does it emanate from the passenger compartment?

I'm not sure how you are hearing a squeal. There's no squeal. The only noises are me turning the key, the ignition chimes, and a normal crank/ignition of the engine after a few tries. The loud obnoxious noise was the radio turning on. It wasn't even that loud but it sounds super loud in the video.

 

[OhioGuy]

Disable the ignition or fuel pump by removing the appropriate relay or fuse, and then with the help of a second person, measure the battery voltage while the helper attempts to start the engine. Note the voltage reading while the engine cranks. Now, have the helper turn the headlights on and remeasure the battery voltage while the helper attempts to start the engine. Note the voltage reading while the engine cranks with the headlights on.

Now with the ignition or fuel pump relay or ignition restored, have your helper start the engine, turn the headlights on and have him turn the HVAC fan to the highest speed setting. Now put your Digital Multi-Meter on the AC volts function and choose either the lowest AC voltage range or the millivolt range. Place the negative test lead on the negative battery cable and then place the positive test lead on the battery output terminal on the alternator (the one under the rubber boot on the back of the alternator. Note that voltage reading (if the DMM is on the say 1 volt scale, you should see something like 0.0259 volts, or if the DMM has a mV scale you should see something like 25.9 mV).

Finally, please report the two cranking voltages and the voltage you see at the battery terminal on the alternator.

Does the ignition have to be disabled? I should still be able to get a voltage reading while it's cranking. Pulling the ignition relay/fuse would prevent it from cranking, therefore, turning the key to crank wouldn't put much load on the battery. Even with disabling the fuel pump, wouldn't the car still start briefly before stalling (until the fuel in the line runs out)?
I'll see what I can do, and report my voltage readings back here.

 

[chem_man]

OK on the loud noise being the radio. Best to turn it off when making a video.

Pulling the ignition relay or fuse will not affect the starter and the engine will still crank, but there will be no spark.

Pulling the fuel pump relay will keep the fuel pump from running and building pressure. The engine might try and run for a second or two, and if it does, let go of the key, let the engine stall and then try and start the engine again.

The idea is to see what the cranking voltage is and for cars with a properly working ignition and fuel system, engines tend to start right up making it hard to get a cranking voltage. So, pull the ignition relay or fuse, or the fuel pump relay or fuse so the engine will crank for more than a micro second in order to get a valid cranking voltage reading.

Pulling the starter relay will keep the engine from cranking because the starter solenoid will not engage because it is not getting any power.

Good Luck!