Car won’t start
Every day I see questions posted on auto forums with the question; “Why won’t my car start?” Of course the poster doesn’t list the year, make, model, or engine in their vehicle. They just want to know why it won’t start. But without knowing that basic vehicle information, it’s almost impossible to answer the question. Every vehicle is different. And the reason why one vehicle won’t start may be completely different than the reason for another vehicle.
Plus, “won’t start” isn’t at all helpful. Do you mean the starter won’t crank the engine when you turn the key? Or do you mean the engine cranks, but won’t fire up? Or perhaps it fires up and dies right away—because that could also mean that the “car won’t start.” The point here is that you must be specific if you want help. Here are the terms and what they mean.
Won’t crank with no sound
You turn the key and hear nothing—no click. This can be caused by dirty battery cables, a bad ignition switch, a bad starter relay, a bad starter solenoid, or a bad starter motor.
Won’t crank but clicks once or clicks rapidly
At least this tells us the ignition switch is sending power to the relay and starter motor. If you hear a single click, turn on the dome light and try again. If the dome light dims to almost nothing, that can be a sign of a dead battery or a shorted starter motor. If you’re stuck away from home, continue to turn the key for about 6 or 7 more times. Then let it sit for about 5 minutes. If the problem is the battery, the continued key turning may heat it up enough to get you enough power to turn the starter motor. BUT, if you detect a burning smell, stop immediately. That means you’re cooking the starter motor. (Not that you care that much, you’re going to have to replace it anyway, but it could ignite the insulation on the motor windings). Click here to see how to check the battery.
A rapid clicking, sounding almost like a machine gun, is a sign of a weak battery. The battery is providing just enough power to pull the starter drive towards the teeth in the flywheel, but not enough power to hold it in place and turn the starter.
For other tips on “won’t crank” click here
Starter makes a high pitch spinning sound—like WHIRRRR
That’s the sign of a failed starter motor drive gear. Try to start the engine 5 or 6 more times to heat up the grease inside the starter motor drive. That may buy you one more start. But that trick won’t carry you very far, so drive it right to the shop and have them replace the starter motor.
Cranks but won’t fire up
If the engine cranks as fast as it normally does but won’t fire up, that can be a sign of a bad crankshaft position sensor, bad fuel pump, or a problem with your anti-theft system.
If you own a Ford vehicle, turn the key to the RUN position and wait for the Check Engine light to come on. Then crank the engine. The light should go out while cranking. If it does, that means the computer is getting a good signal from the crankshaft position sensor. If the light stays lit, start your diagnosis with that sensor.
Next, check the inertia fuel cutoff switch. This is fairly exclusive to Ford products. It’s designed to turn off power to the fuel pump if the vehicle is ever involved in a crash. But the sensor can also activate if someone bumps your car in a parking lot. It’s in a different place for each Ford model. So get out your owner’s manual. Find the location and press the reset button.
If you own a different vehicle, look at the light for the SECURITY system. If it’s flashing or stays on, that can be an indication that there’s a system fault. Click http://www.ricksfreeautorepairadvice.com/category/repair-topics/alarms -and-antitheft-systemsto read about anti-theft systems
Click http://www.ricksfreeautorepairadvice.com/make-model/saab-make-model/no -crank-no-click-no-start-chevrolet-buick-pontiac-saturn-hummer-cadilla c-wiring-diagram-starting-system-wiring-diagram to read about GM anti-theft systems
Next, try starting the vehicle by holding the gas pedal down part-way. If that helps at all, chances are you have a failing engine coolant temperature sensor. Those sensors can fail partially—not enough to set a check engine light, but enough to throw off the computer. The failed sensor makes the computer think the engine is warmer than it really is. So it provides a very lean mixture to a cold engine. By pressing the gas pedal, you override the computer’s commands and force it to provide more gas. If that works, test or replace the sensor.
If the engine isn’t getting fuel, you’ll have to perform a fuel pressure and fuel volume test and that requires special tools. Not a job for a DIYer.
Starts and dies.
This can be can be caused by a dirty or failed idle air control valve or a vacuum leak. The idle air control valve regulates how much air comes into the engine when you’re at idle. If it’s not working properly or the passages are dirty, the engine will either have too much air or will be starved for air. A vacuum leak can also cause an engine to die after starting because the leak dilutes the rich mixture the computer is providing.
Got a car question? Click here and send it to me. I’ll do my best to get you an answer.
For more information on this repair or any others for your vehicle, buy an online subscription to either Alldatadiy.com or eautorepair.net. Click on this link to compare the two services: Compare Alldata and Eautorepair.
If you just need information for a single repair and want to save money,eautorepair offers a lower price 1-week subscription for only $11.99. Or, if you’ll be working on this vehicle in the future, you can buy a 1-year subscription (Alldatadiy.com for $26.99, or eautorepair.net $29.99)
© 2012 Rick Muscoplat
Alldatadiy.com
eautorepair.net
Alldata and Eautorepair are both professional grade shop manuals. You’ll find more in-depth information and more complete wiring diagrams, along with descriptions of how the systems work. And, you’ll get all that at a price you can afford. Check them out!
Click HERE to read AUTO REPAIR ARTICLES sorted by topic
Click HERE to read some cool DIAGNOSTIC TIPS
Click HERE to read ACURA articles
Click HERE to read AUDI articles
Click HERE to read BMW articles
Click HERE to read CHRYSLER articles
Click HERE to read DODGE articles
Click HERE to read FORD LINCOLN MERCURY articles
Click HERE to read GM articles
Click HERE to read HONDA articles
Click HERE to read HYUNDAI articles
Click HERE to read INFINITI articles
Click HERE to read JEEP articles
Click HERE to read KIA articles
Click HERE to read MITSUBISHI articles
Click HERE to read NISSAN articles
Click HERE to read SUBURU articles
Click HERE to read TOYOTA articles
Click HERE to read VOLKSWAGEN articles
The post Car won’t start appeared first on Rick's Free Auto Repair Advice.