Tip & How-To about Toyota Celica

Test tools for autos

In order to eliminate the various items in any failed system, you must be able to properly test the components. In order to test the components, you must have testing equipment. Would you rather replace a $400 ECU only to find out later that it was a $12 distributor cap? NOOO. That's why you are here on fixya. You want help. Well, we want info from you. How do you obtain such info? That's right, say it with me. . .Test Equipment. So, the next obvious question is, what do I need?

1) Timing Light. - About $40 from parts stores.
2) Digital Voltmeter - reads Volts DC and Ohms at a minimum.
3) Pressure gage with various fittings.
4) Compression test kit.
5) Feeler gages in Metric and Standard.

If you have this equipment, you can test a lot of systems, eliminating good parts, to narrow it down. Your goal is to zero in on that one part that is bad.

It is often VERY helpful if you have a manual. Most are less than $30.

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how to check if your ECM is working. Mine maybe bad. I need to make sure before I spend the money....91 Geo Tracker

Only a professional can do testing up to the
PCM ,to eliminate all other items & wiring issues
You could if you have wiring diagrams for your vehicle
& know how to use a volt meter & not ground out the pcm
while doing your testing
They don't fail often,so I would be testing the entire
engine compartment & all systems

Aug 10, 2013 | 1995 Geo Prizm

2 Answers

new battery keeps going dead.i exchanged later it went dead had alternator checked and it is ok

WEll, something is causing the issue.... First, fully charge the battery, then disconnect the negative and put a volt meter or test light in series (between the terminal and the cable). Disable interior lights, and test for draw of current.
Essentially, if the light lights, too much current is being drawn out of the battery. So, you disconnect fuses, and other items until the light goes out. This should help you find the offending component.

IF no light lighting, perhaps the battery itself has issues. Leave it disconnected overnight, and see if it is discharged...If yes, the battery would be suspect.

There are diodes in the alternator that fail and can cause voltage to be drained. Some tests to the alternator fail to reveal the fault. the best test is an Scope, but you can isolate diodes and test with continuity tester.

Feb 04, 2011 | 1999 Ford Escort

1 Answer

2003 ford expedition 4.6 v-8 will turn over but wont start

This is a wide open question, but the first thing to ask is if the vehicle had been in an accident or jolt of some kind, the fuel cutoff switch may need to be reset. That should be located in the rear of your vehicle on the drivers side in a panel just inside the rear hatch door. If that is not the issue, you will need to start eliminating items, like the fuel pump. That can be tested using a fuel pressure guage and connecting it to the schroeder valve on the fuel rail. If you are getting proper fuel, your next test can be checking the coil pack. I believe yours would be with each spark plug. There are many other items and details for each item to test, but you need to start eliminating the easiest possible problems first.

Oct 21, 2010 | 2003 Ford Expedition

1 Answer

Car wont start

The amount of power required to start your engine is significantly greater than what it takes to play the radio or burn the headlights, so those items working don't necessarily mean the battery is adequate. Your description indicates the following:
  1. Battery: an old or damaged battery can fail without notice.
  2. Belt: the squealing belt indicates that it is loose or glazed and does not have the tension in order to turn components at their proper speeds. This could lead to the alternator not performing as it should.
  3. Alternator: loose connections, a failing component, or a loose belt can cause the alternator to perform poorly.
The above items can be checked by a qualified mechanic in a matter of minutes or less. Some part stores offer a free test of your charging system, whether the component is on the vehicle or you have removed the part and carried it in for testing.

Apr 11, 2010 | 2000 Kia Sephia

1 Answer

Will turn over but will not start

There are a great number of items that can fail and give you that problem. Likely the two most common are the crankshaft sensor and fuel pump.
What you need to do though is to determine if you have spark (hold an ignition wire near the block after sticking a screw or other metal object into the plug connector and have someone crank it over...you should have a decent blue spark that will jump at least 1/4" gap) If you don't , you will need to check the ignition system components. To check pump, turn the key to "on" while someone listens at the tank) If silent, check the pump relay in the poser distribution center and the pump itself for power.
To do any testing, you will need a decent manual like haynes or chiltons (about $20 in most larger parts stores) and a good digital multi-meter.
Testing components is very important because parts are expensive and many are not easy to replace. Testing eliminates changing unnecessary parts. No decent shop will replace parts without testing...neither should you!!!
Good Luck

Nov 15, 2009 | 1994 Jeep Grand Cherokee

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