How do you know for sure? A 95 sunfire and cavalier manual says it does. Is it harder to diagnose with an OBD 1?
March, 23, 2011 AT 9:23 PM
That is a transition year and they mixed components in the system. Many of them had an OBD1 system but and OBD2 connector. They can only be read with an expensive professional scan tool.
March, 25, 2011 AT 1:49 AM
Darn! Thank you. It figures the diagnostic tool I can use for free isnt compatible. My car wont fire, no spark when ground to engine and turned over. Ive heard an outrageous number of thimgs it could be, do you suggest I start by testing w continuity tester under the hood( relays n such) after that if no luck, what do I do next to check ignition issues? Thank u
March, 25, 2011 AT 2:08 AM
All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.
Every engine requires spark, fuel and compression to run. That's what we have to look for.
These are the basics that need to be tested and will give us the info required to isolate a cause.
1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.
2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.
3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.
4) If all of these things check good, then you would need to do a complete compression test.
Once you have determined which of these functions has dropped out,
you will know which system is having the problem.
March, 25, 2011 AT 3:37 AM
Not to sound stupid(just extremely inexperienced)is a noid light just have the point on end and bulb on the other and whats the difference between it and the continuity tester? Gosh I wish u could just come look at it lol!
March, 25, 2011 AT 12:39 PM
The noid light is a special, high impedance bulb designed not to damage the computer by drawing too much current. They make a few different styles for different makes of cars too. You just plug it into any of the injector plugs and crank the engine. If the bulb flashes, then you have both signals requires for the injectors to work.