Troubleshooting Saab problems for pre-1994 engines: Can you do it?
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Troubleshooting Saab problems for vehicles made before 1994 is covered under Saab outboard diagnostic 1 system or Saab obd1. This covers all fuel injected engines made in early 1980 up to 1993 models. Knowing how to use this troubleshooting process should help you get to the bottom of what's going on inside your engine.
Computer-controlled engines and older engines have one thing in common: they both experience breakdowns that can be tested and repaired with simple troubleshooting steps. The engine computer can do special tests to diagnose vehicle problems prior to making DIY repairs or taking the car to a garage. However, on OBD1 Saab engines, there are necessary procedures before using the engine computer for troubleshooting.
For example, if your fuel filter is clogged up and not allowing enough fuel to be delivered to the engine, you can get trouble codes for oxygen sensor low voltage (too lean) because of it, even though the oxygen sensor itself is fine. This is why a hard code is not necessarily an indicator of a failed sensor which a lot of garages will replace as soon as they see the code.
Assuming you have a check engine light in your dash for a 92 S900 Saab indicating a hard failure, troubleshooting this can be done in 3 stages. These stages of troubleshooting Saab engines for OBD1 system are:
1.) Basic test
First part comprises mostly of visual inspection of engine wirings, wiring connections and vacuum connections including the routing of the wires and vacuum hoses. A damage wire or vacuum hose can cause the check engine light to come on even if the electronic components (like sensors) are OK.
Second part refers to mechanical inspection like compression test, back pressure test (max 2 psi allowed), fuel test (like regulator and fuel pump pressure) and ignition test (like testing the spark integrity). When doing these tests, try using remote starter to avoid using the ignition key which will activate the engine computer. If for any reason the computer programming is disturbed by using the ignition key, the computer can be reprogrammed by running the engine for at least 10 minutes.
2.) EGR test
Ported egr valve should be tested for operation by introducing vacuum to the ports and watching the engine if it changed rpm during idles. A simple test like checking the egr vacuum hose for cracks or leak can be easily performed. If the egr ports are clogged, the egr valve can be removed so the ported holes can be serviced.
3.) Test for fault codes
The engine fault codes can be retrieved in 2 ways: using a jumper wire in the diagnostic connector or using an organic scanner good for Saab obd1 codes. If possible, reset the code first and then take the code again after a road test to make sure you are chasing the right fault code. The diagnostic scanner connector is located under right front seat. Remember: clearing the code can be done either using a scanner or a jumper wiring switch.
Higher gas prices, increasing repair costs and required emissions testing are important reasons for today's Saab owners to test and tune their cars to keep them running smoothly. A detailed report about troubleshooting Saab engine can be found when you visit the author's website that gives assistance to Saab car owners.
Mr.Richard Trent is an automotive article writer specialyzing in car and truck repairs. Save $200-$300 on vehicle gas right now by watching his video at: http://www.automotivetroubleshootingsecrets.com
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