In need of help with my 944 porsche
Discussion
Try the Ignition troubleshooting on http://www.clarks-garage.com/
Testing For Lack of Spark
The first step in testing for lack of spark is to verify that a no spark condition actually exists. A simple spark tester available at most auto parts stores is very handy here. I recommend removing the fuel pump fuse to keep the fuel pump from running during spark testing.
Disconnect one of the plug wires and connect the spark tester in series with the spark plug. Crank the engine and look for spark. You'll see the spark pulsing inside the tester as the engine turns over.
If there is no spark at the spark plug, disconnect the main lead from the ignition coil to the distributor cap and connect a spark tester in series with the coil wire. Crank the vehicle and check the tester for spark to the distributor.
If you get good spark at the main lead to the distributor and no spark at the spark plug, the distributor cap and/or rotor is bad and should be replaced. If there is no spark at the distributor main lead, proceed with ignition troubleshooting using IGN-04, Ignition System Troubleshooting.
Or
since you changed the fuel pump.
Disconnect one fuel injector connector and attempt to start car. If the car starts and runs, where it would not before, then the Fuel Pressure Regulator (FPR) is most likely bad and should be replaced. Bascially when the FPR fails causing the fuel rail pressure to go high, the injectors have too high a differential pressure across them, they draw too much current, and the injector driver shuts down. Disconnecting one injector wire reduces the injector current enough to allow the engine to start. Realize that the car will run very rough as it's running on three cylinders
The first step in testing for lack of spark is to verify that a no spark condition actually exists. A simple spark tester available at most auto parts stores is very handy here. I recommend removing the fuel pump fuse to keep the fuel pump from running during spark testing.
Disconnect one of the plug wires and connect the spark tester in series with the spark plug. Crank the engine and look for spark. You'll see the spark pulsing inside the tester as the engine turns over.
If there is no spark at the spark plug, disconnect the main lead from the ignition coil to the distributor cap and connect a spark tester in series with the coil wire. Crank the vehicle and check the tester for spark to the distributor.
If you get good spark at the main lead to the distributor and no spark at the spark plug, the distributor cap and/or rotor is bad and should be replaced. If there is no spark at the distributor main lead, proceed with ignition troubleshooting using IGN-04, Ignition System Troubleshooting.
Or
since you changed the fuel pump.
Disconnect one fuel injector connector and attempt to start car. If the car starts and runs, where it would not before, then the Fuel Pressure Regulator (FPR) is most likely bad and should be replaced. Bascially when the FPR fails causing the fuel rail pressure to go high, the injectors have too high a differential pressure across them, they draw too much current, and the injector driver shuts down. Disconnecting one injector wire reduces the injector current enough to allow the engine to start. Realize that the car will run very rough as it's running on three cylinders
Ok so I disconnected two of the injectors the car started and ran rough I let it run for about a min like this then cut it off plug the other two back up and started the car now here's the thing it ran terrible it back fired once and kinda sounded like it was missing if I tryed to give it gas it it just acted like it wanted to die but if I released it went back to idleing where it should just with back firing and it sounding like it missing so any new thoughts?
replace the DME relay
Also, if it can idle but not rev, it may be a blocked air intake. Have you checked the air intake? Maybe remove the air filter and start it ( I dont recommend driving without an air intake, but starting it will be fine.
Make sure the connector is in place onto the barn door air flow sensor, itself is free from obstruction
Whats comming out of the exhaust at the back?
Also, if it can idle but not rev, it may be a blocked air intake. Have you checked the air intake? Maybe remove the air filter and start it ( I dont recommend driving without an air intake, but starting it will be fine.
Make sure the connector is in place onto the barn door air flow sensor, itself is free from obstruction
Whats comming out of the exhaust at the back?
williamp said:
replace the DME relay
Also, if it can idle but not rev, it may be a blocked air intake. Have you checked the air intake? Maybe remove the air filter and start it ( I dont recommend driving without an air intake, but starting it will be fine.
Make sure the connector is in place onto the barn door air flow sensor, itself is free from obstruction
Whats comming out of the exhaust at the back?
well it kinda looks like its burning fuel it dark out so its hard to tell the color of the exhaust coming out but it seems like fuel I'm unsure of this smacking sound that's coming from the front of the engine the closest thing I can relate it to is that it sounds like its missing...some ppl are telling me its out of time ok but that doesn't make sense bc it wasn't out of time right before it broke down so why would it be out of time now? And ok I'll go buy a dme relay I personally don't think that's the problem but I'm out of ideas so I'll do that in the morning Also, if it can idle but not rev, it may be a blocked air intake. Have you checked the air intake? Maybe remove the air filter and start it ( I dont recommend driving without an air intake, but starting it will be fine.
Make sure the connector is in place onto the barn door air flow sensor, itself is free from obstruction
Whats comming out of the exhaust at the back?
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