Engine Performance problem
1997 Saab 9000 4 cyl Front Wheel Drive Manual 130000 miles
Ive got a 98 Saab 9000 aero 5 speed, with 130k on it that will not run. The symptom is that it will start, rpms go to 1000 rpms, then promptly dies. If I pull the MAP sensor plug, the car will idle at 1,000 rpms all day long, but will rev to about 3,000 and then die. I replaced the following:
Di cassette, MAP sensor, plugs, fuel pump, fuel press regulator, ECU, fuel filter, apc was inspected, crank position sensor, tested the wiring from the ecu to the fusebox, to the DI, to the crank pos sensor, apc, and fuel pump, most of the hoses to include those to and from the turbo, both oxygen sensors.
I am showing no fault codes except when I pull the MAP plug. If I pull the MAP plug, start the car, and hook the MAP back up with it running, it will idle fine for about 10 min, then die. I have talked to several “experts", including some that specialize in SAAB’s and they are all perplexed without me brining them the car. The problem is I am 250 miles away from the nearest shop that can work on it. I cant drive it around the block, but it idles just fine with that plug pulled. I am desperate for some advice I am fairly mechanically inclined, but this has me completely lost. Thanks!
This is what I have on the subject
Hope it help
Check temperature sensor
Check Manifold Absolute Pressure (MAP) sensor vacuum
Check for proper CO setting (if adjustable) on mass airflow sensor.
Inspect for broken mass airflow sensor filament (if equipped).
Check mass airflow sensor continuity.
Inspect induction system.
Inspect for vacuum leaks downstream of throttle valve.
Inspect duct between mass airflow sensor and throttle body (if equipped).
Check idle speed.
Check injector operation and opening duration.
Inspect injectors for leaks.
Check fuel pressure and pressure regulator.
April, 28, 2010 AT 12:12 PM
Thanks for the reply. The MAP sensor is mounted on the firewall and has good vac. It is a brand new unit. The fuel press regulator has also been replaced, as well as the fuel injectors and the fuel pump. I am not sure what the temp sensor has to do with it. Is this the temp sensor below the intake manifold? I checked continutiy between the MAP and the ECU as well as the ground to the MAP, and it is good. There is a temp sensor just before the throttle body, but I do not think it is a factor. The car does run better with the intake removed. It seems to have troubles with any positive air pressure from the turbo. Idle speed is where it should be as long as the MAP leads are disconnected. There is no CO adjustment that I know of on the SAAB 9000 that I know of, and I have power to the ignition casette during start up and after the engine dies. Fuel pressure is within tolerance.
April, 28, 2010 AT 12:53 PM
Disconnect and check Mass Air Flow Sensor
i would suspect that
remove it and check inside for dirt
April, 28, 2010 AT 2:50 PM
Thanks again for the quick reply. The Saab 9000 2.3L Aero Turbo with a 5 Speed does not have a mass air flow sensor that I can find. I looked up the part, and there is none for that year and model