SL/R129: 16 Pole Diagnostic Connector (X11/4) 1993 300 SL
12-13-2017, 04:16 PM
#26
Junior Member
Thread Starter
Hi Bob,
You're right. I forgot to deflect the airflow sensor plate! When it's deflected, fuel sprays from the injector. However, the engine still will run only when I prime it through the airflow sensor. It stops running as soon as it uses up the prime. The only error code on sockets 3, 8 and 14 is code 17 on socket 8. As previously discussed, the crankshaft position sensor is new. Could the problem be with the crankshaft position triggering unit on the flywheel itself? Is there a way to check that? Any ideas?
Thanks,
Harry
You're right. I forgot to deflect the airflow sensor plate! When it's deflected, fuel sprays from the injector. However, the engine still will run only when I prime it through the airflow sensor. It stops running as soon as it uses up the prime. The only error code on sockets 3, 8 and 14 is code 17 on socket 8. As previously discussed, the crankshaft position sensor is new. Could the problem be with the crankshaft position triggering unit on the flywheel itself? Is there a way to check that? Any ideas?
Thanks,
Harry
12-14-2017, 09:06 PM
#27
Banned
I don't know that you can satisfactorily test the crank position signal or any associated components without an oscilloscope. If there were a problem in this area with your engine I assume it would not be able to start.
12-15-2017, 03:32 PM
#28
Junior Member
Thread Starter
Hi Bob,
I didn't realize one could safely run the engine with the MAS out, but with the fuel pump jumper connected. With the jumper in place, the engine starts and continues to run. Does this signify that the rebuilt MAS is defective?
Thanks,
Harry
I didn't realize one could safely run the engine with the MAS out, but with the fuel pump jumper connected. With the jumper in place, the engine starts and continues to run. Does this signify that the rebuilt MAS is defective?
Thanks,
Harry
12-16-2017, 12:47 PM
#29
Banned
Possibly. You need to evaluate the engine RPM signal the MAS receives from the EZL ignition module. With the engine idling you measure the DC voltage between sockets #16 and #4 of the MAS connector. I suppose you should see a voltage of around 6-7 volts. No voltage at all indicates wiring or a faulty EZL; voltage would suggest a faulty MAS.
12-16-2017, 05:18 PM
#30
Junior Member
Thread Starter
Hi Bob,
Following your instructions, the voltage at idle between sockets #16 and #4 is 6.7 volts, so it seems to be a faulty MAS. Hopefully it's in warranty and will be replaced. When I receive the replacement I'll let you know. Thanks for your patience in guiding me through the diagnosis.
Harry
Following your instructions, the voltage at idle between sockets #16 and #4 is 6.7 volts, so it seems to be a faulty MAS. Hopefully it's in warranty and will be replaced. When I receive the replacement I'll let you know. Thanks for your patience in guiding me through the diagnosis.
Harry
07-30-2019, 11:01 PM
#33
Junior Member
rebuiler in florida
I know this is going back a while does this rebuilder in Floria also do the HGS modules for R129 cars - I've one from a '90 SL300 I'd like looked at ? if so who are they so I can contact...
Hi Bob,
Well, I got the EZL back from the rebuilder in Florida, much delayed by hurricanes. I ran the tests you suggested. At the round diagnostic connector, X11, the voltage between terminals 2 and 3 is only 1.05 volts. The voltage on socket #1 of the electrical connector to the EZL is 12 volts. Could the rebuilt EZL still be defective? Are there other definitive tests I can run? I also connected a test light to terminal 1 (-) of the coil and ground. When the engine is cranked over the light does pulse. I then connected the voltmeter (+) to terminal 1 on the coil and the (-) to ground with a reading of 12 volts, which is supposed to indicate a shorted control wire or driver.
I've worked on cars as a hobby for many years and am not a complete dunce, but the problem with this car has overwhelmed me. Thanks for any help you may offer.
Harry
Well, I got the EZL back from the rebuilder in Florida, much delayed by hurricanes. I ran the tests you suggested. At the round diagnostic connector, X11, the voltage between terminals 2 and 3 is only 1.05 volts. The voltage on socket #1 of the electrical connector to the EZL is 12 volts. Could the rebuilt EZL still be defective? Are there other definitive tests I can run? I also connected a test light to terminal 1 (-) of the coil and ground. When the engine is cranked over the light does pulse. I then connected the voltmeter (+) to terminal 1 on the coil and the (-) to ground with a reading of 12 volts, which is supposed to indicate a shorted control wire or driver.
I've worked on cars as a hobby for many years and am not a complete dunce, but the problem with this car has overwhelmed me. Thanks for any help you may offer.
Harry
07-31-2019, 11:38 AM
#34
Junior Member
Thread Starter
