1987 Carrera won’t start
10-08-2018, 12:46 PM
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1987 Carrera won’t start
Drove car to PCA event, parked car before club run (20 minutes), attempted start to begin run and car wouldn’t start. Conditions were cloudy, slight drizzle and cool temps (12-15 C). On initial crank before run, engine ignited momentarily and then died slowly. Attempted starting for the next couple of minutes, when finally she started. Ran fine throughout event until last stop when I turned her off (15-20 minutes). It was raining and attempted for an hour to crank, no luck. Got vehicle hauled to home and attempted next morning, with no luck. Car cranks strong, new battery, where do I start?
10-08-2018, 01:16 PM
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1987 Carrera won’t start
This is my first post and wish to thank all beforehand for any help given. Drove car to PCA CWR event, parked car before club run (20 minutes), attempted start to begin run and car wouldn’t start. Conditions were cloudy, slight drizzle and cool temps (12-15 C). On initial crank before run, engine ignited momentarily and then died slowly. Attempted starting for the next couple of minutes, when finally she started. Ran fine throughout event until last stop when I turned her off (15-20 minutes). It was raining and attempted for an hour to crank, no luck. Got vehicle hauled to home and attempted next morning, with no luck. Car cranks strong, installed new battery two weeks ago, have fuel, where do I start?
10-08-2018, 02:22 PM
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Drove car to PCA event, parked car before club run (20 minutes), attempted start to begin run and car wouldn’t start. Conditions were cloudy, slight drizzle and cool temps (12-15 C). On initial crank before run, engine ignited momentarily and then died slowly. Attempted starting for the next couple of minutes, when finally she started. Ran fine throughout event until last stop when I turned her off (15-20 minutes). It was raining and attempted for an hour to crank, no luck. Got vehicle hauled to home and attempted next morning, with no luck. Car cranks strong, new battery, where do I start?
Your description of wet weather seems to imply you feel you may have a wet ignition issue. A quick test for this is to wet down the ignition wired with a little spray oil lube to displace the moisture and see if it starts. Unlikely your wires are that bad. Another way to test the wires is to start the car at night and observe sparks leaking from the wires in the dark. Again highly unlikely as you would also probably trip multiple misfire Diagnostic codes and your dash light would be illuminated if your wires were bad enough to thwart starting. Finally, consider running your car's Diagnostic codes with a code reader.
ANdy
Spare DME Relay
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10-08-2018, 05:03 PM
#8
99% of the time it is the DME relay. A known long-term weakness where an internal solder joint fails from vibration. Replace it and pop open and solder fix your old one as a spare to be stored in the glove box.
Your description of wet weather seems to imply you feel you may have a wet ignition issue. A quick test for this is to wet down the ignition wired with a little spray oil lube to displace the moisture and see if it starts. Unlikely your wires are that bad. Another way to test the wires is to start the car at night and observe sparks leaking from the wires in the dark. Again highly unlikely as you would also probably trip multiple misfire Diagnostic codes and your dash light would be illuminated if your wires were bad enough to thwart starting. Finally, consider running your car's Diagnostic codes with a code reader.
ANdy
Spare DME Relay
Your description of wet weather seems to imply you feel you may have a wet ignition issue. A quick test for this is to wet down the ignition wired with a little spray oil lube to displace the moisture and see if it starts. Unlikely your wires are that bad. Another way to test the wires is to start the car at night and observe sparks leaking from the wires in the dark. Again highly unlikely as you would also probably trip multiple misfire Diagnostic codes and your dash light would be illuminated if your wires were bad enough to thwart starting. Finally, consider running your car's Diagnostic codes with a code reader.
ANdy
Spare DME Relay
20+ years life span for a car part, is a very robust design, IMHO!
DME/ECM relay is aka fuel pump relay
10-08-2018, 07:15 PM
#9
Three Wheelin'
Sounds like a DME relay.
10-09-2018, 03:01 AM
#10
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Assuming you didn’t smell fuel while cranking?
http://www.911chips.com/dmerelay.html
Hes got a later g body. Dme relay is under driver seat. Assuming you have left hand drive. It powers the computer and fuel pump. Super common. Also chec fuse #6 fuel pump
https://www.rmeuropean.com/Products/...G504-V814.aspx
http://www.911chips.com/dmerelay.html
Hes got a later g body. Dme relay is under driver seat. Assuming you have left hand drive. It powers the computer and fuel pump. Super common. Also chec fuse #6 fuel pump
https://www.rmeuropean.com/Products/...G504-V814.aspx
10-09-2018, 05:10 AM
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Check the crankshaft sensors
My 1985 did not start because the cranshaft position sensor was bad. Check them. Don’t remove the bracket, just the sensor if you need to replace so distance to flywheel is OK.
The sensors was a lot cheaper as BMW sensors at least here.
Porsche 911.606.215.01 (Bosch 0 261 210 005) can be replaced ewih BMW 12 14 1 708 619 (Bosch 0 261 210 002)
Difference is in cable length.
Here a troubleshooting site:
http://www.hiperformancestore.com/Motronic.htm
Juha
Finland
The sensors was a lot cheaper as BMW sensors at least here.
Porsche 911.606.215.01 (Bosch 0 261 210 005) can be replaced ewih BMW 12 14 1 708 619 (Bosch 0 261 210 002)
Difference is in cable length.
Here a troubleshooting site:
http://www.hiperformancestore.com/Motronic.htm
Juha
Finland
10-10-2018, 01:26 PM
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Suggest you check also the DME unit. Open it and check the soldered joints. If you see a grey circle it
can be a cracked solder. Someone, if not you, handy with a soldering iron could re-solder all joints. This is
old fashioned full size electronics and usually don't fail, but the soldering does. Don't rush and buy a new
expensive DME unit before you have checked this. Apologize for my explanation, I'm not native English.
can be a cracked solder. Someone, if not you, handy with a soldering iron could re-solder all joints. This is
old fashioned full size electronics and usually don't fail, but the soldering does. Don't rush and buy a new
expensive DME unit before you have checked this. Apologize for my explanation, I'm not native English.
10-22-2018, 01:51 AM
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still wont start
Sorry for not replying sooner, have been chasing the rabbit down the hole. First, thanks for all the replies. I have changed the DME relay to no avail. After that, I checked the coil (12.7V, 1+15 =.5 to .6 ohms, 4+15 = 5.65 ohms). Next, I checked for spark, got none. On to the injectors and while cranking got no clicking of the injectors. I then went to the DG/BG speed/reference sensors in the engine bay and tested with my multi-meter. On the DG and BG connectors (Speed/Reference sensors), the 1-2 probe read 934/997 ohms, on the 1-3 and 2-3 probes I got nothing, no reading whatsoever on either sensor. I was supposed to read >100,000 ohms, but got OL in the window. I have a Southwire 16040T multimeter and have been told by the manufacturer that it will auto-set. I ordered two new sensors and received them tonight Used meter on them and got the same results as the two in the car. I'm at a lose and am not sure what to do next. My plan is to replace the old sensors with the new and just see what happens. If that doesn't work I then may send off the DME controller to a rebuild shop and see whats up. Any further help would be greatly appreciated.
10-22-2018, 01:53 AM
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Sorry for not replying sooner, have been chasing the rabbit down the hole. First, thanks for all the replies. I have changed the DME relay to no avail. After that, I checked the coil (12.7V, 1+15 =.5 to .6 ohms, 4+15 = 5.65 ohms). Next, I checked for spark, got none. On to the injectors and while cranking got no clicking of the injectors. I then went to the DG/BG speed/reference sensors in the engine bay and tested with my multi-meter. On the DG and BG connectors (Speed/Reference sensors), the 1-2 probe read 934/997 ohms, on the 1-3 and 2-3 probes I got nothing, no reading whatsoever on either sensor. I was supposed to read >100,000 ohms, but got OL in the window. I have a Southwire 16040T multimeter and have been told by the manufacturer that it will auto-set. I ordered two new sensors and received them tonight Used meter on them and got the same results as the two in the car. I'm at a lose and am not sure what to do next. My plan is to replace the old sensors with the new and just see what happens. If that doesn't work I then may send off the DME controller to a rebuild shop and see whats up. Any further help would be greatly appreciated.