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| mepstein |
Aug 13 2017, 12:20 PM
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#1
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914-6 GT in waiting ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 20,218 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region
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I can't get my fuel pump to run unless I jumper the plug for the DME relay. The car starts and runs with the connection jumped but the fuel pump then runs all the time. Just want to know where to look and what to do.
I'm very electrically challenged so you might need to really dumb it down for me. Thanks |
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| Steve |
Aug 13 2017, 09:24 PM
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#2
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914 Guru ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 5,959 Joined: 14-June 03 From: Laguna Niguel, CA Member No.: 822 Region Association: Southern California
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Do what Spoke suggested and put an ohm Meter on pin 20 of the dme. It should be grounded while cranking the starter. If it's not then something else connected to the DME is causing the problem. Have to troubleshoot each sensor / inputs on the DME to figure it out. I have had lots of interesting problems with my injection that I used the Bentley manual to trouble shoot.
Motor won't start after installing for the first time - turns out it was a pinched fuel line under tank which doubled the fuel pressure Car sat for 3 years and wouldn't start (rustoration) -Pelican guy's on there 911 forum recommended unplugging the injectors one at a time. After unplugging the last one it started and ran on 5 cylinders. Shut motor off and plugged it back in and now it runs fine on all six cylinders for over two years now. The flywheel sensors are also known causing no start issues. Some people replace them and get rebuilt injectors when they overhaul the engine. Otherwise mine runs great and I have not had any problems besides the above. Not bad for 33 year old original motor with a bazillion miles on it!! |
| mepstein |
Aug 13 2017, 09:46 PM
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#3
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914-6 GT in waiting ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 20,218 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region
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Do what Spoke suggested and put an ohm Meter on pin 20 of the dme. It should be grounded while cranking the starter. If it's not then something else connected to the DME is causing the problem. Have to troubleshoot each sensor / inputs on the DME to figure it out. I have had lots of interesting problems with my injection that I used the Bentley manual to trouble shoot. Motor won't start after installing for the first time - turns out it was a pinched fuel line under tank which doubled the fuel pressure Car sat for 3 years and wouldn't start (rustoration) -Pelican guy's on there 911 forum recommended unplugging the injectors one at a time. After unplugging the last one it started and ran on 5 cylinders. Shut motor off and plugged it back in and now it runs fine on all six cylinders for over two years now. The flywheel sensors are also known causing no start issues. Some people replace them and get rebuilt injectors when they overhaul the engine. Otherwise mine runs great and I have not had any problems besides the above. Not bad for 33 year old original motor with a bazillion miles on it!! Remember, i did say my car starts, I need to figure out why the fuel pump wont run unless I remove the dme relay and jump it with a wire. But I will follow all the advise you guys have given me and report back. As always, I appreciate the help. |
mepstein Need 3.2 conversion electrical help Aug 13 2017, 12:20 PM
Steve You did try another dme relay? Otherwise the Bent... Aug 13 2017, 01:06 PM
Spoke I had a similar problem on my 930. Engine would ru... Aug 13 2017, 01:21 PM
mepstein Tried 4 new relays. One was solid state.
Flummoxe... Aug 13 2017, 01:30 PM
Spoke
Tried 4 new relays. One was solid state.
Flummox... Aug 13 2017, 02:04 PM
porschetub The solder joints can also fail on them too,pop th... Aug 13 2017, 01:36 PM
mepstein
The solder joints can also fail on them too,pop t... Aug 13 2017, 01:45 PM
Spoke
I jumper the plug for the DME relay.
Which pins... Aug 13 2017, 02:11 PM
Spoke Some tests with your voltmeter:
put a small wire ... Aug 13 2017, 02:14 PM
Steve This manual is awesome!!
Aug 13 2017, 03:34 PM
Steve RE: Need 3.2 conversion electrical help Aug 13 2017, 03:36 PM
Steve RE: Need 3.2 conversion electrical help Aug 13 2017, 03:42 PM
jim912928 I hate wiring...do you have the red wire (fuel pum... Aug 13 2017, 06:38 PM
mepstein
I hate wiring...do you have the red wire (fuel pu... Aug 13 2017, 06:42 PM
Spoke Looks like a pretty simple circuit:
1) Ignition k... Aug 13 2017, 07:20 PM
mepstein I know the dme is good. Runs fine in other cars. Aug 13 2017, 08:30 PM
shoguneagle Do not over look the DME Relay socket itself; shor... Aug 13 2017, 10:02 PM
McMark If you've tried the DME in other cars and they... Aug 14 2017, 07:02 AM
jim912928 The AFM point is a good one. Before I put my 3.2l ... Aug 16 2017, 05:30 PM
Spoke Mark and Ray stopped by my house today to do some ... Aug 19 2017, 09:27 PM
timothy_nd28
Things to do to finish the install:
1) Figure out... Aug 22 2017, 09:12 AM
mepstein Huge step to have the engine start with the turn o... Aug 20 2017, 08:08 AM
Cairo94507 Glad to hear you resolved that issue and will be d... Aug 20 2017, 08:23 AM
jim912928 congrats! Aug 20 2017, 10:24 AM![]() ![]() |
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