So mostly likely you are not getting power to the dme. Relay, ignition key, alarm, etc.whalenlg wrote: Fri May 23, 2025 10:43 pm Boost gauge stays stuck all the way left even when cranking.
No Start + Jolt?
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Tom
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Did you remove the bellhousing ground for the clutch work by any chance?
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Tom
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On a non-Porsche, I once had a ground cable get pinched between metal when the engine was reinstalled -- took a while to show symptoms... In your case, I'd check for power and ground at the 35 pin DME connector, and work backwards from the connectors if there is none (which it sounds like there isn't). You can borrow a DME relay if helpful, or whatever else might help...
DME grounds and power from the relay look good.
Pin 20 of the open connector pulls to 12V when turning the key to ON, but that's likely due to no connection to the DME.
Looks like I need to swap the DME tomorrow.
Didn't check speed or ref sensors so far.
Pin 20 of the open connector pulls to 12V when turning the key to ON, but that's likely due to no connection to the DME.
Looks like I need to swap the DME tomorrow.
Didn't check speed or ref sensors so far.
1986 951 - Silicon Valley
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Tom
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Did you check for power at the 35pin DME connector? And at the KLR for that matter? With the key turned to the on position, the boost gauge should go to 1 if the KLR has power.
Yes - there’s power on the dme connector pins from the dme relay.
Didn’t check the klr connector yet, but it’s not clear which pin is power from the pin outs I’ve seen. Will need to dig into the schematics. Possibly a pass through from the dme.
Didn’t check the klr connector yet, but it’s not clear which pin is power from the pin outs I’ve seen. Will need to dig into the schematics. Possibly a pass through from the dme.
1986 951 - Silicon Valley
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Tom
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Power is Pin 6 on the KLR connector, they just call it "U (sheet)" to keep you guessing. If the KLR has power, then the lack of boost gauge movement might be a clue... to something...?
I saw your original question on RL (and answer) - time flies, but Tom never forgets!
KLR pin 6 gets 12v when I turn to ON
I get good ground connections on KLR Pins 14 and 20 (main ground)
I decided to swap in my non turbo spare DME - started right up. But no boost gauge action (but again - its a non turbo DME, so the KLR is probably not getting any inputs from the non turbo DME).
Only obvious conclusion is that the DME is bad unless there's some other explanation.
KLR pin 6 gets 12v when I turn to ON
I get good ground connections on KLR Pins 14 and 20 (main ground)
I decided to swap in my non turbo spare DME - started right up. But no boost gauge action (but again - its a non turbo DME, so the KLR is probably not getting any inputs from the non turbo DME).
Only obvious conclusion is that the DME is bad unless there's some other explanation.
1986 951 - Silicon Valley