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Electrical issues/ fuel injection

 
Old 01-07-2019, 12:14 AM
  #16  
Dylan_928
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Originally Posted by rjtw View Post
This is an L-jet? I agree with all the above advice and, if that doesn’t solve it, then replace the fuel injection relay.

The L-jet works by supplying 12v to the injectors full time and switching to ground for the duty cycle. So grounds are critical. And per your description, I and many others have had the exact same problem solved with a new relay (if ground cleaning doesn’t do it).
i bought a brand new relay and installed. There was a time after i put in the new relay that the car started up and ran fine. Then next morning i go to start the car and it wont stay running. I beleive it is just the grounds. Before i buy a new green wire i will clean all of the grounds asatga32 ( asatga32 as in as soon as temperatures go above 32). Thanks
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Old 01-07-2019, 02:05 PM
  #17  
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Originally Posted by Mrmerlin View Post
Joe the green wire gets the signal from the distributor signal fingers think early electronic ignition systems.
The MAF systems then went to having a reference sensor timed to the flywheel.
Thank you Stan.

My 944 has a version of L-Jet, with a "Barn Door" AFM. But it runs a DME brain box, where both the spark timing and FI pulse are regulated. It runs a crank sensor (two actually) that are essential for the car to run. It's kind of funny how some stuff crosses over from the 928 to the 944, but only some of it.

Dylan - Don't screw around. Get a new Green Wire and forget about it for a while. Its not cheap, but if you want to own and drive a 928, you will have to get used to the idea that the car was the Porsche Flagship when new. It cost the equivalent of a small to medium sized house when new. Parts cost will reflect that number, not what you paid for it. Qualified labor will also cost, but you can do almost everything yourself if you wish. As you are finding out, there's folks on here that are willing to offer advice & assistance. Stan (MrMerlin) and Sean (SeanR) both turn wrenches on these things for a living.

Also, you are missing the jump post cap & cover. The little '****' along the right side fender, just behind the radiator (almost touching the radiator hose in your pic) is 12v positive. It's hot all the time. Anything touching it to ground will create a pretty spark show and lots of smoke. Putting the smoke back into the wires and components gets expensive fast.

There is a cap that goes over it. There is also a boxy cover that goes over the whole assembly. The big plug right there is called the '14 pin plug' (because it has 14 pins - we aren't all that complicated here ). It is the main plug for the engine harness. Everything runs through it. The cover keeps rain water from dripping on it.

Both cap & cover are fairly important. Both are often missing. Roger carries them for something like $15 for both. Its one of the few things that won't cost an arm and a leg, but really should be there.
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Old 01-07-2019, 02:22 PM
  #18  
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Oh, and also (warning - old guy rant coming) -

What is wrong with you ding-dongs on here?

New guy, new car, 17 posts and we haven't gone beyond...

THREAD IS...

sheesh.
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Old 01-07-2019, 02:26 PM
  #19  
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WORTHLESS WITHOUT
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Old 01-07-2019, 03:39 PM
  #20  
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Originally Posted by Wisconsin Joe View Post
Thank you Stan.

My 944 has a version of L-Jet, with a "Barn Door" AFM. But it runs a DME brain box, where both the spark timing and FI pulse are regulated. It runs a crank sensor (two actually) that are essential for the car to run. It's kind of funny how some stuff crosses over from the 928 to the 944, but only some of it.

Dylan - Don't screw around. Get a new Green Wire and forget about it for a while. Its not cheap, but if you want to own and drive a 928, you will have to get used to the idea that the car was the Porsche Flagship when new. It cost the equivalent of a small to medium sized house when new. Parts cost will reflect that number, not what you paid for it. Qualified labor will also cost, but you can do almost everything yourself if you wish. As you are finding out, there's folks on here that are willing to offer advice & assistance. Stan (MrMerlin) and Sean (SeanR) both turn wrenches on these things for a living.

Also, you are missing the jump post cap & cover. The little '****' along the right side fender, just behind the radiator (almost touching the radiator hose in your pic) is 12v positive. It's hot all the time. Anything touching it to ground will create a pretty spark show and lots of smoke. Putting the smoke back into the wires and components gets expensive fast.

There is a cap that goes over it. There is also a boxy cover that goes over the whole assembly. The big plug right there is called the '14 pin plug' (because it has 14 pins - we aren't all that complicated here ). It is the main plug for the engine harness. Everything runs through it. The cover keeps rain water from dripping on it.

Both cap & cover are fairly important. Both are often missing. Roger carries them for something like $15 for both. Its one of the few things that won't cost an arm and a leg, but really should be there.
thanks so much for all of your help joe! I will get a green wire as soon as i can, and i may sound stupid by saying this, but what is Roger?
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Old 01-07-2019, 03:51 PM
  #21  
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Roger at 928's R Us, http://www.928srus.com/

...and just to complete the saying:
PICS!

Pictures of the project car, please!
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Old 01-07-2019, 04:00 PM
  #22  
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Originally Posted by Hey_Allen View Post
Roger at 928's R Us, http://www.928srus.com/

...and just to complete the saying:
PICS!

Pictures of the project car, please!
awesome! And i will be sure to get pics uploaded after school! ))
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Old 01-07-2019, 04:50 PM
  #23  
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Here are some pics
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Old 01-07-2019, 04:53 PM
  #24  
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I guess my pictures wont upload... ill try later tonight
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Old 01-07-2019, 07:19 PM
  #25  
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Anybody know what this wire is for???




Like i said, she is rough. I have most everything fir interior and i also have all the trim pieces and the passenger flooring. I also got the complete tool kit to go with it
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Old 01-07-2019, 07:33 PM
  #26  
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I'm making a complete guess here but I don't recognize that line and it doesn't look original, could it be an antenna connection for the radio?
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Old 01-07-2019, 08:13 PM
  #27  
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best to service the CE panel,
from the start your missing relays,
and you have too many fuses installed.
Google whatever year your car is and fuse panel diagram, rennlist ,see what happens
NOTE some fuse slots should be empty as well as some of the relay slots.
adding fuses to slots that should be empty can back power systems that shouldnt be powered,
this can cause power drains and other starting issues .
Same can be said for the relays
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Old 01-07-2019, 08:26 PM
  #28  
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Yeah, it 'needs some TLC', but that's not important.

Full tool kit is pretty cool. And unusual. Any of the other 'goodies' from back there? Tire inflator, gloves, bulb kit, anything like that?

No clue what that coax is. I don't think it's factory. Perhaps an 80s era phone antenna.

As was noted, your CE panel (CE = Central electrical - what the fuse & relay panel is called) is not right. It's pretty important to have fuses where they belong, and NOT where they don't belong.

As with just about everything on these cars, the correct layout has been documented.
Here:

https://rennlist.com/forums/928-foru...all-years.html
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Old 01-07-2019, 10:12 PM
  #29  
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Originally Posted by Wisconsin Joe View Post
Yeah, it 'needs some TLC', but that's not important.

Full tool kit is pretty cool. And unusual. Any of the other 'goodies' from back there? Tire inflator, gloves, bulb kit, anything like that?

No clue what that coax is. I don't think it's factory. Perhaps an 80s era phone antenna.

As was noted, your CE panel (CE = Central electrical - what the fuse & relay panel is called) is not right. It's pretty important to have fuses where they belong, and NOT where they don't belong.

As with just about everything on these cars, the correct layout has been documented.
Here:

https://rennlist.com/forums/928-foru...all-years.html
Only other items i have is the spare tire. I will be relocating fuses and relays into the spots they need to be in also


Cap is in need of replacement as well

“Green wire” needs replacement

Rotor isnt terrible but i will be replacing
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Old 01-07-2019, 11:21 PM
  #30  
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NOTE only buy Bosch electrical parts for your car
Cap, Rotor, ALT regulator,
or Paris Rhone regulator depends on what ALT you have
The cap and rotor you posted are not Bosch
Get Beru plug and play ignition wires
Get Bosch silver tip plugs PN 7900 at autozone 1.99 each
get good relays from one of our vendors.
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