Fuel injectors not getting signal

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Danval
Posts: 87
Joined: Sat Dec 21, 2013 7:01 pm

Fuel injectors not getting signal

Post by Danval »

Gentlemen.
So, we have been trying to put a puzzle together. I bought this 79 530i from a guy, and it was a mess. One of the fuel lines was connected to one of the coolant ports in the head. That kind of a mess. So, we are going to use the car for a 1 time endurance race and we removed everything that has to do with the emissions system. The simpler the better because less systems that can fail at the race.
Now like the title says, I tested one of the connection for the injector and with a tester I'm not getting any signal.
Anyone can tell me or point me in some direction to start checking what might be the problem? Thanks a lot
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Robert Bondi
Posts: 338
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Location: Austin, TX

Post by Robert Bondi »

I'm confused on what you have. 1979 should be a 528i; 530i up through 1978. Are you getting a signal at any injector?
Robert
77 530i
77 Euro 528
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RonDwyer
Posts: 470
Joined: Sun Mar 01, 2009 7:01 pm
Location: San Francisco Bay Area

Post by RonDwyer »

I have a 528i computer and injection harness that I don't need. And a 530i computer.

The more you take off that car the simpler you can make it. Do you have an electrical schematic? Believe it or not, a Haynes manual is pretty good stuff. Electrical doesn't get to injectors if the box isn't even getting hot. There is a main relay you can test for output, or simply hotwire the box with suitable gauge wire. BTW: Dont do this without a schematic.

Is there a crankshaft reference sensor left on the engine? Little hall effect sensor pointing at the harmonic over by the distributor?

Electrical troubleshooting 101 - Find out where you have power and where you don't. Never trust a supposedly good ground unless you check it for corrosion. Wires in crimps get corroded.

Easy question, does it have an O2 sensor?

Ron
Ron Dwyer
Milwaukee, Wi

14 Audi A8L TDI
03 530i
08 F150 4X4
Danval
Posts: 87
Joined: Sat Dec 21, 2013 7:01 pm

Post by Danval »

Robert Bondi wrote:I'm confused on what you have. 1979 should be a 528i; 530i up through 1978. Are you getting a signal at any injector?
ive been getting that a lot. I thought i had a 1979 ( i was told) but the door tag says 530i. Im pretty sure its a 78 then. And no, im not getting signal to any injector.
Danval
Posts: 87
Joined: Sat Dec 21, 2013 7:01 pm

Post by Danval »

RonDwyer wrote:I have a 528i computer and injection harness that I don't need. And a 530i computer.

The more you take off that car the simpler you can make it. Do you have an electrical schematic? Believe it or not, a Haynes manual is pretty good stuff. Electrical doesn't get to injectors if the box isn't even getting hot. There is a main relay you can test for output, or simply hotwire the box with suitable gauge wire. BTW: Dont do this without a schematic.

Is there a crankshaft reference sensor left on the engine? Little hall effect sensor pointing at the harmonic over by the distributor?

Electrical troubleshooting 101 - Find out where you have power and where you don't. Never trust a supposedly good ground unless you check it for corrosion. Wires in crimps get corroded.

Easy question, does it have an O2 sensor?

Ron
i really
Dont see an o2 sensor. There is a magnet looking round pin on the harmonic balance, i just dont see a crank posición sensor on the braket. Also, can you please let me know where the main relay is located? I dont have a schematic for electronics. Is there anything online for e12 schematic? Thanks for your help guys
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RonDwyer
Posts: 470
Joined: Sun Mar 01, 2009 7:01 pm
Location: San Francisco Bay Area

Post by RonDwyer »

Then you likely have a 530i. It will have an air pump and large bulbous exhaust manifolds called Thermal Reactors, prehistoric smog stuff. Injectors not firing, have to do the basics and see if the control unit is getting power. Sometimes we get lucky. And, check the grounds. Trace the injection harness. BMW is spot-on with their color codes. Do you get any relays clicking when you turn on the key?



Feel free to give me a call 510-590-7369

https://www.bmwtechinfo.com/repair/main/057en/index.htm
Ron Dwyer
Milwaukee, Wi

14 Audi A8L TDI
03 530i
08 F150 4X4
centralcoaster
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Joined: Thu May 26, 2016 4:53 pm

Post by centralcoaster »

tis sounds a lot like the problem I was having with my 530i. the thread topic was ecu problems , posted a couple of weeks ago. Like you have been told, check out the wiring harness for the ecu and all of the sensors. if you have a good dual relay and all is well with your wiring harness, check pin #1 on the ecu harness located in the glove box. it should have a big plug and a separate wire which goes to a nearby spade connection probe the spade connector with a test light and try to start the car, there should be a pulse to the test light from the coil. If that isn't there then the injectors will not pulse either.
CBradio
Posts: 283
Joined: Fri Apr 06, 2012 12:03 am
Location: Brooklyn

Post by CBradio »

okay, first, you're confusing everybody here because we are pretty sure you have a 528i.

Second, I have a question: is everything okay with your distributor??

Are you sure nothing is disconnected there?

Also, are you getting a spark?
1977 530ia
Danval
Posts: 87
Joined: Sat Dec 21, 2013 7:01 pm

Post by Danval »

So, after trying several things. There is a wire that goes from the negative of the coil to pin #1 on ecu. It wasn't connected. As son as we jumped it, it started.
Thanks again everyone
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