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> Fuel injection issues....car down going on three months...help!, I have tested, broken, repaired many things but still nuthin'...
second wind
post May 28 2022, 02:02 PM
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Hello teener world....my fuel pump was having intermittent on/off issues and after messing up a few wires and swapping a few relays it seems to be consistently working now...new Optima battery didn't hurt things...still doesn't run and after a good three hour attack yesterday with seasoned 914'er figured out there is no gas coming out of the injectors.....plenty of pressure in the fuel rails but no spray out of the injectors. Got a pop or two after jiggling a few ground wires but all the ground wires seem to be nailed down down. The consensus is that it is either the wiring harness is messed up or the ECU may be bad. The wires have cracks in the plastic covering of course and everyone says that the ECU going bad is very rare....but possible. I would really appreciate your opinion on the subject and my car is a 1973 2.0 in case someone has a spare ECU on hand. Thank you very much and I need to get back on the road bad....I am only as happy as my car is running...I'm funny that way.
All the best,
Greg
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Geezer914
post May 28 2022, 02:29 PM
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If you are jiggling wires and getting a hit now and then, I would check the wire harness. Strip back the cracked dried up wire and replace it with new wire of the same guage. You are correct, the ECU's rarely go bad.
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mgphoto
post May 28 2022, 03:38 PM
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Rarely is not never, fuel pump never shuts off, big clue.
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rjames
post May 28 2022, 05:08 PM
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nothing in your description points to the ECU yet.
If you suspect bad wiring get a multimeter and check for continuity.
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mgphoto
post May 28 2022, 05:23 PM
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Here is another little clue, a noid light hooked up to cylinder #3 lights briefly when the key is turned on and does not flash as the engine is cranked.


That along with the fuel pump not stopping after 2 seconds with the key on.

Check resistance on the cylinder head sensor.
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second wind
post May 28 2022, 05:29 PM
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I did forget to mention prior to my current issue that when starting first thing in the morning the fuel pump will run for way more than two seconds....in fact I begin to start the car while the fuel pump is still going and the car will start just fine....then once warm when I turn the key to start the fuel pump with shut off in 2-3 seconds like it is supposed to and then I turn key to start and it starts just fine. I will keep thinking of additional clues. The wiring harness may have cracked insulation but the wire inside is still in there and functioning....correct? And a short will burn up something or blow a fuse....correct? The old harness can still function...right? I am all ears on any other thoughts....thank you again.
Greg
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mgphoto
post May 28 2022, 05:32 PM
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QUOTE(second wind @ May 28 2022, 04:29 PM) *

I did forget to mention prior to my current issue that when starting first thing in the morning the fuel pump will run for way more than two seconds....in fact I begin to start the car while the fuel pump is still going and the car will start just fine....then once warm when I turn the key to start the fuel pump with shut off in 2-3 seconds like it is supposed to and then I turn key to start and it starts just fine. I will keep thinking of additional clues. The wiring harness may have cracked insulation but the wire inside is still in there and functioning....correct? And a short will burn up something or blow a fuse....correct? The old harness can still function...right? I am all ears on any other thoughts....thank you again.
Greg

No fuses in the fi system. Low voltage electronics. A short will just change function, no burning wires unless shorted with high voltage.
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Lockwodo
post May 28 2022, 06:52 PM
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Make sure the trigger points are functional and plugged in to the wiring harness. If not, the fuel injection system won't work.
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JeffBowlsby
post May 28 2022, 08:45 PM
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QUOTE(second wind @ May 28 2022, 04:29 PM) *

I did forget to mention prior to my current issue that when starting first thing in the morning the fuel pump will run for way more than two seconds....in fact I begin to start the car while the fuel pump is still going and the car will start just fine....then once warm when I turn the key to start the fuel pump with shut off in 2-3 seconds like it is supposed to and then I turn key to start and it starts just fine. I will keep thinking of additional clues. The wiring harness may have cracked insulation but the wire inside is still in there and functioning....correct? And a short will burn up something or blow a fuse....correct? The old harness can still function...right? I am all ears on any other thoughts....thank you again.
Greg


You are making a number of significant assumptions, any one of which could be critical and cause the symptoms and faulty behaviors you are noting. It is clear that your harness is toast. In addition you may be having issues with other FI components. Each ones function can and should be fully verified.
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jim_hoyland
post May 28 2022, 09:11 PM
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New harness; when I replaced mine, we found a broken wire inside the casing. And, a replacemt is going to give you a ton of confidence; that is, until a new problem arises… (IMG:style_emoticons/default/biggrin.gif)
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second wind
post May 28 2022, 09:56 PM
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Thank you all...will continue tomorrow....how much $$$ is a new harness BTW?
Thank you very much!!
Greg
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emerygt350
post May 29 2022, 03:50 AM
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How do you feel about your trigger points? That would be where i would start. Ignore the other stuff untill you know they are functioning.
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Lockwodo
post May 29 2022, 05:22 AM
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QUOTE(emerygt350 @ May 29 2022, 02:50 AM) *

How do you feel about your trigger points? That would be where i would start. Ignore the other stuff untill you know they are functioning.

(IMG:style_emoticons/default/agree.gif)
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JeffBowlsby
post May 29 2022, 06:50 AM
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QUOTE(second wind @ May 28 2022, 08:56 PM) *

Thank you all...will continue tomorrow....how much $$$ is a new harness BTW?
Thank you very much!!
Greg


All avaibaility and pricing is on m harness website...scroll about 1/2 way down.

https://bowlsby.net/914/WiringHarnesses/

If you will PM me your zip code and email address I am happy to send you a full quote with shipping cost and payment details.
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Tjmrfe
post May 29 2022, 07:10 AM
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QUOTE(second wind @ May 28 2022, 12:02 PM) *

Hello teener world....my fuel pump was having intermittent on/off issues and after messing up a few wires and swapping a few relays it seems to be consistently working now...new Optima battery didn't hurt things...still doesn't run and after a good three hour attack yesterday with seasoned 914'er figured out there is no gas coming out of the injectors.....plenty of pressure in the fuel rails but no spray out of the injectors. Got a pop or two after jiggling a few ground wires but all the ground wires seem to be nailed down down. The consensus is that it is either the wiring harness is messed up or the ECU may be bad. The wires have cracks in the plastic covering of course and everyone says that the ECU going bad is very rare....but possible. I would really appreciate your opinion on the subject and my car is a 1973 2.0 in case someone has a spare ECU on hand. Thank you very much and I need to get back on the road bad....I am only as happy as my car is running...I'm funny that way.
All the best,
Greg

Greg,
Just recently I had my tank out, cause I was bored…and lo and behold, it was rubbing a fuel pump wire against the body! While nothing had come from it yet, I thought, damn…I dodged a bullet there. Just a thought, possibly I’m not the only one to have such an issue? Good luck.
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