 1973 Porsche 1.7 D-Jet, No power to two injectors |
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| crodog |
 Apr 30 2017, 08:38 AM
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#1
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Newbie  Group: Members Posts: 4 Joined: 19-March 17 From: Wisconsin Member No.: 20,942 Region Association: None  |
I have power to #3 and #4 injectors but not #1 and #2. The car will run but it is missing on 1 & 2. I have spark but when I pull the wires off the injectors nothing happens. After testing more I found I have no power to both of them. Where does the power come from? Do I need to look at the releasing contacts at the base of the distributor?
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| Dave_Darling |
Apr 30 2017, 12:44 PM
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#2
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914 Idiot Group: Members Posts: 15,000 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California 
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Power to the injectors comes from the ECU. The trigger points in the base of the distributor tell the ECU when to send power to the injectors. They do that in two "batches", but those are #1/#3, and #2/#4. They are diagonally across the engine from each other, not on the same side.
If the trigger points are to blame, something is funky with your wiring. I would start by re-checking that you are actually getting pulses of power to those two injectors while the engine is cranking over. If not, then I would suspect the wiring. --DD |
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| larss |
Apr 30 2017, 10:56 PM
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#3
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Member Group: Members Posts: 428 Joined: 10-September 09 From: Sweden Member No.: 10,787 Region Association: Scandinavia |
QUOTE(Dave_Darling @ Apr 30 2017, 07:44 PM)  Power to the injectors comes from the ECU. The trigger points in the base of the distributor tell the ECU when to send power to the injectors. They do that in two "batches", but those are #1/#3, and #2/#4. They are diagonally across the engine from each other, not on the same side. ....... --DD Dave, Not sure here bud looking at the electronic diagram below it seems like terminal 3 and 4 (upper right corner) in the ECU share the same output transistor. Terminal 3 and 4 should be for injectors 1 and 4 respectively (see öower wiring diagram) and if I am right in this they are forced to fire simultaneously. Lars S (IMG:http://www.914world.com/bbs2/uploads_offsite/www.pelicanparts.com-10787-1493614597.1.jpg) (IMG:http://www.914world.com/bbs2/uploads_offsite/www.pelicanparts.com-10787-1493614598.2.jpg) |
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Posts in this topic
crodog 1973 Porsche 1.7 D-Jet Apr 30 2017, 08:38 AM
larss No1 and 2 have a common spade connector fort earth... Apr 30 2017, 10:57 AM crodog Thx for the info. I will hunt down the grounds. Ma... Apr 30 2017, 11:03 AM
larss
Thx for the info. I will hunt down the grounds. M... Apr 30 2017, 11:14 AM CatDaddy60 I agree that most likely it is a ground issue as t... Apr 30 2017, 12:11 PM crodog
Power to the injectors comes from the ECU. The t... Apr 30 2017, 01:55 PM bdstone914
Power to the injectors comes from the ECU. The ... Apr 30 2017, 02:00 PM Jeff Bowlsby Actually the injector groups as the ECU see them a... Apr 30 2017, 11:07 PM larss
Actually the injector groups as the ECU see them ... May 1 2017, 12:41 AM Jeff Bowlsby I could be wrong, its been years since I read thes... May 1 2017, 08:07 AM larss Below from the Robert Bosch 914 D-jet manual.
The ... May 1 2017, 08:21 AM Dave_Darling Yes, the injectors are opened in two batches. I h... May 1 2017, 09:06 AM larss Agree Dave, I just used a cheap test lamp with LED... May 1 2017, 09:53 AM |
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