Trying to start my carbureted 1.7, Electrical help |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Trying to start my carbureted 1.7, Electrical help |
pastormacman |
Nov 12 2019, 08:21 AM
Post
#21
|
Newbie Group: Members Posts: 28 Joined: 6-July 05 From: Bakersfield, CA Member No.: 4,382 |
Is the pump connected to the original wires? Not at this time. The black wire is spliced to a wire going to a ground point on the car. The red wire is spliced to a wire running up to the coil. I took that wire from the coil and connected it to the hot on the battery using a test light. The test light came on but the pump didn’t start. I have found the original wires, the connector has been cut off and is gone. Once I get a fuel pump that works, I’ll attach it to the original wires and patch the relay board as shown in SirAndys diagram. |
jcd914 |
Nov 12 2019, 10:01 AM
Post
#22
|
Advanced Member Group: Members Posts: 2,081 Joined: 7-February 08 From: Sacramento, CA Member No.: 8,684 Region Association: Northern California |
Is the pump connected to the original wires? Not at this time. The black wire is spliced to a wire going to a ground point on the car. The red wire is spliced to a wire running up to the coil. I took that wire from the coil and connected it to the hot on the battery using a test light. The test light came on but the pump didn’t start. I have found the original wires, the connector has been cut off and is gone. Once I get a fuel pump that works, I’ll attach it to the original wires and patch the relay board as shown in SirAndys diagram. Your test light won't pass enough current to run the fuel pump. Replace your test light with an inline fuse and test your pump again. In the test you describe the light bulb limits the current flow to the pump and the pump won't run but the light will work. An inline fuse will protect your wiring in case the pump has a dead short. Jim |
pastormacman |
Nov 12 2019, 10:25 AM
Post
#23
|
Newbie Group: Members Posts: 28 Joined: 6-July 05 From: Bakersfield, CA Member No.: 4,382 |
Your test light won't pass enough current to run the fuel pump. Replace your test light with an inline fuse and test your pump again. In the test you describe the light bulb limits the current flow to the pump and the pump won't run but the light will work. An inline fuse will protect your wiring in case the pump has a dead short. Jim That's very good to know, I didn't know that. I'll get the proper wiring and test it again. This forum has been so helpful and I appreciate all the help I've been getting and how quickly everyone responds. |
rhodyguy |
Nov 12 2019, 10:58 AM
Post
#24
|
Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,198 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
The plug end of the stock pump harness will have dif connectors. Make up a pig tail that works with the replacement pump. The relay board trick and start tracking circuits. Remove the coil from equation.
Is the facet mounted to the bottom of the engine shelve? Is that a J tube hole above it? |
pastormacman |
Nov 12 2019, 02:13 PM
Post
#25
|
Newbie Group: Members Posts: 28 Joined: 6-July 05 From: Bakersfield, CA Member No.: 4,382 |
Is the facet mounted to the bottom of the engine shelve? Is that a J tube hole above it? Yes it's mounted to the bottom underside of the "hell hole" I'm not sure what the J tube is. Is it the tube to drain the water from the engine lid? I think that might be it. My drainage tubes all disintegrated over time and are no longer there. |
ndfrigi |
Nov 12 2019, 02:19 PM
Post
#26
|
Advanced Member Group: Members Posts: 2,960 Joined: 21-August 11 From: Orange County Member No.: 13,474 Region Association: Southern California |
Is the facet mounted to the bottom of the engine shelve? Is that a J tube hole above it? Yes it's mounted to the bottom underside of the "hell hole" I'm not sure what the J tube is. Is it the tube to drain the water from the engine lid? I think that might be it. My drainage tubes all disintegrated over time and are no longer there. Is the circled one you are referring too? that is the hole where the fuel pump wire coming from and should have a rubber gromet. |
pastormacman |
Nov 12 2019, 02:45 PM
Post
#27
|
Newbie Group: Members Posts: 28 Joined: 6-July 05 From: Bakersfield, CA Member No.: 4,382 |
Is the circled one you are referring too? that is the hole where the fuel pump wire coming from and should have a rubber gromet. I assumed that was the hole you were referring to. I'm not home right now so I can't take a look at it to confirm. By my memory I assumed it was the drainage hole, but it probably is the access hole for the Fuel pump wiring. The connector and the rubber grommet are no longer on the wiring. The wiring is currently still up in the engine bay cut bare. I will eventually run them back down the access hole and crimp them to the red and black wires coming off the fuel pump, so that it's all running through the original wiring loom. |
ndfrigi |
Nov 12 2019, 03:25 PM
Post
#28
|
Advanced Member Group: Members Posts: 2,960 Joined: 21-August 11 From: Orange County Member No.: 13,474 Region Association: Southern California |
Is the circled one you are referring too? that is the hole where the fuel pump wire coming from and should have a rubber gromet. I assumed that was the hole you were referring to. I'm not home right now so I can't take a look at it to confirm. By my memory I assumed it was the drainage hole, but it probably is the access hole for the Fuel pump wiring. The connector and the rubber grommet are no longer on the wiring. The wiring is currently still up in the engine bay cut bare. I will eventually run them back down the access hole and crimp them to the red and black wires coming off the fuel pump, so that it's all running through the original wiring loom. |
pastormacman |
Dec 7 2019, 02:58 PM
Post
#29
|
Newbie Group: Members Posts: 28 Joined: 6-July 05 From: Bakersfield, CA Member No.: 4,382 |
Ok. Been busy with work but was able to work on the car recently. I got a regular alligator clip test cable and tested the red wire from the fuel pump to the hot on the battery and low and behold, I heard the fuel pump kick on.
So I went ahead and rewired the pump back into the original wiring harness (Black/red to red and brown to black). I also created the jumper wire from pin one to ground as Andy's tutorial says. I turned the key and... NOTHING. Fuel pump does not turn on. Did I miss something? |
pastormacman |
Dec 7 2019, 03:16 PM
Post
#30
|
Newbie Group: Members Posts: 28 Joined: 6-July 05 From: Bakersfield, CA Member No.: 4,382 |
So I decided to test the connection by pushing a probe into the black/red side of the crimp connector going to the red fuel pump wire. And I touched the hot on the battery and current ran through the connection and the fuel pump came on. So I know the connection is good.
However, something else is troubling me. I let the fuel pump run for 20-30 seconds but no fuel showed up in the upper fuel filter between the carbs. I can see fuel in the lower filter but it's not full. Should it be full? I've got about 2-3 gallons of fuel in the tank and I can see fuel in the tank when I shine a light in it. Any idea why fuel isn't making it to the upper fuel filter? |
rhodyguy |
Dec 7 2019, 04:13 PM
Post
#31
|
Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,198 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
The 2 fuses on the relay board are filthy. Clean the board. Clean the fuse tangs. Clean or replace the fuses. Check fuses for continuity.
|
pastormacman |
Dec 7 2019, 11:43 PM
Post
#32
|
Newbie Group: Members Posts: 28 Joined: 6-July 05 From: Bakersfield, CA Member No.: 4,382 |
Are there any fuses or relays under the dash that I need to check? I've checked continuity on the fuses on the relay board and they are good. But I will clean it all to be safe.
|
porschetub |
Dec 8 2019, 01:33 PM
Post
#33
|
Advanced Member Group: Members Posts: 4,761 Joined: 25-July 15 From: New Zealand Member No.: 18,995 Region Association: None |
No none to worry about in that area,have you checked the voltage to the pump when its powered....it may not be a full 12volts,I don't know if the Facets are voltage dependant but some others are,some Bosch pumps don't preform well with low voltage for example.
If you remove the inlet to your filter you should have fuel flow ,if not you may have a blocked tank suction filter. Try not to use screw hose clips (as mentioned) and try to avoid those open crimp joiners,use Duraseals or solder and heatshrink . Good luck. |
SirAndy |
Dec 8 2019, 02:28 PM
Post
#34
|
Resident German Group: Admin Posts: 41,957 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
Did you check the fuel pump relay? Your relay board looks very dirty. You can remove the plastic cap from the relay and measure/test to make sure the relay works as intended.
As always, follow the current. From the forward connector through the fuse, through the relay, to the pump. (IMG:style_emoticons/default/idea.gif) |
Spoke |
Dec 8 2019, 10:23 PM
Post
#35
|
Jerry Group: Members Posts: 7,106 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
You can test the relays involved with providing the power to the fuel pump.
Check out the relay board layout below. Notice the POWER SUPPLY relay in the middle of the board. This relay provides power to the ECU (not installed) and the relay to power the fuel pump. Turning the key to ON will power the Power Supply relay. You can check this switched voltage at the ECU connector. See the wire leaving the Power Supply relay pin 87. This is switched power. It goes to Fuel Pump Relay pin 85 and ECU pin I. To test the Power Supply relay, first remove the connector to the engine. This will keep the coil/points/Pertronix from overheating as you debug the fuel pump issue. Also we need access to pin 12. After the connector to the engine is removed, turn the ignition key to ON. This will cause the Power Supply Relay to turn on and provide 12V to pin I of the ECU plug. With your voltmeter, measure pin I to chassis. You should see 12V. If you do, then the Power Supply relay is good. Once the Power Supply relay is tested good, then check the output of the Fuel Pump relay. Power to the fuel pump comes from the 25A fuse on the relay board. Check the voltage on both sides of the fuse. Check the fuse holder, not the fuse for power. You should see 12V on both sides. Once the 25A fuse is tested ok, with ignition key still on, notice the voltage to the fuel pump comes from Fuel Pump relay pin 87. Follow that wire upwards to the 14-pin connector to the cabin and fuel pump. You cannot measure the voltage there as the connector is still on. However, follow the wire from Fuel Pump relay pin 87 DOWN the page then over to the right to the connector to the engine. You've already removed this connector. Thus the fuel pump voltage from the relay can be measured on pin 12. Let us know what you find. Attached thumbnail(s) |
IronHillRestorations |
Dec 9 2019, 06:51 AM
Post
#36
|
I. I. R. C. Group: Members Posts: 6,793 Joined: 18-March 03 From: West TN Member No.: 439 Region Association: None |
Make sure the fuel hose isn't kinked, it's easy to do
|
Tom |
Dec 9 2019, 08:46 PM
Post
#37
|
Advanced Member Group: Members Posts: 2,139 Joined: 21-August 05 From: Port Orchard, WA 98367 Member No.: 4,626 Region Association: None |
In your original post you said you had no power to either the coil or fuel pump. If fuse #9 under the dash is not good and passing power to pin #8 of the 14 pin connector at the relay board, neither the coil will have power nor the fuel pump. Pin #8 feeds power to the POWER relay on the relay board witch in turns passes power to the fuel pump relay. Check that there is power at Pin #8 with the key switch on.
Tom EDIT: I was looking at my prints and I was wrong. The power to pin 8 of the 14 pin connector does come from fuse #9, but it is from the un-fused side ( or hot side). One would still need to confirm that when the key is turned on, there is power at pin #8 of the 14 pin connector for the relay board and at the power relay thru the relay board traces and on to the fuel pump relay. Tom |
pastormacman |
Dec 14 2019, 12:11 PM
Post
#38
|
Newbie Group: Members Posts: 28 Joined: 6-July 05 From: Bakersfield, CA Member No.: 4,382 |
OK. I retested all the relays I have on the headlight motors and I have four working relays. I've tried all four relays on both the power and fuel pump relay posts with no joy. I was not even getting power to pin #1 on the ECU connector.
I also temporarily hard wired pin 30 to pin 87 (on the power relay post on the relay board) and I did get continuity to pin#1 on the ECU connector. So the relay board is good.So I checked fuse #9 There is no power on either side of fuse #9 under the dash. Key on or off makes no difference. As I understand it, power from fuse #9 is what triggers the power relay to pass power from pin 30 to pin 87 So my relays are working, but the signal for them to pass power on is not being triggered. In fact, I connected everything up, but removed the power relay. I connected the battery, turned on the key, and hardwired pin 30 to pin 87 on the power relay post, and the fuel pump kicked on. So now I know it all works except power to fuse #9 under the dash. So what could be stopping power to fuse #9 under the dash? |
pastormacman |
Dec 14 2019, 12:30 PM
Post
#39
|
Newbie Group: Members Posts: 28 Joined: 6-July 05 From: Bakersfield, CA Member No.: 4,382 |
Make sure the fuel hose isn't kinked, it's easy to do When we first put the fuel tank back in the car the hoses were kinked and we didn't know it. We set the fuel tank in place and poured in about a gallon of gas, but we didn't see any gas flowing into the fuel filter back by the engine. So using a small wooden dowel, we were able to manipulate the hoses under the tank. We slid and pushed the fuel lines around until one of them felt like it went free and we heard a girggling sound. I went to the back and saw fuel in the filter. We haven't touched the lines since and I'm assuming it still flows. |
Spoke |
Dec 14 2019, 12:58 PM
Post
#40
|
Jerry Group: Members Posts: 7,106 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
There is no power on either side of fuse #9 under the dash. Key on or off makes no difference. As I understand it, power from fuse #9 is what triggers the power relay to pass power from pin 30 to pin 87 Power to fuse 9 comes from the ignition switch. From the schematics, it looks like 12V to the ignition coil and relays on the relay board do not use fuse 9. QUOTE So what could be stopping power to fuse #9 under the dash? Fuse 9, the ignition coil, and the relays on the relay board are powered through the ignition switch. The only items between Fuse 9, the ignition coil, and relays on the relay board are the ignition switch and the wires to the ignition switch from the battery. If the wires are ok and you measure 12V at the ignition switch, it would seem your ignition switch has taken a dump. Do other items such as brake lights, turnsignals work with the ignition key on? |
Lo-Fi Version | Time is now: 4th January 2025 - 06:23 PM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |