No fuel pump noise, Car not starting |
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No fuel pump noise, Car not starting |
brooks944 |
Dec 24 2014, 12:29 PM
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#1
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Member Group: Members Posts: 241 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States |
The annoying fuel pump noise isn't coming on when the key is turned on. I tried a couple of times to see if it would start, no luck. The car has a new fuel pump relay. What do I need to check first?
BTW, the FP noise is really nice when the car is running.... Thanks, Rick |
Mike Bellis |
Dec 24 2014, 12:43 PM
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#2
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Resident Electrician Group: Members Posts: 8,345 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None |
You need to check for power at the fuse, relay and at the fuel pump.
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Steve Snyder |
Dec 24 2014, 01:13 PM
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#3
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Member Group: Members Posts: 241 Joined: 10-June 08 From: Graham, NC Member No.: 9,158 Region Association: South East States |
The car has a new fuel pump relay.. Assuming that you replaced the relay after the pump stopped working, I agree with Mike, although I would check the actual fuse first, then start with a meter at the pump itself (power reading while jumping across the pump terminals would indicate a failed pump, no voltage read across terminals but read from either pump terminal to ground point would imply pump grounding issue, etc.). |
poorsche914 |
Dec 24 2014, 01:39 PM
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#4
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T4 Supercharged Group: Members Posts: 3,091 Joined: 28-May 09 From: Smoky Mountains Member No.: 10,419 Region Association: South East States |
Rick,
Hot wire the fuel pump to be sure it is working. Then go from there. steve (IMG:style_emoticons/default/driving.gif) |
brooks944 |
Dec 24 2014, 01:40 PM
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#5
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Member Group: Members Posts: 241 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States |
Tanks guys. Where is the fuse? The relay was replaced before it stopped working. My car is a 75 1.8 with original FI.
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dlee6204 |
Dec 24 2014, 03:14 PM
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#6
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Howdy Group: Members Posts: 2,162 Joined: 30-April 06 From: Burnsville, NC Member No.: 5,956 |
Tanks guys. Where is the fuse? The relay was replaced before it stopped working. My car is a 75 1.8 with original FI. And that is very helpful information. Original fuel injection for a 1.8l is L-Jet and you Should NOT hear the fuel pump with the key turned on. For L-Jet the fuel pump only runs when cranking or running. What relay did you replace? The dual relay by the battery? |
brooks944 |
Dec 24 2014, 03:38 PM
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#7
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Member Group: Members Posts: 241 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States |
Thanks, but the pump has run whenever the key has been turned since I got it. Is something wired wrong? Haven't had the car that long so not sure what it's supposed to do.
Is there a separate fuse for the pump or only the relay? |
colingreene |
Dec 24 2014, 03:40 PM
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#8
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Senior Member Group: Members Posts: 729 Joined: 17-October 13 From: Southern California Member No.: 16,526 Region Association: Southern California |
before i got carried away id check for voltage at the pump key on and cranking.
Then work my way back rather than hot wire stuff. That could cause damage... |
brooks944 |
Dec 24 2014, 03:40 PM
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#9
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Member Group: Members Posts: 241 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States |
Yes it was the relay by the battery, sorry didn't answer the question!
Rick |
dlee6204 |
Dec 24 2014, 04:14 PM
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#10
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Howdy Group: Members Posts: 2,162 Joined: 30-April 06 From: Burnsville, NC Member No.: 5,956 |
So did the fuel pump run all the time that the key was turned on? If so it sounds like someone hot wired the fuel pump. This is common for carburator cars but for FI it shows there is an issue with the wiring and/or FI System.
A lot of people hot wire the fuel pump to run directly off the coil. Do you notice any homemade wiring in the engine bay? The best way though is to trace the wires from the fuel pump and see where they go and compare it to a factory wiring diagram since it sounds like there is some "custom" wiring. If you could care less about the custom repairs and simply want it to run then you should see if you have 12V+ at the terminals on the fuel pump. That will at least tell you if you have a bad fuel pump. |
dlee6204 |
Dec 24 2014, 04:16 PM
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#11
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Howdy Group: Members Posts: 2,162 Joined: 30-April 06 From: Burnsville, NC Member No.: 5,956 |
Also if you want to do some reading on the correct way the fuel pump gets its power, then this great thread talks in detail about that dual relay you replaced by the battery.
http://www.thesamba.com/vw/forum/viewtopic.php?t=334340 |
brooks944 |
Dec 24 2014, 05:48 PM
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#12
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Member Group: Members Posts: 241 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States |
Thanks Doug. I will check that link. Noticed you have a Mars Hill address. I am a '77 graduate from there, but it was a college and not a university in the old days.
Merry Christmas, Rick |
Mike Bellis |
Dec 24 2014, 05:57 PM
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#13
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Resident Electrician Group: Members Posts: 8,345 Joined: 22-June 09 From: Midlothian TX Member No.: 10,496 Region Association: None |
(IMG:style_emoticons/default/thisthreadisworthlesswithoutpics.gif)
(IMG:style_emoticons/default/biggrin.gif) Here is the factory relay board with fuel pump relay... |
brooks944 |
Dec 25 2014, 09:10 AM
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#14
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Member Group: Members Posts: 241 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States |
Steve, is there a separate fuse for the fuel pump? If so, where is it located?
Thanks, Rick |
dflesburg |
Dec 25 2014, 09:14 AM
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#15
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Senior Member Group: Members Posts: 1,720 Joined: 6-April 04 From: Warm and Cheerful Centerville Ohio Member No.: 1,896 Region Association: None |
if you wire it backwards it wont run.
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brooks944 |
Dec 25 2014, 09:33 AM
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#16
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Member Group: Members Posts: 241 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States |
I haven't had the pump disconnected so haven't messed with any wiring. Do you know if there is a separate fuse for the pump and where it's located?
Thanks, Rick |
dlee6204 |
Dec 25 2014, 09:40 AM
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#17
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Howdy Group: Members Posts: 2,162 Joined: 30-April 06 From: Burnsville, NC Member No.: 5,956 |
On the relay board in the engine bay there are two fuses. The rearward one should be a 25A and it is the fuse for the fuel pump.
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rhodyguy |
Dec 25 2014, 09:41 AM
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#18
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,093 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
what year is your car? has the fuel pump been moved from the stock location? i've never quite understood how the fuel pumps get powered when moved from the rear to the front and utilize the stock circuitry.
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brooks944 |
Dec 25 2014, 09:48 AM
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#19
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Member Group: Members Posts: 241 Joined: 5-September 10 From: Kingston, TN Member No.: 12,139 Region Association: South East States |
My car is a 75 with the 1.8L, so the fuel pump is already in the front trunk. Is there a way to check the fuses on the relay board? Really appreciate the help.
Rick |
dlee6204 |
Dec 25 2014, 09:57 AM
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#20
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Howdy Group: Members Posts: 2,162 Joined: 30-April 06 From: Burnsville, NC Member No.: 5,956 |
You should be able to visually look at the fuse and see if it's blown. I usually twist it back and forth a little bit in case it's making poor contact in its holder.
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