 Bad fuel pump, How do I test? |
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| wrpspddrvr |
 May 15 2005, 06:38 AM
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#1
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Member  Group: Members Posts: 333 Joined: 22-December 04 Member No.: 3,317 Region Association: None  |
Hi all. My feul pump stopped working. How do I go about checking if it's the pump itself or the rlays or something?
I'm dyin' here! Thanks! Cole (IMG:http://www.914world.com/bbs2/html/emoticons/monkeydance.gif) |
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| CptTripps |
May 15 2005, 06:49 AM
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#2
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:: Punch and Pie :: Group: Members Posts: 3,584 Joined: 26-December 04 From: Mentor, OH Member No.: 3,342 Region Association: Upper MidWest |
Take it out, plug it into a 12V power supply, and see if it pushes water or fuel. That's how I did it anyway... |
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| wrpspddrvr |
May 15 2005, 06:53 AM
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#3
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Member Group: Members Posts: 333 Joined: 22-December 04 Member No.: 3,317 Region Association: None |
How do I plug it into a 12v power supply? I have very little clue about electrical stuff. I can splice wires.....
IOW, where do I find a 12v supply, what wires do I put where, etc.... Thanks! Cole (IMG:http://www.914world.com/bbs2/html/emoticons/monkeydance.gif) |
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| CptTripps |
May 15 2005, 06:58 AM
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#4
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:: Punch and Pie :: Group: Members Posts: 3,584 Joined: 26-December 04 From: Mentor, OH Member No.: 3,342 Region Association: Upper MidWest |
Just make leads, and hook it up to a battery...There should only be two leads...put them to a battery. If it goes the wrong way, it's hooked up backwards.
That's really all the more complicated it is... |
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| wrpspddrvr |
May 15 2005, 07:19 AM
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#5
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Member Group: Members Posts: 333 Joined: 22-December 04 Member No.: 3,317 Region Association: None |
Awesome. Back in a bit.
THANKS!!! Cole (IMG:http://www.914world.com/bbs2/html/emoticons/monkeydance.gif) |
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| ClayPerrine |
May 15 2005, 07:24 AM
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#6
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Life's been good to me so far..... Group: Admin Posts: 15,465 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille 
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more simple that that. Disconnect the fuel pump. Hook a test light across the fuel pump connections. Turn the key on. The test light should come on for 2 seconds then go out (That is assuming it's a 1.7 or 2.0 with stock injection). If it doesn't, then there is a problem with the fuel pump wiring. If it does light up, replace the fuel pump.
AND DON'T USE WATER TO TEST A FUEL PUMP!!! Gasoline is used to cool the pump, and water willl cause the wiring to corrode more raplidly. Not to mention that you also can't get allthe water out. So it is now in your fuel system waiting to make your car run bad....... |
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| CptTripps |
May 15 2005, 07:34 AM
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#7
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:: Punch and Pie :: Group: Members Posts: 3,584 Joined: 26-December 04 From: Mentor, OH Member No.: 3,342 Region Association: Upper MidWest |
Yeah...on second thought...that's good advise. Sorry bout that...I answered the question pre-coffee. If my fuel pump is always running, where shoudl I look? When I turn the key, I can hear it constantly running...is that a bad thing? Or do I have a crossed wire somewhere... |
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| ClayPerrine |
May 15 2005, 07:40 AM
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#8
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Life's been good to me so far..... Group: Admin Posts: 15,465 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille
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What year and engine? |
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| wrpspddrvr |
May 15 2005, 07:59 AM
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#9
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Member Group: Members Posts: 333 Joined: 22-December 04 Member No.: 3,317 Region Association: None |
Fuel pump is fine. I wired it to my battery and it ran. Crap.
So I assume it's something in the electrical system TO the fuel pump. I can check wires for breaks, but how do I "jump the relay" like Britt said? Any other things to check and far as electrical stuff is concerned for the FP? Thanks!!!!!!!!! You guys have been a big help. Cole (IMG:http://www.914world.com/bbs2/html/emoticons/monkeydance.gif) |
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| ClayPerrine |
May 15 2005, 08:15 AM
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#10
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Life's been good to me so far..... Group: Admin Posts: 15,465 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille
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Just put a jumper wire from pin 30 to pin 87 on the relay board for the fuel pump relay. The pump should run.
If not, check the fuse on the relay board. Clean up the contacts with some sandpaper (or swipe the toolwench's emory board she uses to file her fingernails (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) ). Put in a new fuse and jumper the relay again. Attached is the diagram of the relay board. Number 75 is the fuel pump relay. Attached thumbnail(s) 
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| ClayPerrine |
May 15 2005, 08:17 AM
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#11
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Life's been good to me so far..... Group: Admin Posts: 15,465 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille
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Also remember that the white wire on the engine harness is also tied to the fuel pump circuit. A short to ground in that wire will blow the fuse on the relay board.
The fuse is the one closest to the rear on the relay board. |
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| wrpspddrvr |
May 15 2005, 09:38 AM
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#12
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Member Group: Members Posts: 333 Joined: 22-December 04 Member No.: 3,317 Region Association: None |
Okay, I'm going out to try that now. I tried using my other relays in place of the normal one, didn't work. Replaced the fuse. It was blown. I replaced the one towards the rear of the car, it was blue. Blew another fuse, but still nothing.
Gonna go try jumping it. Thanks! Cole (IMG:http://www.914world.com/bbs2/html/emoticons/monkeydance.gif) |
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| Cap'n Krusty |
May 15 2005, 09:55 AM
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#13
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
If the fuse keeps blowing, jumping the terminals ain't gonna make it well. It's ALREADY got power ..................Fix the short, likely at the AAR. The Cap'n
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| CptTripps |
May 15 2005, 03:36 PM
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#14
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:: Punch and Pie :: Group: Members Posts: 3,584 Joined: 26-December 04 From: Mentor, OH Member No.: 3,342 Region Association: Upper MidWest |
I have a 72 2.0 w/Webber 44IDF Carbs. Any thoughts? |
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| ClayPerrine |
May 15 2005, 06:44 PM
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#15
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Life's been good to me so far..... Group: Admin Posts: 15,465 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille
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If you have carbs, the person that installed them made the fuel pump run whenever the key is on. That is kinda normal for a carb conversion.
If you have stock D-Jet FI, the fuel pump will run for 2 seconds when the key is turned on and then when the engine is running. With the stock L-Jet (74-75 1.8 only), the fuel pump will run anytime the starter circuit is engaged, and whenever there is enough airflow over the airflow meter to open the flap. |
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| Dave_Darling |
May 15 2005, 08:33 PM
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#16
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914 Idiot Group: Members Posts: 14,986 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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What the Cap'n said. BTW, for anyone else who has D-jetronic fuel pump issues/questions--Brad Anders has a troubleshooting flowchart on his excellent D-jet website. http://members.rennlist.com/pbanders . --DD |
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