 Fuel Pump Diagnostics |
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| solex |
  Mar 21 2010, 12:40 PM
Post
#1
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Senior Member  Group: Members Posts: 789 Joined: 12-January 05 From: Long Island, NY Member No.: 3,439 Region Association: North East States  |
Hi All,
Need a little help to diagnose a fuel pump problem in a 75, I do not hear the pump when I turn the key to the run position. The car was running, I had a few occasions where it would not start, let it sit for a few days and it was start right up. The grounds: under the relay board, battery and transmission have all been cleaned. All fuses are good. The relay is working as I can hear it click into position. When the key is in the run position relay terminals 30 and 85 shows 12 volts. Terminal 86 show 0.03 volts and terminal 87 show zero volts. There is no voltage at either of the fuel pump terminals. The readings at the relay is counter to to what Haynes states (86 should read 12 and 85 should be ground). I not sure where to check next, really do not want to pull the tank. Any assistance would be appreciated. Thanks, Dan |
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Posts in this topic
solex Fuel Pump Diagnostics Mar 21 2010, 12:40 PM
Cap'n Krusty
Hi All,
Need a little help to diagnose a fuel pum... Mar 21 2010, 01:29 PM solex Cap'n I know this I checked the connections at... Mar 21 2010, 02:06 PM kwales One of the two wires connected to the pump is the ... Mar 21 2010, 03:50 PM
solex
One of the two wires connected to the pump is the... Mar 21 2010, 03:58 PM black73 I have had problems with bad connections at the fu... Mar 21 2010, 05:44 PM underthetire I've had problems with the relay not fitting i... Mar 21 2010, 08:18 PM kwales Most VOM's have a continuity checker that beep... Mar 21 2010, 08:29 PM kg6dxn 30 is power from tha battery
85 is pump on power f... Mar 21 2010, 11:28 PM 914_teener
30 is power from tha battery
85 is pump on power ... Mar 21 2010, 11:57 PM solex Gentlemen,
Thank you for the suggestions, I will g... Mar 22 2010, 06:39 AM mikea100 I’ve had problem with the relay top plate stuck ... Mar 22 2010, 08:52 AM ericread I had a similar problem a few months ago. Rather ... Mar 22 2010, 10:42 AM 914_teener
I had a similar problem a few months ago. Rather... Mar 22 2010, 02:45 PM solex Guys thank you for the pbanders post. I diagnosed... Apr 4 2010, 03:38 PM solex BTW, what is the best way to clean the tar off of ... Apr 4 2010, 05:19 PM 914_teener
BTW, what is the best way to clean the tar off of... Apr 4 2010, 11:29 PM 76-914
BTW, what is the best way to clean the tar off of... Apr 5 2010, 08:53 AM solex Hi, I finally got around to getting another board ... Apr 24 2010, 03:24 PM 76-914 Isn't there always some voltage to the relay b... Apr 24 2010, 09:54 PM swl Dan this may be be an 'of course I know that... Apr 25 2010, 06:24 AM swl oh - and another 'I know that' comment. I... Apr 25 2010, 06:33 AM solex Steve, Mike,
Shorting 87 to 30 on the Fuel Pump R... Apr 25 2010, 12:03 PM swl so next step - other than working on the old board... Apr 25 2010, 07:32 PM toadman Check your fuel pump. I had a similar problem wit... Apr 26 2010, 08:19 PM realred914 I have used a heat gun to remove the tar. however... Apr 27 2010, 09:00 AM solex I jumped pin III with the plug in the board and st... Apr 27 2010, 08:35 PM swl
I jumped pin III with the plug in the board and s... Apr 28 2010, 07:53 PM solex Steve, Yes that is what I did but the pump did not... Apr 28 2010, 08:40 PM swl Sounds like you are getting really close.
This ... Apr 29 2010, 07:13 PM solex
Sounds like you are getting really close.
This... May 1 2010, 08:38 PM swl I'm all for being methodical in trouble shooti... May 2 2010, 09:10 AM solex Back on this again. Took the car out a few times ... May 15 2010, 03:24 PM swl I think the 2 port pump (front mounted) is still a... May 15 2010, 04:22 PM solex
I think the 2 port pump (front mounted) is still ... May 15 2010, 04:27 PM black73 That's the way mine was acting before I replac... May 15 2010, 05:31 PM avidfanjpl It is not at all unusual to have 3 problems all at... May 15 2010, 05:43 PM solex Thanks for the suggestions:
(1) I just replace th... May 15 2010, 09:59 PM solex Pricing varies but does this look good;
http://ww... May 15 2010, 10:06 PM swl Dan you may well be looking at a new pump. I... May 16 2010, 05:10 AM ClayPerrine I have a suggestion.....
Hook a wire to the posi... May 16 2010, 07:58 AM swl Clay that's brilliant! You must be a race... May 16 2010, 08:04 AM solex Quick update. I connected a DVM to the pump and t... May 16 2010, 08:42 PM ClayPerrine Something is getting hot and causing the voltage t... May 16 2010, 09:52 PM solex
Something is getting hot and causing the voltage ... May 17 2010, 08:16 AM swl That's right dan. 1.5 seconds unless you grou... May 17 2010, 10:22 AM solex Steve,
I will check again when I get home tonight,... May 17 2010, 10:31 AM ClayPerrine No... it would not be in the fuel pump side.
Th... May 17 2010, 11:15 AM solex Clay,
Thank you for spending the time to explain, ... May 19 2010, 09:22 PM ClayPerrine
Clay,
Thank you for spending the time to explain,... May 20 2010, 06:35 AM swl ah yes the aux air regulator! It runs off the... May 20 2010, 05:44 AM plas76targa Solex, this is a great thread. I've experienc... May 20 2010, 05:56 AM solex Today I decided to check the fuses based on Matt r... May 23 2010, 08:19 PM swl That looks pretty conclusive Dan. And also where ... May 25 2010, 03:14 PM solex Got a new pump from Pelican yesterday and installe... May 27 2010, 06:58 PM solex Gentlemen just wanted to report back on the status... Jun 13 2010, 07:44 PM  |
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