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> A couple questions about fuel pumps
Craigers17
post Sep 18 2023, 08:54 AM
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I replaced my fuel filter yesterday trying to get to the bottom of a backfiring issue, which hasn't been an issue since I replaced the carbs about 8 or 9 months ago. In addition, about a month ago, the points actually went bad, and the car started running poorly. I recently replaced the points, and it got the car running well at idle. However, the backfiring issue continued, so yesterday I decided to replace the fuel filter(and I bathed in quite a bit of fuel in the process).

After replacing the filter and remounting the facet fuel pump, I noticed that the fuel pump is very noisy all the time. It used to be easy to hear right at start up, but then faded out under the noise of the engine. Now I can clearly hear it all the time. As a side note, about 3 weeks ago, upon start up I noticed that I could barely hear it.....which was unusual(In other words, the sounds of the pump seem to be going in and out). There is no rubber between the pump and the firewall which is where it is located, so I know that could be an issue. My question is are these varying noises with the fuel pump a sign that it could be failing? Also, I assume that if it was failing, this could cause backfiring issues?

I made sure the carbs were synced again today, and the measure about 6 with the AFM at idle and as I give it throttle, the measurements between sides remains consistent.

My only other question is are points made specifically to match distributors and engine size or distributor only? The points I installed were for 009 and 034 distys, but it says on the package that they are for 12-1600cc engines. They SEEM to be working fine, and I gapped them at .016. According to my digital timing gun, the dwell is spot on at 47 degrees. I know that's a lot of questions, but any help would be appreciated.
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MikeK
post Sep 18 2023, 09:08 AM
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If your dwell is at 47 and your timing is correct, you're probably just fine.

Backfiring is a lean condition. First two things I'd do is check the pressure of your questionable pump and blow out your idle jets. Are all four cylinders firing at idle? You might want to start by pulling plug wires.
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Superhawk996
post Sep 18 2023, 09:09 AM
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Facet pumps are noisy by nature.

When I had one the noise seemed to vary a bit based on ambient temperature and how much fuel I had in the tank which would vary the head pressure the pump inlet sees.

Have you checked your fuel lines under the tank. A kinked line to the pump would change how it sounds and can also lead to some fuel starvation issues when you need higher flow rates.

Like yours, my facet used to be louder at key on until it got a full slug if fuel flowing through it. Could yours have gotten loud all the time because it isn’t getting a good supply of fuel from the tank (kinked line or clogged strainer in tank)?
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Craigers17
post Sep 18 2023, 09:20 AM
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QUOTE(MikeK @ Sep 18 2023, 09:08 AM) *

If your dwell is at 47 and your timing is correct, you're probably just fine.

Backfiring is a lean condition. First two things I'd do is check the pressure of your questionable pump and blow out your idle jets. Are all four cylinders firing at idle? You might want to start by pulling plug wires.


I just blew out the jets before I installed the new filter. All cylinders firing at idle and the car has plenty of power. I probably need to reinstall my pressure gauge, and I could check the pressure. Thanks.
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Craigers17
post Sep 18 2023, 09:31 AM
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QUOTE(Superhawk996 @ Sep 18 2023, 09:09 AM) *

Facet pumps are noisy by nature.

When I had one the noise seemed to vary a bit based on ambient temperature and how much fuel I had in the tank which would vary the head pressure the pump inlet sees.

Have you checked your fuel lines under the tank. A kinked line to the pump would change how it sounds and can also lead to some fuel starvation issues when you need higher flow rates.

Like yours, my facet used to be louder at key on until it got a full slug if fuel flowing through it. Could yours have gotten loud all the time because it isn’t getting a good supply of fuel from the tank (kinked line or clogged strainer in tank)?


I ended up "accidentally" losing about 5 gallons of gas due to piss poor planning with taking off the filter and replacing the fuel line to the engine compartment. Based on that and how fast the fuel was coming out (mostly all on me and the floor)just due to gravity, I don't think there is any clogging going on. Seriously though, I doubt there is anything going on under the tank. The only thing that really changed was the filter.

Either way, I am seriously contemplating that this might be the time to change over to SS Tangerine lines and new Tangerine pump/filter combo. In that case, I'll be pulling the tank and changing out the sock/strainer and rubber lines under the tank, so that will rule all of that out. Thanks.
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Superhawk996
post Sep 18 2023, 12:47 PM
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QUOTE(Craigers17 @ Sep 18 2023, 11:31 AM) *


I ended up "accidentally" losing about 5 gallons of gas due to piss poor planning with taking off the filter and replacing the fuel line to the engine compartment.

We’ll, that’s one way to prove a point (IMG:style_emoticons/default/dry.gif)
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rhodyguy
post Sep 20 2023, 08:35 AM
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Next time, get a long piece of fuel line first, use your facet pump to drain the tank. Not wasting money, and taking a gas shower, will pay for the seldom used extra piece of fl.
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second wind
post Sep 20 2023, 06:28 PM
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I learned a lesson the hard way changing my fuel filter for the first time in my '73 2.0.
Fuel filter in the stock position and I had put a piece of carpet under the car for cushioning for my back. Well, as you said the gas poured out profusely and drenched the carpet I was lying on. I thought what the hell I use gas all the time to clean my hands and parts and such....no big deal that my back is soaking wet with gasoline. Well after cleaning up with a water hose and then a shower I figured I was good....NOT!! My entire back turned black and didn't feel so good as well. Learned my lesson....never again!
gg
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type2man
post Sep 20 2023, 06:37 PM
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If you had the issue since you installed the carbs, pehaps the jetting is wrong or you could have pinched the intake to head gasket if its the paper one causing a leak. What carbs and jets are in it?
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Craigers17
post Sep 20 2023, 06:59 PM
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QUOTE(rhodyguy @ Sep 20 2023, 08:35 AM) *

Next time, get a long piece of fuel line first, use your facet pump to drain the tank. Not wasting money, and taking a gas shower, will pay for the seldom used extra piece of fl.


I probably over-embellished my experience as I thought there was some humor in it. I did however get gas all over me. I was able to ultimately funnel most of the gas into an old gas can, by pretty much disconnecting the line from the carb t and using the extra length to get to the can.....lesson learned.
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Craigers17
post Sep 20 2023, 07:06 PM
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QUOTE(second wind @ Sep 20 2023, 06:28 PM) *

I learned a lesson the hard way changing my fuel filter for the first time in my '73 2.0.
Fuel filter in the stock position and I had put a piece of carpet under the car for cushioning for my back. Well, as you said the gas poured out profusely and drenched the carpet I was lying on. I thought what the hell I use gas all the time to clean my hands and parts and such....no big deal that my back is soaking wet with gasoline. Well after cleaning up with a water hose and then a shower I figured I was good....NOT!! My entire back turned black and didn't feel so good as well. Learned my lesson....never again!
gg


I didn't get any type of skin reaction, but this was pretty much my exact experience. I guess there are probably tricks to doing this, but without a lift, there is minimal room to work and my headers restrict some arm movement to get to that area. Moreover, I didn't want to pinch the line, because it's the original plastic line that I would have to pinch to stop the flow.

Bottom line: Since the tank is near empty, I'm going to remove it, install SS lines, and move the pump and filter up to the frunk. IMHO, the original location sucks, and I'm not gonna put it below the tank. I rarely use the front trunk for anything, and it seems to be the best place to put it. As a side note, I have a 1990 F-150 and I changed the fuel filter in that the week before in about 5 minutes, no mess, no floor jack, no fuel loss, no drama.
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Craigers17
post Sep 20 2023, 07:12 PM
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QUOTE(type2man @ Sep 20 2023, 06:37 PM) *

If you had the issue since you installed the carbs, pehaps the jetting is wrong or you could have pinched the intake to head gasket if its the paper one causing a leak. What carbs and jets are in it?


If you reread my original post, it's exactly the opposite of that. After I changed the carbs I had no backfire issue until the points went bad several months later. Nothing has really changed to the carbs, but as stated, the fuel pump seems suspect. I'm gonna put the fuel pressure gauge back on it and run it for a while to see if it stays around 3. I'm running dual EMPI 40's, with 28's, either 50 or 52 idles, 130 main jets, and 200 main airs.
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Craigers17
post Sep 21 2023, 02:51 PM
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So I re-installed the fuel pressure gauge, and it's definitely fluctuating. When I first put it back on we were right at 3psi, but then after a few minutes it went down to 2 and then even the high ones. Not sure if that confirms that the pump is failing, but I haven't seen that kind of fluctuation in the past.

My facet pump is currently drawing power from the positive side of the coil. Is that normal? And if I relocate it to the front, where is the best place to bring power from?
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ClayPerrine
post Sep 22 2023, 04:37 AM
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Pulling power from the coil is a bad idea. The pump can't get enough power, and it pulls power from the coil, so the spark gets weaker. Lots of "mechanics" would do this because it was easy, not right.

I would suggest that you wire up the original pump power circuit. SirAndy put a thread on here that tells how to get the fuel pump circuit to work with carbs .
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Craigers17
post Sep 22 2023, 05:11 AM
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QUOTE(ClayPerrine @ Sep 22 2023, 04:37 AM) *

Pulling power from the coil is a bad idea. The pump can't get enough power, and it pulls power from the coil, so the spark gets weaker. Lots of "mechanics" would do this because it was easy, not right.

I would suggest that you wire up the original pump power circuit. SirAndy put a thread on here that tells how to get the fuel pump circuit to work with carbs .



Thanks Clay. I found the thread you are referring to.
Here it is for anyone who might read this thread and need it:

http://www.914world.com/specs/SirAndyCarbFuelPumpRelay.php
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