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Fuel pump runs but no flow. by Vogtoauto
Started on: 04-12-2015 02:10 PM
Replies: 31 (619 views)
Last post by: Vogtoauto on 04-22-2015 05:41 PM
Vogtoauto
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Report this Post04-12-2015 02:10 PM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
New here and in dire need of help. Working on a '86 SE (haven't bought it yet). Installed new fuel pump, won't pump. Can hear it running. Pulled it back out and got another. Tested it before installing. Pumped fuel out of a coffee can. Nice stream. Installed tank in car. No flow. Can hear it running. Pulled it and bench tested it again. Won't pump now. Got a third one. Cost three times as much, but you get what you pay for, right? Tested it in tank before putting tank in. Worked great. Put tank in this morning. No flow again. pulled hose off before filter, no flow. Pulled hose off under car at tank, no flow. I can draw fuel up the line with a Mityvac hand pump, but the pump won't move it even then. By the way, there's 5 gallons in tank. That should be about half full. I measured the level in tank and depth of pump. It's four inches under fuel. That's about the length of the entire pump. Battery is up and tested 12.33 volts at three-wire connection.
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Gall757
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Report this Post04-12-2015 03:27 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
Welcome to the Forum!

Maybe your pump wiring got reversed.....
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Csjag
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Report this Post04-12-2015 04:03 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:

Welcome to the Forum!

Maybe your pump wiring got reversed.....


Yes, I second that, it happened to me.
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Vogtoauto
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Report this Post04-12-2015 05:01 PM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
When I bench tested it before installation, I put battery voltage to the brown,black stripe wire and grounded the black wire. I just went out and checked the connector that plugs into here, the wire colors match up. I checked for voltage, got battery voltage at brown/black stripe wire and none at black. Checked for continuity between black wire and ground, got good continuity. Did this with the key so I made sure to test the exact circuit that the pump would see. Of course, the battery voltage at the brown/black stripe wire shut off in a couple seconds when the relay kicked back out.
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vette7584
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Report this Post04-14-2015 10:36 PM Click Here to See the Profile for vette7584Click Here to Email vette7584Send a Private Message to vette7584Edit/Delete MessageReply w/QuoteDirect Link to This Post
is it aftermarket pump? i also agree with wiring being backward. i just put a high volume pump into my 1988 before i started my 3800sc swap, i paid attention to the connector on pump, it is marked + and - , but they are opposite from stock..
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Csjag
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Report this Post04-14-2015 10:41 PM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by vette7584:

is it aftermarket pump? i also agree with wiring being backward. i just put a high volume pump into my 1988 before i started my 3800sc swap, i paid attention to the connector on pump, it is marked + and - , but they are opposite from stock..


I agree, my bosch replacement was opposite from stock too.
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Vogtoauto
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Report this Post04-15-2015 05:52 PM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Ok, but when I tested it out of the car, I went through the harness. I already had the pump mounted and in the tank. Put power to the brown wire and grounded the black. It pumped fine then. All we did was put the tank in the car, we never disturbed the pump or wiring. I confirmed that the brown wire coming from the vehicle to the pump harness' brown wire is battery voltage and the car's harness' black wire is ground. The black wire from the tank is grounded to the tank, also. If I was to reverse the wires in the harness, the brown would be going to a ground and be shorted out.
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Patrick
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Report this Post04-15-2015 06:06 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
Have you tried powering the pump through the appropriate connector on the ALDL panel? Doing so bypasses the relay, thus eliminating some variables.

[EDIT] Of course, after re-reading your opening post, I realize my suggestion is rather dumb considering that the pump is running... just not pumping.

[This message has been edited by Patrick (edited 04-15-2015).]

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tebailey
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Report this Post04-15-2015 06:37 PM Click Here to See the Profile for tebaileyClick Here to Email tebaileySend a Private Message to tebaileyEdit/Delete MessageReply w/QuoteDirect Link to This Post
Did you install the filter sock on the end of the pump?
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Vogtoauto
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Report this Post04-15-2015 07:04 PM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Yes, that's how I have been trying it when the tank is in the car, by powering it through the ALDL when I try something new. The first two pumps came with new socks, the third one did not but I purchased one separately.
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Patrick
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Report this Post04-15-2015 08:02 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Vogtoauto:

Battery is up and tested 12.33 volts at three-wire connection.


I've been told that's not enough voltage for a good battery. I don't know how much difference a bit more voltage might make with a fuel pump, but...

 
quote
Originally posted by theogre:

12.29 is low battery...
See my Cave, Battery

A 12V lead acid battery is fully charged at 12.6-13V. The general formula for a Lead Acid battery is 2.1 volts per cell. A 12V battery has 6 cells. A cell is fully charged at 2.1-2.2 volts.

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Vogtoauto
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Report this Post04-15-2015 09:07 PM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just went out again. Had charger on battery on low. I like to charge a battery on low for a longer time rather than boost quickly. 13.64 volts; no change. I can easily hear it running every time, just no fuel flowing.
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Report this Post04-16-2015 08:33 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Your situation appears to be a paradox.
If you have the time and the resources, Put your tank with new pump-sender into a willing subjects Fiero and put his "PROVEN" tank with pump-sender into your Fiero. This will provide you with 3 possible results.

1/ One pump will pump.
2/ Both pumps will pump.
3/ Neither pump will pump.

I can hardly wait to hear the results!!

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Patrick
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Report this Post04-16-2015 10:38 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Spoon:

If you have the time and the resources, Put your tank with new pump-sender into a willing subjects Fiero and put his "PROVEN" tank with pump-sender into your Fiero.


Damn, that's a lot of work.
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Report this Post04-16-2015 10:47 PM Click Here to See the Profile for f85gtronSend a Private Message to f85gtronEdit/Delete MessageReply w/QuoteDirect Link to This Post
Drop the tank (you should be good at our by now ), Then apply voltage from external source to connector and see if pumps out through fuel line. I bet you got a blockage, or pinched line along the top of the tank.
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Report this Post04-16-2015 10:52 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by f85gtron:

Drop the tank (you should be good at our by now ), Then apply voltage from external source to connector and see if pumps out through fuel line. I bet you got a blockage, or pinched line along the top of the tank.


I recall the lines across the top of the tank were steel. I could be wrong. That's why I didn't mention it.

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Patrick
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Report this Post04-16-2015 11:17 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Spoon:

I recall the lines across the top of the tank were steel.


If the OP has "pinched" the steel lines, we'll have to take his toolbox away.

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f85gtron
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Report this Post04-17-2015 05:48 AM Click Here to See the Profile for f85gtronSend a Private Message to f85gtronEdit/Delete MessageReply w/QuoteDirect Link to This Post
Could be swelled up lines. Maybe the tank got dropped at some point and it was "enthusiastically unstuck" from it's home and a creased line was born? Don't ask me why I could imagine such a thing.......
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Report this Post04-17-2015 07:18 AM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
Is it possible that the rubber fuel lines are connected wrong and causing the pump to pump the gas back into the tank thru the return line?
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Gall757
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Report this Post04-17-2015 09:34 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Csjag:

Is it possible that the rubber fuel lines are connected wrong and causing the pump to pump the gas back into the tank thru the return line?


It would be helpful to know if any other work has been done on the car.....perhaps in the area of the fuel rail.
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Report this Post04-17-2015 11:15 AM Click Here to See the Profile for darbysanClick Here to Email darbysanSend a Private Message to darbysanEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just another thought, which I have seen a lot over on the Thridgen site. The small piece of rubber hose that attaches the pump to the sender splits. The pump runs, but it's basically just spraying fuel inside the tank. It happens quite often, and was a problem for a while with pump installs because the small piece of fuel line that was supplied with the kit was so old it would split soon after install. For this reason, I always buy a small piece of fresh "submersible" fuel line at NAPA for pump installs, just to be on the safe side. Spec on the hose is SAE 30R10, 3/8". IF you use a standard FI hose there, it will disintegrate over time, so only use the submersible spec hose.

------------------
'87 GT in process!

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Report this Post04-17-2015 03:54 PM Click Here to See the Profile for f85gtronSend a Private Message to f85gtronEdit/Delete MessageReply w/QuoteDirect Link to This Post
This guy's head has got to be spinning from all these suggestions. I can't wait to see what the outcome is.
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Vogtoauto
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Report this Post04-17-2015 05:33 PM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Wow! I really appreciate all the responses and suggestions, 'cause i'm at my wit's end. I'm gonna respond to these one by one.
First, f85gtron, I had applied voltage to the pump through the harness after I had put the pump in the tank, but before installing the tank in the car. It pumped fuel through the steel line and rubber hose that I stuck back in the tank fill hole. I ran it probably 10-15 seconds pumping a full stream, then installed tank under car without disturbing pump, lines or hoses.
Csjag, The feed and return lines are different sizes, I actually replaced them both the first time around. The third one I'm not sure what it is, it had a "squeeze clamp" on it and looked OK. When the pump wouldn't pump in the car, I pulled back off the hoses under the car and let them hang to try again with the hose pointing to the ground to eliminate the possibility of any blockage, although I can blow back through with my mouth from the filter inlet back with the hose unhooked.
Gall757, I don't know of any other work done. The car was brought to me in non-running condition after sitting, it appears, for quite a few years. The current owner, who never had it running, is letting me see if I want to buy it. It's SUPPOSED to have a good engine. (We all know how that goes). I was gonna get it running as cheaply as possible, and go from there. I figured if the engine didn't knock and the tranny moved the car, I'd buy it and make improvements from there. It DID start and run a second or two when I dribbled some gas down the TBI, so I was hopeful. Then, this fiasco with the pump has got me pissed off. I'm tempted to tell him to take it back, but it's got me so pissed I don't want to give up now.
darbysan, the first time the pump was replaced, I threw away the hose that was in there 'cause it looked poor. Actually, the first two cheap pumps came with 5/16 hose to fit on the 3/8 nipples. I cut a new piece for those two. (Always keep a few feet on hand). The third one came with a very thick hose and the plastic notched-type clamps you squeeze with a pliers, so I used that set-up.
And yes, I am getting VERY good at removing this tank! Gotta stop now, the two fingers I type with are getting sore.
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Vogtoauto
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Report this Post04-17-2015 09:53 PM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
People! Update time! Took the boy out to the garage and dropped the tank again. Csjag, Gall757, and vette7584, now pay attention. You all mentioned the wires being reversed. Now, remember, the pump ran and PUMPED FUEL when I tested it before installing the tank. I saw it flowing with my own eyes. It came out the pressure hose and I directed it back into the filler tube hole. Now, when we pulled it out tonight, I tried testing it again exactly the same way, and it ran but did NOT pump fuel. I looked for polarity markings, had my boy with the 42 year younger eyes look for markings, then I got a magnifying glass and could not find any. I reversed the wires anyhow, tested it and now it DOES move fuel! Did it somehow reverse polarity moving it from the bench to the car? By the way, when I took out the original one, it just had the wires on the pins individually. The two cheap pumps, I hooked up this way, also. This last pump came with a plastic connector for the wires to plug into and then a separate keeper to lock them in, then it snapped onto the pump. It's late, so we quit for the night, but I'm hopeful. We'll put the tank in the car after we get back from the swap meet at Hawkeye Downs in Cedar Rapids, tomorrow. Pleasant dreams, all!
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Gall757
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Report this Post04-18-2015 11:31 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Vogtoauto:
Csjag, Gall757, and vette7584, now pay attention. You all mentioned the wires being reversed.


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Report this Post04-18-2015 04:30 PM Click Here to See the Profile for SpoonSend a Private Message to SpoonEdit/Delete MessageReply w/QuoteDirect Link to This Post
"( Did it somehow reverse polarity moving it from the bench to the car?)"

Sounds like a $10. multimeter from Harbor Freight could of saved you a lot of grief.

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

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Report this Post04-18-2015 05:06 PM Click Here to See the Profile for f85gtronSend a Private Message to f85gtronEdit/Delete MessageReply w/QuoteDirect Link to This Post
Good job. Now your an expert!
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Vogtoauto
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Report this Post04-18-2015 10:22 PM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm curious. What should I have been testing that I missed?
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Gall757
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Report this Post04-19-2015 10:13 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Vogtoauto:

I'm curious. What should I have been testing that I missed?


+1. Did you attach live wires to the pump on your bench test? Perhaps the order of attachment determines the rotor direction.
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Report this Post04-19-2015 11:14 AM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Yes, put power to brown/black stripe wire and grounded black wire. That's the same as the feed harness from car, same colors, also. Fuel pumped from the line on bench. Didn't change a thing, simply took tank from bench and installed in car. Even used same battery for bench test. Believe me, if it didn't pump fuel on the bench, I wouldn't have installed the tank in the car again. This is why I'm so confused. If the leads were reversed, as they must have been, why did it pump fuel?
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Report this Post04-19-2015 11:17 AM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post

Vogtoauto

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Member since Apr 2015
Oh, I forgot to add, the test wires I used to reach from car harness to pump harness during bench test, I added a switch in the middle so I could hook up wires, then flip switch on away from battery and tank. This is after I put power to ALDL to continuously power pump relay.
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Report this Post04-22-2015 05:41 PM Click Here to See the Profile for VogtoautoClick Here to Email VogtoautoSend a Private Message to VogtoautoEdit/Delete MessageReply w/QuoteDirect Link to This Post
Forgot to mention it's running, now. Thanks to everyone for your help. I think it sounds pretty good, considering the stickers are from 2008, I think. They're kinda faded; when were the stickers red? Definitely like this forum; lots of great ideas. Need to work on brakes, put console back together and saw a post about the heater fan resistor starting fires. Very good knowledge to have!
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