1991 Ford F-150 - Gas tank won't fill
03-31-2015, 12:28 PM
#11
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Thread Starter
I was able to remove the front and rear filler necks without removing the bad. They were held in place by two hose clamps. Once removed I was able to remove the filler necks by slowly wiggling them out until free.
I tried what a few people suggested on other posts. Tried drilling extra vent holes. The gas went in easier from a gas tank. But not from an actual gas pump at the store. Very disappointed. Not sure if I just need a new filler neck or if it's something else.
I tried what a few people suggested on other posts. Tried drilling extra vent holes. The gas went in easier from a gas tank. But not from an actual gas pump at the store. Very disappointed. Not sure if I just need a new filler neck or if it's something else.
04-01-2015, 11:45 PM
#12
Member
Thread Starter
Anyone have any info on this issue?
I've read over a lot of posts and checked out links on Google searches.
I've read people stating it could be a charcoal canister issue, canister vent solenoid, vent hoses, etc.
I'm assuming to check these out I need to remove the bed of the truck? I have no idea. I'm at a loss on this issue.
My last resort would be to take the truck to a Ford dealer.
I've read over a lot of posts and checked out links on Google searches.
I've read people stating it could be a charcoal canister issue, canister vent solenoid, vent hoses, etc.
I'm assuming to check these out I need to remove the bed of the truck? I have no idea. I'm at a loss on this issue.
My last resort would be to take the truck to a Ford dealer.
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Katidid (08-01-2021)
04-03-2015, 11:45 AM
#13
Not sure on the fix but thanks for the info on not having to pull the bed. Do both tanks not take gas? You could go to a junk yard and pull a couple filler necks since you know how to do it and not pay much. I'd try that and see if it fixes it. Btw the tank on mine that doesn't like to take gas is the rear which is the one guage in the truck that does work. Figures. I was able to put gas in it but you can tell there is too much pressure. It only shut off a couple times and I got 8 gallons in but when it shut off at about 8 gallons it sprayed back a little so something isn't right
04-03-2015, 12:09 PM
#14
Member
Thread Starter
Yeah. Both tanks will not take gas properly. As soon as I begin to pump gas it will click in a second. Only putting in cents at a time. Lol. It's crazy. And making me crazy at the same time.
04-03-2015, 09:04 PM
#15
Yeah that's obviously something that would drive anyone crazy. Odd that it's both tanks at the same time. Do u hear it gurgling when u try to add gas or does it shut off too quick?
04-10-2015, 01:00 PM
#17
Senior Member
it needs to be long enough that it will not falll into the tank if you let go. And STRAIGHT ... no kinks or hooks on the end.
I specify piano wire, but any very stiff bare wire will do. use a knife sharpening stone to smooth/round the leading point so it does not catch as you insert it in the vent tube
good luck! i hope that fixes it
08-08-2021, 02:08 PM
#18
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Even after 6 years, there's no advantage to starting a new thread for a related problem on the same truck.
Gas takes years to go bad - like more than 5 because I've let some of my trucks sit that long without problems. A few months is nothing.
Sound is not a test for a fuel pump. They don't all sound the same, and their sounds can change randomly. The only test is pressure at the fuel rail, using a gauge with the key in RUN and a jumper wire in the DLC:
(click this text)
(click this text)
If it has no pressure, the first step is NOT to pull the bed or buy a new pump. You can't simply "think" what's wrong with a vehicle - you have to diagnose, test, & measure. The first step is to measure voltage across the pump wires at the tank connector (jumper & key again):
(click this text)
If that fails (<10VDC), the next step would be to test the FP relay voltage. All its wires should be >10VDC except its trigger/ground which should be ~0VDC. This page has the wire colors, but ignore the pin numbers.
(click this text)
If the relay fails to click on when energized, unplug it & install a jumper wire between the B+ & inertia switch terminals in the harness connector. If that brings up the fuel pressure at the rail (or voltage at the tank connector), replace the relay. I highly recommend NOT buying the same style that plugs in. Read the PREVious 2 pages from that last one and swap both relays to the Bosch/ISO/Tyco style.
If jumpering/replacing the relay does NOT bring up pressure, measure voltage at the tank. If it's now B+ (~12VDC), the pump is likely bad. If it's not B+, test at the tank switch & the inertia switch.
Hello. I have a 1991 Ford F-150 with a possible fuel pump issue and/or fuel pump electrical issues. My issues started with this thread here and now after taking a break from working with this truck I added a new battery, removed all gas from both tanks as the little gas it did have was put in months ago, and now I'm troubleshooting a new problem. Usually when I turned the key I would hear a buzzing sound, presumably the fuel pump working, and the truck would start and run easily. Now with a fresh battery installed, fresh gas in the rear tank only, I don't hear that sound. I immediately begin to think this is a bad fuel pump and now I need to drop the tanks and start replacing it all since I was already having issues with the fuel system before. After doing some research online and seeing a few posts here and there some have said before removing the bed and removing tanks, etc. to check the fuel pump relay, check the EEC power relay, check the inertia switch, and lastly I saw some post about a fuel pump driver module. I don't have a multimeter to test these relays as some post suggest and I'm not even sure if this year (1991) has a fuel pump driver module. I was able to check the inertia switch and it's pressed down as needed. I did remove the fuel pump and EEC power relay to see the connections and there was some slight corrosion on the relays and on the connection itself. I tried blowing out the corrosion and some corrosion has been removed but by all means is not completely free of corrosion. I want to eliminate all possible electrical issues related to the fuel system before proceeding to have someone replacing the fuel pumps. I know I don't have the knowledge and tools to complete such a job. Assuming I just replace the fuel pump and EEC power relays what are some other steps I can try to see if I'll hear the buzzing sound of the fuel pump when I turn over the key? Does the 1991 Ford F-150 have a fuel pump driver module or not?
Also I noticed that when I turn the ignition switch I only see the battery light lit up on the dashboard. I can't remember if I'm supposed to see other lights on the right side displayed as well. Should I be seeing other lights on the dashboard light up when I turn the ignition switch?
Thanks for taking the time to read all of this. I'm doing my best to research online the possible issues before reaching out to various mechanics for local help on this. I'm sure it will be costly repair in the end.
Also I noticed that when I turn the ignition switch I only see the battery light lit up on the dashboard. I can't remember if I'm supposed to see other lights on the right side displayed as well. Should I be seeing other lights on the dashboard light up when I turn the ignition switch?
Thanks for taking the time to read all of this. I'm doing my best to research online the possible issues before reaching out to various mechanics for local help on this. I'm sure it will be costly repair in the end.
Sound is not a test for a fuel pump. They don't all sound the same, and their sounds can change randomly. The only test is pressure at the fuel rail, using a gauge with the key in RUN and a jumper wire in the DLC:
(click this text)
(click this text)
If it has no pressure, the first step is NOT to pull the bed or buy a new pump. You can't simply "think" what's wrong with a vehicle - you have to diagnose, test, & measure. The first step is to measure voltage across the pump wires at the tank connector (jumper & key again):
(click this text)
If that fails (<10VDC), the next step would be to test the FP relay voltage. All its wires should be >10VDC except its trigger/ground which should be ~0VDC. This page has the wire colors, but ignore the pin numbers.
(click this text)
If the relay fails to click on when energized, unplug it & install a jumper wire between the B+ & inertia switch terminals in the harness connector. If that brings up the fuel pressure at the rail (or voltage at the tank connector), replace the relay. I highly recommend NOT buying the same style that plugs in. Read the PREVious 2 pages from that last one and swap both relays to the Bosch/ISO/Tyco style.
If jumpering/replacing the relay does NOT bring up pressure, measure voltage at the tank. If it's now B+ (~12VDC), the pump is likely bad. If it's not B+, test at the tank switch & the inertia switch.
08-08-2021, 08:13 PM
#19
Member
Thread Starter
Thanks for all of the info. One other thing I'm noticing is that when I turn the key up I only see the battery light, I don't even see a Check Engine light. What would be causing that? Maybe the issue I'm having is at the ignition?
I have read many posts and I see some mention the EEC power relay which is next to the fuel pump relay under the hood. I'm just not sure if that could be tied to the no check engine light.
I have read many posts and I see some mention the EEC power relay which is next to the fuel pump relay under the hood. I'm just not sure if that could be tied to the no check engine light.
Last edited by Atrocity79; 08-08-2021 at 09:32 PM.
08-10-2021, 12:06 AM
#20
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You need to put ALL your truck's details into your signature as this page explains, so we don't have to go looking back through the thread, or ask & wait every time, to know what vehicle you're talking about. Not just year; not just year & engine - every detail. Some of them aren't relevant to this issue, but you don't know which ones to leave out, and the others could be relevant to future issues, so just put them all in now.
(click this text)
Don't guess about what might be causing a symptom. Either ask, or read good documentation. Follow the links in this caption:
(click this text)
The most-likely reason that the CEL doesn't come on with the key is that the bulb is burned out. Remove the headlight & wiper ***** (a simple hook in the notch in the **** near the shaft)...
(click this text)
...pop out the lower panels, then remove the screws for the bezel & instrument cluster.
(click this text)
This shows how easy it is to release the speedo cable:
(click this text)
It just pushes back on.
(click this text)
Don't guess about what might be causing a symptom. Either ask, or read good documentation. Follow the links in this caption:
(click this text)
The most-likely reason that the CEL doesn't come on with the key is that the bulb is burned out. Remove the headlight & wiper ***** (a simple hook in the notch in the **** near the shaft)...
(click this text)
...pop out the lower panels, then remove the screws for the bezel & instrument cluster.
(click this text)
This shows how easy it is to release the speedo cable:
(click this text)
It just pushes back on.