Hi All, I'm working on my 1988 2.5L Value Leader. Can anyone tell me where I might get a replacement for the interior fuel tank sender/pump connector circled in red on here? The pin for the sender wire (purple/pink) is not making reliable contact and thus the fuel level sometimes pegs beyond full. I'd like to repin all 3 wires.
[This message has been edited by gjgpff (edited 01-09-2022).]
most times... the "pins" are standard and used in many other connections.
If these are what I think... uses a common "pin" that same as others inside the cabin.
Carefully release TPA... push on ears holes on black part side then pull. (See my Cave, Terminal Access)
Terminal should have locking ear you push release tool in front and pull wire out back like this... See my Cave, Defect & Connection notes
If doesn't have major damage... Often cleaning and carefully pinching in right places will solve many problems w/o replacing.
Coat w/ brake or silicon grease. Is on top of so don't sit in gas that lets moisture eating w/o something block that.
If bad and need replacement, not sure who sells just the pins to DIY crowd. Might get pigtail kit for that or something w/ same terminals.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Ogre, Many Thanks! Yeah, I will definitely use your approach for pin removal and cleaning. I believe that the pins should be of a standard type, I'd just love not to have the hassle of repinning.
For some reason the system won't let me add a proper image to my original post so I'm going to try again:
And here's an image of the connector removed, showing the three pins for power (grey), ground (black), and signal (purple/pink)
After a bit of poking around on the web, it looks like the connector is kind of a Molex type, but I could be wrong.
Any help is appreciated, thanks!
[This message has been edited by gjgpff (edited 01-01-2022).]
Is Not a Molex or other standard types for electronics.
All connectors are GM parts made by Packard Electric Div of GM later Delphi. Some pins are available, others not easy to find thru regular retail. (Some now hard for even thru GM Dealers Service.) Many plugs are only sold as pigtails thru parts stores often as Dorman parts.
Some pins maybe compatible w/ other electronic parts but often not and why some people put on generic spade ends etc.
Are notes in FSM and other how to take apart but often doesn't cover all connectors w/ exact details.
[This message has been edited by theogre (edited 01-01-2022).]
Thanks! I may have to employ something like that sooner rather than later! By cleaning the contacts and the connector I was able to get the impedance on all three connections: power, ground, and sensor, to ~1ohm or less. I put the sender/pump back in the tank and the tank back in the car. I reconnected the battery and the the fuel pump fuse.
The engine started right up the first time and ran/idled for 15 min or so. I drove the car to turn it around and everything seemed to be working, and my fix to the fuel level sender had worked!
However, on the second attempt the car wouldn't start, I cranked it several times but it didn't catch. I let it cool and tried again: crank but no start.
I'm going to have to start a new thread to diagnose this problem. It's possible the fuel pump replacement was unnecessary and the issue is somewhere else. I probably should have done more diagnosis before I pulled the tank, but I already knew I wanted to fix the sender.
Back to the drawing board! I guess I should start a new thread, right?
You can measure the resistance in ohms between the tan/white wire in the ALDL connector (behind the cigarette lighter) and the body of the car to check your repair. The reading should be under 100 ohms (probably quite a lot lower). BTW, the male connector in your picture looks very dodgy and may not be reliable, even after cleaning.
I think OE is GM/Delhi 56 Series "spade" end use by so many plugs to list. Same end but different plastic for whatever part goes to. Can get them because still in use by GM and many others but not in small quantities from many vendors.
Above RACETRONIX part is a pigtail kit made of GM/Delhpi Metri-Pack plug and socket. Is 150 pull to seat series and rated 14a but you don't want pull more ~ 10a max for long term use.
quote
Originally posted by Rexgirl: You can measure the resistance in ohms between the tan/white wire in the ALDL connector (behind the cigarette lighter) and the body of the car to check your repair. The reading should be under 100 ohms (probably quite a lot lower). BTW, the male connector in your picture looks very dodgy and may not be reliable, even after cleaning.
Measure Ω that ways isn't good.
Tank ground wire end is actually in the cabin. See my Cave, Wire Service
Measure Ω between ALDL G and frame then measure across the motor and more will give bad values. That's even if you get good connection w/ meter to frame.
So, I went back to first principals yesterday and attempted to start the car again. Here's what I found 1) I didn't hear the fuel pump prime when the key was turned to the (first? second?) position, so that's not good. 2) The car would crank easily but not start. I saw the oil pressure gauge go to 50-ish, so the auxiliary circuit should have closed (but maybe there's an issue with the oil pressure sensor/aux fuel pump circuit) 3) I didn't notice any fuel in the throttle body after repeated cranks. 4) The car would start when I sprayed starter fluid into the throttle body. 5) I then tried to check the voltage between the ALDL ground pin (bottom left as one looks at the connector) and the top right (tan/white). I never got more than like 0.3V, so that's not good and may be, according to the service manual, indicative of a bad relay.
I've ordered two relays (one spare) from Rockauto and will continue testing.
quote
Originally posted by Rexgirl:
You can measure the resistance in ohms between the tan/white wire in the ALDL connector (behind the cigarette lighter) and the body of the car to check your repair. The reading should be under 100 ohms (probably quite a lot lower). BTW, the male connector in your picture looks very dodgy and may not be reliable, even after cleaning.
I agree it's less than a perfect connector but I got consistently less than 1 Ohm resistance for each of the lines passing through the connector. I'm thinking I might spring for the Fiero Store sender unit just to put all this to bed, if it turns out that that's the problem.
Yeah, that is a concern. I'd read that page when I was just contemplating my current fix and before my current issue. My sender issue is that ever since I got the car in June 2020, the fuel gauge needle only traveled from Full, when the tank is full, to half-full and then stopped. I now believe I know what was causing the problem. I believe that, due to corrosion in sensor and/or ground wires, there was residual impedance in the line. This impedance, lets say 30-50 ohms is sufficient to keep the needle at half way, even if the sender's float is at the bottom of the tank. I believe that my fix, which is imperfect, has probably mitigated the residual impedance, at least a little and maybe a lot because the needle is now at 1/8 full and there's about 2-2.5 gallons in the tank. However, I still have the main problem, which is that the fuel pump isn't working.
I'm contemplating the following now instead of getting the Fiero Store Sender: If I am able to figure out why my fuel pump isn't starting, even if it isn't due to anything in the tank I'd like to do the following:
1) Replacing the connecting wires with that setup from Racetronics, it looks sweet. 2) The steel pressure line from the pump out of the tank was severely pitted where it was joined to the pump by a short length of submersible (hopefully!) fuel line. I'd like to cut that steel line above the pitting and replace it with a short new length of 3/8" mild steel tubing. I have a buddy who makes a living at welding/brazing, etc. I mitigated the pitting with rust removal and JB Weld and some wet sanding to smooth out a sealing surface, but if I could attach new line I'd eliminate that potential source of issues.
What do you think of 2? Is it realistic to weld/braze a short length of 3/8" mild steel fuel line there? I guess I could ask my buddy. I will update this with pictures tonight. Are the fixes I'm contemplating going to get me a sender/pump apparatus that's as good as the Fiero Store's?
[This message has been edited by gjgpff (edited 01-06-2022).]
2) The steel pressure line from the pump out of the tank was severely pitted where it was joined to the pump by a short length of submersible (hopefully!) fuel line. I'd like to cut that steel line above the pitting and replace it with a short new length of 3/8" mild steel tubing. I have a buddy who makes a living at welding/brazing, etc. I mitigated the pitting with rust removal and JB Weld and some wet sanding to smooth out a sealing surface, but if I could attach new line I'd eliminate that potential source of issues.
What do you think of 2? Is it realistic to weld/braze a short length of 3/8" mild steel fuel line there? I guess I could ask my buddy. I will update this with pictures tonight. Are the fixes I'm contemplating going to get me a sender/pump apparatus that's as good as the Fiero Store's?
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Given the amount of labor to remove and reinstall a tank along with consequences of shortcuts, I'm in favor of replacing the entire top piece. I went through this a few years ago with pump problems, sender problems, melted connector problems, relay problems, etc. Even though I got to be proficient at draining the tank, removing, and reinstalling it, I finally resorted to top quality components and tested everything on the bench as well as under the car before actually installing it in place. My budget allowed it and I realize this approach is not for everyone.
The tan/white wire in the ALDL connector sends voltage directly to the Fuel Pump's positive terminal (through a connector on the firewall under the rear window). The pump's ground wire runs from the pump to a ground between the seats at the rear of the center console as Ogre wrote. If power is applied to the tan/white wire, and the pump has a good ground (and the pump itself is good, of course), it should run.
[This message has been edited by Rexgirl (edited 01-06-2022).]
The tan/white wire in the ALDL connector sends voltage directly to the Fuel Pump's positive terminal (through a connector on the firewall under the rear window). The pump's ground wire runs from the pump to a ground between the seats at the rear of the center console as Ogre wrote. If power is applied to the tan/white wire, and the pump has a good ground (and the pump itself is good, of course), it should run.
Please forgive my ignorance, I'm only just now getting to grips with the electrical aspects of the car. I think you are suggesting that I need to turn the key to the first position and run a wire from, say, the cigarette lighter to the port "G" (usually the top/right location) on the ALDL and listen for the fuel pump, right? My reading of the schematics suggests that the fuel pump relay is between this "G" location and the actual fuel pump, is this correct?
1) If the cigarette lighter is the right approach, how should I rig up a wire? Any suggestions? I could use a small 12V battery but that may not have enough current to really get the pump going, right?
[This message has been edited by gjgpff (edited 01-06-2022).]
Yes, can test FP by putting "12v" to aldl G but make sure is really G. Aldl can be installed w/ "key" up or down and that affects pin layout. See my Cave, ALDL/ALCL
Many use cigarette plug. If you short out cig plug trying to this, might blow the bat fuse or other problem...
FP draws ~ 7-10a. Bat fuse is 20a
Safer is likely pull the socket (2 screws) to pull power plug off back. See my Cave, Lighter
Please forgive my ignorance, I'm only just now getting to grips with the electrical aspects of the car. I think you are suggesting that I need to turn the key to the first position and run a wire from, say, the cigarette lighter to the port "G" (usually the top/right location) on the ALDL and listen for the fuel pump, right? My reading of the schematics suggests that the fuel pump relay is between this "G" location and the actual fuel pump, is this correct?
1) If the cigarette lighter is the right approach, how should I rig up a wire? Any suggestions? I could use a small 12V battery but that may not have enough current to really get the pump going, right?
Yes, you should be able to use power from the cigar lighter, which is hot/live all the time. The lighter is protected by a 25 amp fuse (along with the radio, among other things), but obviously be careful with a live 12 vdc wire. Perhaps use an 18 gauge wire and an insulator sheet over the console metal? Also, it may be easier to access the cigar lighter's wire by disconnecting it from the lighter housing. You might wish to leave the ignition off, to simplify your first pump test. I would suggest making your initial ALDL connection brief, just a second or two, or long enough to hear if the pump is running. Doing an ohm test before applying power would be a little wiser, still, just be ready to disconnect your jumper wire if needed.
[This message has been edited by Rexgirl (edited 01-06-2022).]
All, I measured the impedance between the "A" (Ground), and "G" (Fuel Pump) ports of the ALDL and it's consistent at 2 ohms, so I got that going for me, which is nice.
I then unscrewed the retaining plate on the cigarette lighter and, when I disconnected the 12V orange wire, I was able to put an alligator clip on the orange wire's connector. I connected to the copper wire I stuck in the "G" (Fuel Pump) port of the ALDL with an alligator clip on the other end from the 12V source, and I could hear the fuel pump running. I did this for a few seconds two more times to make sure, hearing the fuel pump run both times. After that, I pulled my stub copper wires, connected the cigarette lighter back up and screwed the cover plate back on the ALDL interface. I tried the ignition and got the same result, crank and no start.
So, now I know that my fuel pump is probably both running and fairly well connected up. I'm thinking the next step is to see if there's an issue with the fuel pump relay.
[This message has been edited by gjgpff (edited 01-07-2022).]
That's good news that your pump is running. Hopefully the pump is delivering adequate fuel volume and pressure. Yes, it sounds like you may have both a failed relay, and oil pressure switch. Both provide power to the fuel pump (at least in the 1987 Duke according to my '87 FSM), although the engine can run with only the FP relay (or OP switch).
[This message has been edited by Rexgirl (edited 01-07-2022).]
Thanks! Yeah, it does look like it's the relay and the oil pressure sensor. In fact I strongly suspect that the FP relay hasn't worked in all the time I've had the car because I have always had to crank it a lot in order to get it to start and it always starts when I see the oil pressure get past ~40 to ~50 on the gauge. I'm going to try to get the relay to work first. Apparently it may not be the best thing in the world to rely on the oil pressure sensor to supply power to the fuel pump:
It's a sunny morning here in California. The relays arrived yesterday. I removed the old relay, cleaned the connectors with Permatex Electrical Contact and Parts Cleaner and replaced the relay.
The car started up without any issues. I couldn't hear the fuel pump prime or the relay click, but where I was working on the car is quite loud, even on a Sunday Morning. My hearing isn't what it used to be and the dinging of the "Brake" signal didn't help! I let the car idle for 25 min to help charge up the battery and subsequently was able to start the car two more times, again I didn't hear the relay, or the prime. Tomorrow I'll have a helper, (and maybe take the hand-brake off!) to make sure that the relay was the fix and not just that the oil pressure sensor decided to start delivering power to the fuel pump again.
The oil pressure sensor is arriving on Monday so I'll have a backup thing to try. I'll wait until I have the cable to the pressure sensor and replace that along with the sensor.
Things are looking up. If I hear the relay, I'm going to drive the car.
Again, thanks to everyone who helped me with this!
[This message has been edited by gjgpff (edited 01-09-2022).]
Thank you for the update, and I've got my fingers crossed that the new relay will get your Fiero back on the road (it should). IIRC, I never heard the FP relay click in my Mera (though I only listened closely during a check out shortly after purchase and that was over eight years ago), and I'm fully certain it was working.
