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Hi all, I am trying to diagnose a crank no start in my 1990 NA FC. I have read on here that the fuel pump is supposed to be getting 12 volts while the yellow test connector is jumpered. Well, I am only getting 1.3 volts, and steadily decreasing the longer I hold the multimeter there. Black/white wire is getting 12.2 volts, red is getting 5ish volts... I can hear the circuit opening relay clicking when I put the jumper wire into the yellow connector. Any ideas on where to go from here?
PS: side note that may be important: the car has been jumped backwards before. It ran fine after that, though.
thank you everyone for your patience and understanding.
Last edited by rotarynewb02; Nov 25, 2024 at 04:37 PM.
If you haven't already done so, than you might want to check the resistor/relay assembly located behind the right headlight. Here's a photo of the resistor/relay assembly.
If you haven't already done so, than you might want to check the resistor/relay assembly located behind the right headlight. Here's a photo of the resistor/relay assembly.
Fuel pump resistor/relay assembly.
Just checked it, all resistances good. It turns out the power wire is the black/white one, not the blue one.I must have read incorrectly on here a while back. Getting 12 volts to the black/white wire now! . I am optimistic. Should just need a new fuel pump as the car has been sitting for quite a while. Is there a write up on here on how to replace just the pump from the assembly? Hayne's manual only has a guide on how to take the whole assembly out and replace it. I have had the pump out before, just never done any maintenance.
Last edited by rotarynewb02; Nov 25, 2024 at 04:54 PM.
Correct. The power wire to the pump is Black/White and the ground wire is Black. Should be straight forward how to replace the pump. Otherwise, just buy a used pump assembly off Ebay.
Correct. The power wire to the pump is Black/White and the ground wire is Black. Should be straight forward how to replace the pump. Otherwise, just buy a used pump assembly off Ebay.
Gotcha. This car has been sitting for almost 2 years at this point. I know it is common for a fuel pump to fail due to sitting in bad gas for this long. Is it generally sufficient to just replace the actual pump itself instead of the whole assembly? (after flushing out old fuel of course). I will probably buy the CARTER P72165 from rockauto.
Gotcha. This car has been sitting for almost 2 years at this point. I know it is common for a fuel pump to fail due to sitting in bad gas for this long. Is it generally sufficient to just replace the actual pump itself instead of the whole assembly? (after flushing out old fuel of course). I will probably buy the CARTER P72165 from rockauto.
@rotarynewb02
hows that carter P72165 pump working out for yah?
I just ordered the same pump.
Gotcha. This car has been sitting for almost 2 years at this point. I know it is common for a fuel pump to fail due to sitting in bad gas for this long. Is it generally sufficient to just replace the actual pump itself instead of the whole assembly? (after flushing out old fuel of course). I will probably buy the CARTER P72165 from rockauto.
@rotarynewb02 any update on that new pump? Im still waiting from rock auto for the same pump
@Trueno102 I have been out of town for an extended period of time and haven't actually put it in. I just got back and ended up having to drop the tank to clean it out-- it was totally rusted. The pump came and looks good. I will give you an update when I get it in but I am still working on rust treating the tank. Should have the pump in and car turned on within the next week =)
@Trueno102 I have been out of town for an extended period of time and haven't actually put it in. I just got back and ended up having to drop the tank to clean it out-- it was totally rusted. The pump came and looks good. I will give you an update when I get it in but I am still working on rust treating the tank. Should have the pump in and car turned on within the next week =)
@rotarynewb02 I literally just went through the gas tank cleaning process. Ill tag you at the post i made.
. I am optimistic. Should just need a new fuel pump as the car has been sitting for quite a while. Is there a write up on here on how to replace just the pump from the assembly? Hayne's manual only has a guide on how to take the whole assembly out and replace it. I have had the pump out before, just never done any maintenance.
