Fuel Problems(Kinda)
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Fuel Problems(Kinda)
Well I have an 88 n/a but the motor is a 1990 n/a with 88 ecu and 86 wiring harness with no OMP and no emissions at all no bac no nothing everything has been bypassed, But my question is why would my fuel idiot light not work and also could this also be why my fuel gauge is off by almost quarter of a tank?
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My guess is it's a problem somewhere in the ECU itself (although I am not sure if S4 and S5 ECU's were much different), or the cold solder joints on the idiot cluster itself. 99.9% of the time, those are your issue for those lights. As for the fuel level, you're going to want to check your pump assembly in the hatch, and see if that is giving you problems reading the level.
Side note: Get yourself another BAC, it was there for good reason, and should be kept.
Side note: Get yourself another BAC, it was there for good reason, and should be kept.
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My guess is it's a problem somewhere in the ECU itself (although I am not sure if S4 and S5 ECU's were much different), or the cold solder joints on the idiot cluster itself. 99.9% of the time, those are your issue for those lights. As for the fuel level, you're going to want to check your pump assembly in the hatch, and see if that is giving you problems reading the level.
Side note: Get yourself another BAC, it was there for good reason, and should be kept.
Side note: Get yourself another BAC, it was there for good reason, and should be kept.
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#11
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Both the fuel gauge and the low fuel lamp are using variable grounds (just like the oil pressure and water temp gauges, actually)...most likely culprit is going to be the sending units or the bulkhead connector at the tank.
If you disconnect the 4 wire plug at the tank, with the key to ON, you should get +12v at both the fuel and low level wires.
If yes, it's your sending units in the tank.
If no, start working back to the dash and find out why.
Also, as long as you're there, make sure the 4th wire in the connector, which is the ground for both sensors AND the fuel pump, has good continuity to the chassis.
The BAC and ECU have absolutely nothing to do with it.
EDIT: It's been a while since I've been in that area of my car...there may be a ground wire connected to the bulkhead plate, separate from the connector itself (although I'm pretty sure it joins the fuel pump ground in the harness)...make sure that's clean/tight as well.
If you disconnect the 4 wire plug at the tank, with the key to ON, you should get +12v at both the fuel and low level wires.
If yes, it's your sending units in the tank.
If no, start working back to the dash and find out why.
Also, as long as you're there, make sure the 4th wire in the connector, which is the ground for both sensors AND the fuel pump, has good continuity to the chassis.
The BAC and ECU have absolutely nothing to do with it.
EDIT: It's been a while since I've been in that area of my car...there may be a ground wire connected to the bulkhead plate, separate from the connector itself (although I'm pretty sure it joins the fuel pump ground in the harness)...make sure that's clean/tight as well.
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