Mechanics

EFI FUSE BLOWS

1995 Toyota Corolla • 1.8L 4 cylinder 2WD Manual • 264,000 miles

Initially the rear brake lights blew brake fuse every 3 three weeks or so. Then later the EFI fuse blew. These circuits are not related electrically but physically can be traveling along the same harness for a brief period(?)
EFI: Problem
After starting up quickly (no problems) in about 4 minutes EFI Fuse blows. Mechanic really doesn't know what the problem is (Firestone). First they said the alternator was spiking to 15.5-16. Volts but later changed their minds(?). Then they said it was the ECM or computer located behind front console somewhere(?).

The EFI circuit carries +12V to many circuits with the first being the EFI Relay coil. My daughter had mentioned a week before the EFI started blowing that the car was going through more gas all of a sudden. Maybe another coincidence that Winter gas is now pumping from tanks.

So is it the pump (do I have an electrical pump- intank or?) Something is heating up in 4 minutes to blow this EFI fuse but before then I have no problem starting the car and it runs fine. Should I break the line going to the pump and place a fuse inline with that section of wire? Never had trouble with EFI or fuel system before at all. Thinking also of disconnecting the alternator and running off battery to see if that clears the problem -then there is something wrong with alternator but it is only 1 year old and has been charging the battery just fine. Still have original OEM fuel injectors, fuel pump, fuel filter. Plugs are platinum newer wires/cap/rotor.
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Condor19
December 2, 2013.



First, I would recommend that you confirm that the alternator is producing the proper amount of voltage. Most parts stores will check that for free. If you don't have on near by, you can do it with a volt meter. Just check the battery power with the engine off, then check it with it running.

If that seems okay, then I feel you have a fuel pump issue. Tell me this, when the fuse blows, do you have fuel pump pressure or is the fuse for the pump?

I'll need to check the schematics to see where pump gets its power from. In the mean time I'll check alternator's output voltage with my meter. It shouldn't go higher than +14.6? Or what voltage?

Condor19

Tiny
Condor19
Dec 4, 2013.
I would say right in that area, 14.6 v