I got a spare computer for my Buick for $25 at the junk yard. I would swap it out if I suspected a computer problem but it never was.
My 90’s Corolla has all the injectors tied together, and pulses them with just one driver transistor. The fuel injection is not sync’d directly to the piston position for each cylinder in other words. Of course the transistor the engineers selected is capable of doing that. On newer car like OP’s usually the FI is sync’d so there’s a separate driver transistor for each cylinder or pair of cylinders. But doubling up should work at least functionally, although it might cause emissions or mpg deviations from ideal. Whether the driver transistor can power two injectors for any length of time, OP will soon find out.
unless i am missing something (which totally could be,) it sounds as if OP ran a constant ground to Inj #1, instead of a ground controlled by the ECM for inj#1.
Repair the original ground (take away your original “fix”,) and from what I am reading, I think all would be good.
Bad ground originally kept inj #1 from firing.
run new ground, replace ECM
now inj #1 constantly fires
this tells me ground is wrong.
1 Like
No, he tied #1 and #3 controlled grounds together.
My understanding is the OP believes one injector driver transistor has failed, which resulted in that injector always being turned on 100%. Rather than fixing the driver transistor by repairing or replacing the ECM, OP has tied two injectors to one of the good driver transistors.
Or if a little handy, solder in a new transistor for $2 if it still uses regular transistors.
I think Eddo means BEFORE op tied $1 and #3 together. I like his idea.
1 Like
I know for sure its a bad driver not my wiring fix. I’ve tested and tested it all comes back saying the same thing. I don’t have a new ECM yet but the temp fix is still working for now until I get one.
The wire I ran ties in just before where it bunt and back in a little after. so I know thats not the problem.
which is less bad? unplugging injector that is stuck open so it is always closed? or having that injector fire out of time?
I’d guess an injector stuck 100% open is much worse than one squirting the right amount of fuel, but out of time. My Corolla’s injectors are all tied together by design and that method works fine for the 4AFE engine anyway. There may be some design modifications to the 4AFE intake valve area to accommodate for the fuel hanging a round until the valve opens though, which might not be present on OP’s engine.