zero503

i picked up a 90 or 91 4runner 3vze 5spd 4wd that the motor had already blown up in, he swapped in a newer 3vze in and could never get it started, iv replaced the main relay, fuel pump, dizzy, plugs and wires, and the main relay, when i got to turn it over it starts for a second or two then shuts off and wont start again till i turn it all the way off then it still dies every time, if i unplug the cold start injector it doesn't even do that much. i hooked up a scanner to it and it is getting a no rpm to crank sensor code 12, which is why i got the new dizzy but still the same i had gotten a diff ecu from a wrecking yard but its the wrong one. the only things i can think of is the COR or the ecu, any ideas? thanks.

zero503

anyone? bump.

scope103

Punctuation would help, but it sounds like you installed what you knew was the wrong ECM. Any reason to think it will work?

Since you're getting a code 12, I would take a cue from the FSM and look at the NE and the STA signal at the ECM.

But if those signals were out completely, I would expect no ignition at all. A common cause of "start and run a few seconds" is a problem with the VAF switch to the COR. Fortunately, this is trivial to diagnose: hold the fuel pump on with FP+ terminal in the diagnostic plug; if it runs then it is either the VAF or COR.

Otherwise, I would still suspect the ECM is telling the truth, and go from there rather than replace parts randomly.

zero503

okay so put a jumper in the fp+ to the batt?

zero503

never mind im stupid, so i put a jumper in the b+ to fp and the fuel pump turns on with the key but it still starts for a second then dies, its getting fuel to the fuel rails but the injectors are not pulsing. what other than the ecu controls the injectors?

"Punctuation would help" ya i spell werds rong too lol. and thanks for the help!

zero503

Okay so it was the ecm/ecu i plugged in the 91 specific ecu and it fired right up! thanks for the grammar lesson but i think i still suck at it.

edit, the wrong ecu i got was for a 90 which is what the last owner said it was.