I have a 94 t100 manual transmission with the 3rz-fe. When I start the truck it seems to run fine for a split second then starts to misfire pretty bad. It does it through all rpms. Kind of smooth's out around 3200 but still there. It is throwing a code for the crank position sensor but I have replaced it and no change. It is firing on all cylinders with even compression across the cylinders and all the injectors are working as well. I changed the plugs, distributor, igniter and have had no change. Any other ideas that I may have missed. Also checked for vacuum leaks to no avail


Like the title says please help with any knowledge or an educated guess at least

 

Remember the code is for the complete sensor circuit including the ECM

Connector plug damaged ? corroded ??

ECM getting wet by chance??

Rodents chewed through wires ??

Bad ECM ground ??

Did you go with the Toyota Sensor??

The dreaded T100 curse !!

 

I've checked the wiring harness from the connector back to the ecu. Everything checks out. I tried two different sensors one being from Toyota and another from eBay. Same results.
No moisture in the cab and the only thing I may not have is a good ground. One of the bolts holding the ecu down broke off. I'll double check that next time I get a chance

 

The ECM does not ground through the case .

The ground is most often on the intake when new .

Now on my 3.4 a PO335 will turn off the fuel

 

Good to know. I'll check both the ground and double check the wiring on the crank position sensor this weekend.

 

I checked the grounds for the ecu and all is well.
I doubled checked the wiring from the connector of the crank position sensor back to the ecu and it is good too.
Im not sure what to think at this point.