What usually causes P1300? Replaced all three coils(OEM), 3 month old Denso plugs and NGK wires. Igniter is good. Swapped 2 and 4 spark plugs, swapped new coils. No change


Thanks
My long thread on TN:
1mz-fe, Starts then dies. - Page 8 - Toyota Nation Forum : Toyota Car and Truck Forums
Also the car will run, at 2000rpm with CEL flashing.

 

What have you tested, what parts have been replaced?

The codes are not necessarily related to ign problems, they just mean a multiple or random cylinder misfire is occurring.

The CEL flashing means the misfire rate is large enough to cause the catalytic converter to overheat and damage it.

Other possible causes are:

Injector problems
Fuel pressure
EGR system
Low compression
Incorrect valve clearance
Valve timing
MAF sensor
Engine coolant temp sensor for computer
Wiring or connector issues
Computer

You state the engine starts then dies, is this true?

Does the engine stay running if you keep the RPM at 2000? How does the engine run at this RPM, rough, OK?

Did you ever test the engine coolant temp sensor for the computer?

 

I tested the MAF, ECT for EFI sensor, Camshaft Position Sensor, Power coming to the igniter, power at the IGT terminal at the ECU, front injectors. All of these have the resistance in spec, and voltage at the connectors.

Yes, the engine will die if I don't hold the rpms at 2000-2200. It runs a little rough and I can smell gas. I checked for spark a the cylinder 2 coil with a screwdriver and there was a blue spark. And without the spark plug wire in cylinder 5 the car will barely even start. I am sure there is spark at cylinder 2 and 5, so is something else causing misfire on these cylinders.

 

Toyota had a TSB out for this car, codes, problems resulting from bad coil packs but you changed these.

Any vacuum leaks?

EGR valve stuck slightly open?

 

I checked for vacuum leaks, found none, hoses are in good condition.

I cleaned the EGR Valve in December and replaced the EGR Position Sensor a couple of weeks ago. What we be the symptoms of a stuck open valve?

Still have the same CEL codes.