2002 misfire after warm start

From what I can tell, you might be able to get to it from the bottom. The Haynes manual says you have to remove the inverter like Chapman says but, definitely verify its bad first.

Remember, all of what I posted is simply theory and not based on facts. I could be totally wrong about this but, it does make sense. You should be able to read the voltage at pins 19 gnd and 28 signal of the Engine ECM. You may have to make some leads that fit into the back of the plug. I would recommend a long single strand of copper wire wrapped around the tip of your test leads and jammed into the proper pins (at the back of the connector).

Good luck.

 

I've been happy with these OTC backprobes.

But honestly, before standing on your head to stick wires in dark places, have you read the coolant temperatures out of the ECM yet? The Scangauge II is cool (and you can buy it right from the PriusChat shop and support the forum), but as engine coolant temperature is one of the OBD-II standard parameters, any scan tool should be able to read it, like the one at your local auto parts place. Just put it in live data mode and watch the coolant temperature while you start and warm up the engine, and find out whether the readings make sense while sitting in comfort instead of doing contortions with meter probes.

-Chap

 

Sorry it has taken me a while to reply but yes mine was doing exactlythe same as yours. Changed the crank sensor & everything was running fine then 2 weeks ago I stopped at a cheaper gas station due to the higher prices & the car got 100% worse never stops misfiring or vibrating now. Was sure I got some bad gas but ran the cleaner through with no results. I think my next step is to replace the coil packs as mentioned above. The only reason I was even attempting this is because the dealership wanted $7000 & that was "just to start" might not fix anything. I decided to change sensors & drive the car till I couldn't anymore. The mileage now is very bad only getting about 28mpg & that is no better than many regular cars. If anyone else has any repairs or fixes for this please post. I'll be checking back regularly

 

I have now changed the coil packs on all four with no help. My plugs are getting worn pretty quick now too even though I just changed them about a month ago. My Prius is now misfiring almost constantly & even in idle. In fact what it does during the idle until the all electric kicks in reminds me of what they call deseling. If anyone has any more suggestions I would appreciate it

 

I got the triangle & the car with the (!) today would hardly go & finally died on me. when I finally got it to start again it had the turtle but could not get it to move. The battery has been showing only half most of the time lately sometimes going to 3/4 or 1/4 but pretty much staying on 1/2. Today it was at 1/4 & didn't seem to want to go any higher. due to not being able to get it to move I can't get codes. Do you think the problem is in the inverter maybe? I know the rattling noise is coming from under the hood somewhere. Will the battery cause the random misfires? or will the misfires cause battery problems? The dealership checked the 12v & said it was good. Please any input will help!

 

If your car's engine problems started immediately after you refueled, then it seems reasonable that you had pumped bad gasoline - perhaps even diesel fuel? That is further confirmed by your saying that the engine is "dieseling". The use of fuel injector cleaner is not going to fix the bad gasoline.

The fix is to drain the fuel tank. The easiest way to do that is to disconnect the fuel line where it attaches to the fuel rail in the engine compartment, attach an extension to the fuel line so that you can drain the bad fuel to a container, and run the fuel pump to pump out all of the bad fuel.

To run the fuel pump, you need to find the circuit opening relay in the relay/fuse box near the inverter, and short the switched terminals to energize the fuel pump. If you have any question about how to do that, I suggest you obtain the electrical wiring diagram for your model year at techinfo.toyota.com so that you don't cause more harm to your car.

It may be necessary to replace the fuel injectors if they are clogged, but the first step should be to ensure that your car has high quality gasoline in the tank. Good luck.

 

NewBy, have you heard of Mellor's Automotive in West Melbourne? They are a hybrid specialist, not too far from you.

I don't know if you checked this, but the primary source of engine problems is the throttle plate sticking in the bore. You must manually clean it, as fuel system cleaner enters downstream of it.

 

Patrick I may have gotten bad gas but it wasn't diesel unless it was in the wrong tank. I filled it with premium that time because it was coming from a Walmart station. But my car had been doing the exact same thing as the OP's when I actually started having problems. I cleaned the Throttle body at that time, changed the crank sensor & the knock sensor & after that it seemed to be running fine with no problems till I filled with the Walmart gas. It does not actually diesel just reminds me of that as my car is supposed to be in idle when it does it. It is just that jerky about to cut off thing that a car does it reminded me of. But I will try the empty the tank. Thank You.

Seilerts I don't know of them but I will check them out. I should be able to get their info & directions online & thank you been looking for someone besides the dealership which I think is really in the dark more than I am & I am not mechanically inclined. But the info I have been getting here has helped to relay to my son-in-law who is.

 

Ok have just changed the fuel injectors & the car seems to run perfect. Milage is back up & battery is now staying full. The injectors must have gotten fouled at some point whether this was the problem initially or after the fill up at Walmart I don't know but hopefully the problem is now fixed. At least that one had the wheel hub go out on passenger side so had to stop with the misfire experimenting to fix that now I think the driver side may be going but at least that is something the tire shop will fix for a reasonable amount!!! Hope this will help any others out there with a similar problem. I found the fuel injectors on ebay for $130 for remanufactured set.