Misfire cylinder 1

Clark, I was wondering if you ever resolved this problem. I have the exact same one! Did a lot of the things mentioned. The light also goes on and off as it pleases. Car runs fine, 50MPG.

 

i wonder if it could be something as simple as a loose connection.

 

Having read this thread I would suggest the fault code is happening not because of a misfire on cyl 1 but becuase the ECU *thinks* there is a misfire on cyl 1. Perhaps that side of things should be investigated - an actual misfire is all but ruled out by now (coils swapped, injector replaced, no wear)

How does the ECU detect a misfire on any cylinder? If we can know that, maybe we can start to figure out why it thinks there is a misfire when there isn't.

 

You may be right about the ECU thinking there is a misfire. If I get a chance next week I will got to the junkyard and get another ECU and see what happens.

 

The engine ECU uses the crankshaft position sensor to detect engine speed variations which are indicative of misfire, and the camshaft position sensor to identify the misfiring cylinder(s).

 

I have had misfire issues with cylinder #1 twice now. The first time, at about 205,000 miles I removed the coil and spark plug, cleaned and dried both of them and re-installed them. Misfire GONE. about 60,000 miles later the misfire was back. I repeated the procedure and when I was replacing the coil, I noticed that when the coil retainer bolt was fully tightened, the gasket between the coil and the valve cover was not compressed like it was on cylinder #2. In fact, there was a gap that was allowing water, grime and dirt to enter the tube and cause the misfire problem. It looks to me that the threaded post for the retainer bolt is too long on cylinder #1 and not allowing the gasket to seal. I filed the underside of the bolt hole on the coil to allow the coil to seat deeper into the tube and now the gasket compresses. I hope it seals now. Timew will tell. Is there anyplace where I can purchase new coil gaskets without having to purchase the entire coil?

 

what can i do if dont have ground injector 2

 

The common denominator is the dealer removed and reinstalled the head on the short block- I am suspecting a head gasket leak on that cyl- which is why the engine runs rough at start up after sitting overnight. After running a few minutes, the coolant burns off and the engine runs OK, until the radiator gets hot and under pressure and hot coolant leak starts the miss fire again on the plug. Naturally, if it is the head gasket, the dealer who did that short block swap should have to redo the head gasket. If there is any loss of coolant or overheating, look out.

 

The Toyota mechanic who did the faulty repair, would have his check docked for the hours it takes to replace the head gasket, if it was a reputable dealer who stands behind their work. No mechanic likes to have his check docked, but that is the downside for working on flat rate, not by the hour. It's possible, the owner declined to have the head rebuilt/surfaced flat ( to save money) and in that case, the dealer has an out= the head was warped and the gasket wouldn't seal.-

 

I think Clark Griswold stopped replying, but I'm having a very similar issue. Misfire on cylinder 1&2. I've had my Gen 2 prius for about 3 years now, and it was running perfectly until last week. My husband had bought some non ethenol gas for the hurricane, but we wound up not using it for the generators, so he put a bunch of it in my car. Gas wasn't old, and was stored in the garage. The next morning I went to the car to drive it and it sounded kind of rough when I started it. I drove it a block down the road when it started shaking violently. I immediately turned around and went back to my house. When I pulled up, triangle of death came on with all the other dash lights. Code was P3190 "loss of power". I replaced my spark plugs, cleaned the throttle body which was very dirty, changed the mass air sensor, cam sensor, cleaned fuel injectors, pumped the old gas out of if, filled it with new gas, and now I'm getting a misfire on 1&2. I ordered new coil packs as a last ditch effort. Anyone got any thoughts? Oh, and as a last mention, we had put some of that non ethenol gas in my daughters Mazda, and it threw the same code and was having loss of power shortly after, but resolved itself. My car was on empty when he used the gas in it, but the Mazda was only half a tank low. Her car sorted itself out.

 

did you run it long enough to get the old gas out of all the lines?

 

What was the octane rating of the non-ethanol gas?