Congratulations on your fix, Mike. Now I think I can add my list another example of an intermittent misfire caused by the partially clogged injector. As I have posted at the post #3, it was the injector which was causing the intermittent misfire problem.

I happen to have 2 oscilloscopes (diginal and analog) and I make it a rule to use those to check variety of parts. In case of an injector, I always measure the current and the spike voltage. The measurement helps to reduce the troubleshooting time a lot. In the past my method was not common and not to be understood by local car shops and dealers. But now I often have requests to come. To use electronics equipments such as an oscilloscope, spectrum analyzer, ESR meter, impedance analyzer and others are quite useful for the quick troubleshootings.

This is one of typical examples to find the exact cause of the problem. The shop owner spent more than a week to find out the root cause of the intermittent engine halt problem but he couldn't find any. Then he called me and I was able to find that the culprit was the crank position sensor in 20 minutes. The page is all written in Japanese but photos are showing how 2 oscilloscopes were useful to troubleshoot. Moderns cars definitely need to use an oscilloscope for troubleshootings. I always suggest shop owners to buy and use it. Only 1 shop did so. Others just say, "We call you". I hope some of you will start to use it. I'm sure you will find how useful to have and use it.

 

Well, this was resolved so I thought. Been driving the car with more regularity so the gas is fresher. The p0301 misfire remained mainly noticeable at idle or sub 1,200 rpm ranges. Pulled the ignition wire and the ohm reading is in spec with the other wires. The plug when removed had enough oil on the threads but the tip was clean and looked normal with no deposits. The valve cover gaskets and spark plug tubes had been resealed. The tubes themselves are clean, just a hint of some oil. That's concerning to find oil on the threading.

Thoughts on what to do with this particular cylinder?

 

i don't want to get ahead of myself but my tacoma had a misfire that would not go away after changing the plugs, and coils (coil on plug) - turned out the cylinder was losing compression due to bad valve seals :/ !

it might be worth doing a compression check/leak down but you're car isn't that high of a mileage eh mike? also i've never heard of a 1UZ with bad valve seals.

 

215K miles. Getting some good gas through the system took multiple fills so it had a variety of random misfires over the course. Hopefully there wasn't damage but still have to dig in and see why that cylinder is getting oil accumulation there. I'll do a compression check and see.

 

ah that's not too bad. my taco was pushing 240k miles on the original 2.4...way underpowered if you ask me!
i tried techron too for a few tanks but that was before i knew about the valve seals.

 

Went to do a compression check but my dial wound up being broken from sitting all these years.

Decided since that side was accessible I'd check each plug and clean the tube as needed. All the plugs on the drivers side had a coating of fresh oil on the threads. The tubes where the plugs seat had old gummy residue so that took some effort to clean up. I did not inspect the plug tubes after the shop replaced the valve cover gaskets so gauging by how sticky it was I suspect that was accumulated from the prior 200K miles. If it were fresh oil up there I would be pretty concerned.

Looking into the chamber I could see some a crusty build-up on the pistons. No bore scope unfortunately. No wet or oil coatings so that was a bit of relief. With the cleaned threads the engine started up faster. Will do the passenger side next.

At least gas prices are dropping a bit, was hard to fill up at $6.29 for Shell V Power. Put in Arco just to drive it a bit.

 

An update. I've not driven the car other than in-out of the garage so that I can try and diagnose the cause. Well last night it wouldn't start so hooked up the charger since the battery was reading 11.23V. After it charged up it turned over and I let it idle to run some fuel through the system. The slight miss fire was still present. I let it idle for about 5 minutes and thought that the PS air valve was passing PS fluid as it smelled a bit off but usual on cold starts. Looking at the tail pipe it was emitting white smoke and there was enough water condensation dripping out. It's semi cold but the white smoke was a bad sign. Pulled the dipstick and it looks like the beginnings of chocolate milk. Whatever has happened with the misfire has taken toll and reached this point.

Was hoping to get this to 300K but that looks unobtainable.

 

RA40,so sorry to hear about car.

Im still doing good as far as drive train at 255k.Just a strut lower bushing failure still not repaired yet(have KYB struts here),too many things that are priority,such is life.But all good here,very cool.

Oh,waaaaay OT...my next car is going to be an earlier 1.5 liter Yaris,most simple car ever made and being more limited as aging,that car is stupid simple to work on,helped neighbor on hers and damn Im impressed by that amazingly simple well engineered car.100k and purrs like a sewing machine,impressive!

 

Checking in.
The light colored oil is due to the injector staying open so all that fuel is not burning and is getting past the rings. Oil smells of gas which is better in some ways than a BHG scenario. OTOH that gas ruins the lubricating properties so concerned about getting that taken care of. Don't have the time nor $ at this point so the car sits waiting till that failed #1 injector can be dealt with.

Is it a difficult task to swap it out the injector/s on the driver side?

 

Maybe try some seafoam thru intake or equivalent treatment like Techron thru tank? Seafoam permanently fixed a sticky lifter in my Jeep

Good luck Mike,seafoam and techron used to get my Jetta thru smog when it threw P0302 and code would disappear,though it would return it did help.Dont miss that code throwing monster.

Im looking to add a first gen Scion xB to my fleet,same drivetrain 1.5 liter as a Yaris.So Im still looking for a good backup car.I Like the utility of xb.The LS is just such a big car but dang still running like a champ here,just so big.

 

I've run injector cleaner through it and for a short bit and that it worked. That misfire remains constant now so I'm hesitant to keep running it hoping it clears that particular injector. Unplugging the harness from it still flows fuel. Miss driving that car.

I like those xB's and Yaris. Good luck on the hunt.

 

i've handled many injectors but always as part of a job involving removal of the fuel rail. I would guess the rail needs to be moved to get the injector out. Might be able to bend it up or remove the bolt at the back of the intake to allow it to move more.

I have several junk yard injectors I could toss you if you want to go that route.

 

An update of sorts. It didn't run right so parked it till some time and $ could be devoted to this issue. Had it towed in the other day for diagnosis. The mechanic started it up and it was puking water out the tail pipe along with smoking. He said it had a BHG. Faint signs of water in the oil and the sheer amount of water that was coming out the tail pipes was obvious. I was baffled because it didn't overheat and I didn't drive it to aggravate the condition. It wasn't driven hard either, but oh well, it's done.

Disappointed that this came up in such a catastrophic way. The mechanic said he's had one other BHG for this generation. They are quite robust and the injector which I thought it was wasn't. Found a buyer who will put a long block into it for his project car. Too much $ for me to keep the old thing going. Will miss it.

No matter how I care for Toyota, getting well north of 200K has eluded me, this LS had 214K. Dad made 350K in his Corona and 325K in the Nissan. His Saturn SL2 that POS he got it to ~260K.

 

Real sorry to hear that Mike.We either wear out or age out.

 

I feel very sorry for your trouble.

I think it's a bit strange that only 200k miles was the time to have the BHG problem. Something must be wrong but who knows the reason. Anyway I hope you don't be discouraged.