Changed Spark Plugs and Now Car Won't Start

[VegeLasagna]

BACKGROUND:

So I have a 2009 Yaris with 59,000 miles on it. Haven't done any real maintenance on it other than scheduled oil changes every 5000 or 10,000 miles.

For awhile, I noticed my battery is getting weak, about a year now, mainly when I'm charging my phone with engine off for awhile, and start the car, it cranks slow, but still starts. It hasn't done this in a few months though, but the last two weeks, I've noticed my car, when driving would drive slightly weak... like won't accelerate as fast or slightly struggle trying to get past 70 mph. It's nothing major and will only be noticeable to ME, since I know how my car drives.

The last weak, I noticed the MAINTENCE REQUIRED light go off on my car, only when I start my car and disappear right afterwards. I was thinking maybe it was because I'm about 600 miles away from my scheduled oil service change, since that's what usually what happens when I'm about 500 miles away from my scheduled oil change service.


PROBLEM:

Anyways, my dad changed the spark plugs today. Got NGK plugs. After changing them, car wouldn't start. Would barely get a spark. When trying to start car, it wouldn't crank and a screeching sound would come on. He tried putting back the old spark plugs back in and still same thing.

After a few hours trying to figure out what was wrong, I figured it was the battery, he said he checked battery and it was still good, but i haven't changed battery since 2009. So we tried jump starting the battery with another car and the engine FINALLY CRANKED... but wouldn't start still.

We've checked the gap of spark plugs and its fine.

Is it just the battery that's the problem? Wouldn't jumping the battery allow it to start?

The car was fine before the spark plug change (other than the weak battery and slightly low feeling driving power)

I don't know anything about cars, but my dad does, and he's stumped.

Thanks.

[CTScott]

Did you try putting the old plugs back in?

[VegeLasagna]

Did you try putting the old plugs back in?

Ya, we put the old plugs back in.

So, we got the car to start.

BUT... now the car shakes and during idle, the engine shakes. Check engine light came on too.

Tried to drive it, but once we put the car in Reverse, the car shook like crazy. Definitely not sure what the problem is.

[CTScott]

Clean the throttle body. If you disconnected the battery you may be having issues with the carbon deposits in the throttle body affecting the calibration of the butterfly (which occurs when you reconnect the battery). If it runs fine after that, then you got a bad set of new plugs.

[VegeLasagna]

Clean the throttle body. If you disconnected the battery you may be having issues with the carbon deposits in the throttle body affecting the calibration of the butterfly (which occurs when you reconnect the battery). If it runs fine after that, then you got a bad set of new plugs.


We never disconnected the battery. But I'll try cleaning the throttle body. Won't be able to get to it til tomorrow since I have to go to work now. Thanks for the help. Appreciate it.

Ugh, should have just taken it to the shop. Just changed the spark plugs and now all hell breaks loose lol.

[LTHatch]

Did you put the coil plugs(the wires connecting to the coils) back in the right order?

[Exiwolfman]

Clean the throttle body. If you disconnected the battery you may be having issues with the carbon deposits in the throttle body affecting the calibration of the butterfly (which occurs when you reconnect the battery). If it runs fine after that, then you got a bad set of new plugs.

this sounds right and usually the problem described, its by wire so key forward and have second person open throttle body by pushing on pedal than clean it .

[CTScott]

Did you put the coil plugs(the wires connecting to the coils) back in the right order?

This is one that could definitely cause big issues, but with the way the harness lays it would be difficult to do so.

[VegeLasagna]

This is one that could definitely cause big issues, but with the way the harness lays it would be difficult to do so.

Is there a surefire way to tell that it's in the right order. I asked my dad and he said he put it back in the right order

[Exiwolfman]

Is there a surefire way to tell that it's in the right order. I asked my dad and he said he put it back in the right order
I find it hard to believe u mixed it up its not like old wires, I still say throttle body needs a good clean, like when u replaced a battery on a high km car on flyby wire this happens 90% of the time.

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[VegeLasagna]

I find it hard to believe u mixed it up its not like old wires, I still say throttle body needs a good clean, like when u replaced a battery on a high km car on flyby wire this happens 90% of the time.

Sent from my Nexus 5X using Tapatalk

K I'll try that thanks. The car is shaking like crazy and when pressing down on gas, it shakes even more and makes a not so good sound kind of like the muffler is loud.

[VegeLasagna]

So I just finished cleaning the throttle body.

It didn't work. Still the same thing.

The exhaust in the back is pumping.
And I took a pic of the spark plugs (the new ones that we put in) and they're black now.

[CTScott]

So I just finished cleaning the throttle body.

It didn't work. Still the same thing.

The exhaust in the back is pumping.
And I took a pic of the spark plugs (the new ones that we put in) and they're black now.

Do you have any modifications to the car, as those are crazy fouled?

[VegeLasagna]

Do you have any modifications to the car, as those are crazy fouled?

No. Only mod is headlights.

[CTScott]

No. Only mod is headlights.

Truly a strange issue. Did you per chance fill up with gas just before you replaced the plugs?

[jack black]

And I took a pic of the spark plugs (the new ones that we put in) and they're black now.

they wont work in this state (and probably never). clearly the engine runs only on 1-2 cylinders. did you somehow damage the coils during installation? are the plugs properly screwed in and properly torqued? what is the condition of the old plugs now?

[CoryM]

Post a picture of the way you have the coils installed. It sure sounds like you mixed up two coil connectors, though I am not sure it possible on these cars. Are all 4 spark plugs black or just some of them?

[LTHatch]

Mixing the connectors up is easy to do, especially cyl 3&4. To paint my valve cover i removed it, every symptom hes having now is what i had(flashing check engine, engine barely idling, shaking, exhaust sounded like crap). Its a easy mistake to make if you're a new fella or didn't take a picture of everything before disassembly.

[NJP440]

I changed my spark plugs on my 2010 yaris got a kinda similar issue turned out to be bad coil pack

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[CoryM]

Yes, it's most likely a misfire due to "installer error". Probably mixed up coil connectors, or a broken coil. Not a big deal. Step one is to confirm the connectors are correct, then we can diagnose from there.

BTW, the black soot on the plugs is likely from the engine seeing too much unburned oxygen in the exhaust, thinking it is lean because of it, and then dumping lots of fuel in to compensate.

Cheers.

[SirDigby]

I can't believe no one asked, WHAT ARE THE FAULT CODES?
this sounds like a misfire. the engine codes will tell the issue....