Changed spark plugs and now getting misfires

...me neither, so thanks!

 

Me neither, good thing somebody went to the trouble to look it up! Most folks just move on and deem the post unreadable if they get too lost.

 

I thought it might have been a typo for "cap" (my phone/tablet) is always mis-guessing words, stupid bloody thing!!!

 

You did no such thing. After thinking about the context for a few seconds it came to me.
But a REALLY LOT of people who come here would have no clue.......as evidenced by the 3 prior comments.

(Mentally reviewing several closing comments about people who act like this.......and I will just stop.)

 

Pretty soon this thread will sound like a Twitter feed!

Basically, just try to be considerate and communicate at the level of you're audience,
Second, don't insult them when they don't understand lingo that's not in their normal vocabulary ...

That always shows a bad light on the teacher, not the student.

No one is stupid out here! "that's when this all hit the fan!" Every person was insulted!

Just some are asking questions about an unfamiliar subject while others answer = the reason we have tech forums in the first place.

I'm sorry if my humor wasn't appreciated... Some hate my avatar as well bc it's not serious
Not apologizing... Just sorry

 

Nearly all 2 valve Ford Modular V-8s from like '1997, the 1NZ Toyota and countless more. Boot failures are more common the COP failures and/if left unaddressed, it can lead to COP failure.

Both AutoZone and Rock Auto sell them for the Gen2, it is as common a tune-up requirement as changing the wires on an engine with them.

 

On both my old Gen 1 and my current Gen 3, the boots on the OEM ignitors can be popped right off. I did that to clean and inspect them. I just don't think they're available from Toyota as a separate part.

I didn't know they were available elsewhere either, though at one point I entertained the notion of getting a cheap set of no-name ignitors, just to see if their boots would fit on my OEM ones.

-Chap

 

SO....how did you solved the problem ? Did i missed that part ? I have a Prius Plus, the car was perfect (200.000km) but the dealer recommended to change the sparks.
They made the change, but since then my engine is not working perfeclty. It has small almost imperceptible shakes.
I put it on tester and have random misfire on random sparks.
What can i do ?

 

I have a set of brand new coil on plug s for a g2 part number 90919-02240.
There is a rubber piece on the bottom of the cop the part that surrounds the plug is rubber and I tried to remove it but it’s really on there. I don’t think you can pull that boot off without possibly damaging the spring.
But maybe I’m just afraid of ruining my new cop.
I’ll check amazon cause I just bought a set of replacement denso boots and springs off there for my Crown Vic. Worked perfect.

 

Boots only are not available on amazon. But you can buy a set of aftermarket cops for $50.
I would get a set of cops. Oem cops online are $80 each.

I bought a set and I will change the plugs and install new cops and be good for another 100000
Miles. I hate misfires.

 

No way in H#LL I'm spending $360 for COPs when all I need is four boots for $50

Just because Amazon does not sell something, does not mean it's irrelevant or not available. After all, my wife's new RAV-4 Hybrid cannot be had there

 

When I change spark plugs in a engine with Coil On Plug (cop) I clean the bottom boot on the cop and the rubber seal at the top.
When I put the new spark plug in the hole I use a short piece of rubber hose that fits the top of the plug to insert the plug and start it in the hole. This reduces the chance of cross threading and also banging the electrode against the engine. I would not recommend starting a spark plug with the socket and extension as shown in the video.

John kb0ou

 

I just want to add that I just set out to replace spark plugs after just buying a Prius last week . I went with Denso SK16R-11 upon Priuschat reviews. However, OEM is part# 9091901275 which is Denso #K20HR-U11 (for 2008). I was experiencing misfire problem after installation as well. I decided to just go and buy the old ones that I pulled out which were the NGK Iridium BKR5EIX-11. Long story short the Denso SK16R-11 did not work while the NGK Iridium BKR5EIX-11 plugs are working well. I gapped the Densos multiple times to spec .0393-.0433 And they just simply would not fire.

Spark plug gapping tutorial:

Don't worry gapping tool is $2 and spark plugs don't have to be too tight.

Note: When I pulled the NGKs out they were spaced at about .047 so when I replaced them I spaced the new ones to .047 as well. Let me know what you guys think.

 

The spec is 1.0 to 1.1 mm. That translates to .039" - .043". I set plug gap to 1.0 mm.

.047" is like the gap of a worn out plug.

I don't know why you had difficulty with Denso SK16R11, that is the model I use. However NGK also is an original equipment supplier to Toyota. IFR5T11 would be the NGK model closest to the original equipment plug.

NGK Spark Plugs

I would say the NGK plugs with iridium tip and platinum on the ground electrode will have a longer service life compared to Iridium IX which lacks the platinum on the ground electrode.

 

Banging the plugs in the well? That's excalty what was in my mind too. If those plugs were dropped in there without caution, the gaps changes from the spec.

 

If you still having the misfires, remove the new ones and reintroduce the old ones and see what happens. If the misfires stops, then you may have mistakenly dropped the plugs so hard in the well.

Ensure you regauge the new plugs to see if they still remain as they were(the gaps, I mean).

 

Two things about that:
Why would you think it is OK to "set" them outside of spec. ??
And Iridium plugs are NOT supposed to be messed with when installed; they are gapped at the factory.

They likely were at .047 because of use and wear.