Engine "missing" under load

[tercel89]

My mom's 2002 RAV4 has a 2.0L 4 CYL in it . She has had it since new and it has been babied by me . All of a sudden today it started missing when the engine is under load . I put in new plugs and it still does this .It has one coil per CYL built into the spark-plug boot. . The check engine light indicates multiple misfires in cylinders 2 and 4 . I think the #2 and #4 coils are bad . What do you think ? Any help is appreciated .

I thought if I swap the 1 and 3 coils to 2 and 4 and then check the computer , it may show the 1 and 3 bad which would mean bad coils on those original coils . What do you think ? I need to get my mom back up and running .

[maroonandwhite]

I had the same kind of trouble out of my 2000 F150. I was getting the cylinders 2 and 4 or some type of error. Ended up just needing a good cleaning in some of the ports. I didn't have to buy any new parts but paid wayyyy to much for labor. I did try a new coil pack/ spark plugs/ wires at first but that wasn't the problem. You could take it to a dealer and pay $50 or so and get them to run a diagnostic on it which should be able to find the problem and then tackle it yourself to save some money.

[Guest db99wj]

I had a similiar problem in my old Jeep, with a 4.7L, it had the individual coil pack on each spark plug. It was a bad coil. Depending on the computer, it might clear it out or might not from what I understand. mine, once replaced, cleared out after a few restarts.

[Guest 6.8 AR]

You may be chasing symptoms. It could be as

little as an intermittent open on a fuel injector

wire, or could be a COP. Can you get it to Advance

Auto or Autozone? See what their code reader

shows. It could also be in timing, CPS or cam

sensor.

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[peejman]

Pull the plugs and check the condition. It'll be obvious if they're misfiring. Check the connection between the coil and plug and the wires to the coil itself.

[Guest TackleberryTom]

The Autozone code reader will not show anymore info than he already has.

Most likely failing coil packs. It is quite a common problem.

[Guest 6.8 AR]

Two at the same time seems odd, though. I thought it might point him in the right direction.

[Guest TackleberryTom]

Two at a time is not uncommon at all. Ford 4.6l have that happen often. Since they were all manufactured nearly the same time and have been used for the same amount of time it should be more likely than not.

It is hard to verify that one is bad unless it has stopped sparking entirely , which doesn't happen often. Their ability to produce a strong spark diminishes and you start to get misfiring under a load. They probably didn't "go bad" at the same time, it just became the most noticeable once two of them were malfunctioning.

[Guest uofmeet]

Go ahead and get new coils. It is either air, fuel or spark. And since it is only under load, and you swapped plugs, it is not air or fuel.....so change the coils and you should be good to go.

[tercel89]

You may be chasing symptoms. It could be as

little as an intermittent open on a fuel injector

wire, or could be a COP. Can you get it to Advance

Auto or Autozone? See what their code reader

shows. It could also be in timing, CPS or cam

sensor.

Sent from my iPhone using Tapatalk

Hey there Mr. 6.8 AR , Why didnt I go to you in the first place ! You doing ok ? Yeah , My computer shows misfires in 2 and 4 and so does Autozone and Advance Auto computers . Gonna swap out the 2 different coils and put them in the "working" cyl's and see if it shows misfires in 1 and 3 . If so Then I think I will have 2 bad coils .

[tercel89]

I swapped the coils to other cylinders and they are now showing misfires , so this makes me think the coils in 2 and 4 are bad .

[Guest 6.8 AR]

Doing fine, here. I think you got that one resolved. Those COPs are expensive on Fords. Hope they aren't

on Toyotas.

I had a peculiar one on my Continental that kept throwing a code:cylinder 5 misfire. It turned out to be an

injector connector that that the retaining clip broke off. The connector was falling back away from the injector

and causing a misfire. I tried replacing the COP until I stumbled on to the faulty connector. That's why I suggested

that. My ford mechanic friend said to move the injector to another cylinder, like you are moving the COPs around.

It's always something, isn't it?

You need to bring the cruiser back over here. I like to stir gossip up with the neighbors.

[ted]

what ever you do do not use the bosh platinum spark plugs that auto zone sells Thay will make them miss also DO NOT Use

[Jasongar8]

Yea it sounds like you need new coils. I have had to change 5-6 out over the years on my 5.4 F-150. I hope yours are easier to get to than mine are. The four on the back of the motor are a bitch to get to.

[Guest bdp07]

Most of the time you get a code that is telling you that you have a misfire on certain cylinder, it is a bad coil. Ford 5.4 and 4.6 coils are a very common part to go bad. I sell them everyday.

[Guest TackleberryTom]

6.8 AR, I have seen the fuel injector caused misfire before too. Usually with that it will have a misfire all the time. When it is only under a load it is usually a coil pack. I wish they would make the coil packs with the same durability as the old single HEI coils had.

What area of Clarksville are you in? I am down at exit 11 area.