Hello all - I had an account on here a few years ago but was deployed for some time and I believe the forum deleted my account :frown. Okay now to the problem...
BLUF: My FJ has a very rough idle, either in park or drive, but when stopped.
Backstory: I replaced my plugs with Denso Iridium's. I went through each one very carefully. Additionally I just installed a AIRAID CAI. I thoroughly cleaned the MAF, etc. I also unplugged the battery upon installation. This is really puzzling me because I am pretty good when it comes to mechanical work, but I have gone through everything at least three times and still no luck. Also, for some reason the vehicle seems to be running lean....
So directly after replacing the plugs it runs badly? I think its the plugs. I've read a few reports of the fancier plugs causing issues in the pre 2010 FJC's. That's why I replaced mine with the regular Denso's. What year is your FJ?
I replaced the plugs in my 07 with Iridiums with no issues... You can mess up the tip on an Iridium if you don't use the right type of tool for gapping, etc.
If you have problems after you worked on it and you've triple checked the things you did start looking for something where you were working(knocked of vacuum hose, loose or disconnected sensor connector, etc...). By the way do you have a check engine light on?
I looked over all of the hoses; I'm going to disconnect all of the connectors to the coils and make sure they're snug. I do not have a check engine light on either. I checked the OBD II to double check if it was throwing any preliminary codes but it came up negative...
I put fancy iridium plugs in my 07 and it ran like crap. I put stock plugs back in and it ran fine. Also did you happen to make sure all your plug wires are plugged back into the coil packs? ( Listen for the click ) I left one off my wifes corolla and it idled like hell. I found the wire and plugged it all the way back in and it idled smoothly Hope this helps
I think it's the military in me putting the BLUF hahaha. I appreciate all of your responses. I'll be running through everything tonight to find out what's going on. More to follow tomorrow.
Update status: I went and purchased the OEM DENSO copper plugs; set the gap at exactly 0.043 (as per the owner's manual). Cranked the engine and after a few tries she started up. Smoothest idle since I purchased the FJ from the factor. The acceleration is back! Thank you all again. Next install this week/weekend will be a new exhaust system...
I am at 52K in my 2008 now, and I am sure the plugs have not been changed. Just ordered 6 of the Denso K20HR-U11's, looking forward to putting these in this weekend.
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