Throttle Body instead of Bad Head?

[Hayden]

Hey everybody,

I've been having problems with misfires for a while now and ive been trying to figure out what the culprit is. I have an 06 which means im in the range for having a bad head, but i dont think it is the head because i only get the misfires when the 3 is idling and they arent specific to a certain cylinder. This leads me to believe that its caused by the throttle body (specifically the idle air control valve inside).

Ive cleaned the maf sensor and throttle body twice now

Any thoughts would be appreciated im just hoping and praying its not the head :sigh:

 

[SolidusJ]

Same thing happen to me when I ran E3 spake plugs, burned out my #2 Ignition Coil so I would say try that out also.

 

[Hayden]

running almost brand new acdelco plugs, coil packs are next though

 

[digglesworth]

Get a code reader on it. Even though the CEL isn't on, it may be throwing codes. That can narrow down which cylinder is causing the misfire.

 

[Mr_Rich]

Having had to replace my throttle body recently I can tell you that all that is affected is drivability along with reduced power and codes of that sort. If there aren't any latent codes (which is probably the case) then a code reader doesn't help you. When I got to reading my factory manual it pretty much said a code 2135 means bad TPS and a new throttle body. If you don't have a code there is nothing to chase there. That's the pain about intermittent type failures.
My GF is having similar misfire failures with her Nissan. I've replaced two coil packs and the codes still come back intermittently. I would chase a problem in a distributor IF they had one. Misfires make me think maybe it could be a crank or cam position sensor "upstream" ...possibly????

 

[digglesworth]

I had a misfire in my 06 also. Did the usual cleaning of the MAF and TB. I changed a coil pack that was full of corrosion. I thought that would surely be it. But it wasn't. So I took it to the dealer and paid $110 for them to diagnose it. The tech was done in 10 minutes. He hooked a code reader up and pulled up a xx302 code ( I can't exactly remember the exact code ) but 302 is a misfire in cylinder 2. (300: general misfire, 301: cyl 1, 302: cyl 2, etc...). He took the coil pack from cyl 2 and swapped it with cyl 4 and ran it again. Pulled up a xx304 code that time. The trouble followed that coil pack so we knew that was the problem. They wanted $225 for the coil pack. I said no. I went to advanced auto (where I got the coil pack the day before) and bought another one for $70. Put it in and left my battery disconnected for about 30min. Started up and ran good again.

This was my experience with my misfire problem. Yours may or may not be a similar issue. But I thought that's how these forums work... You post an issue and people throw out ideas or experiences as to give you some ideas on what to check. If Mr.Rich says a code reader won't help, he mustve had a different experience. You have to start small and work your way to the bigger things. You wouldn't want to have the head replaced and come to find out it was a bad coil pack. It seems like you're on the right track. Cleaning the maf and tb. Good spark plugs... Etc. If you don't have a code reader, swing into AutoZone and get them to hook up theirs. It's free and shouldn't take any time at all. I'd have saved myself $110 if I'd of went by AutoZone instead of taking it to the dealer. But that's what happened. That's how I got my misfire fixed. I'm not saying your having the same exact issue but it certainly won't hurt or cost anything to hook up a code reader and see. At least that way you can start crossing things off the list and keep working your way down the line.

 

[digglesworth]

Oh and when I first got to the dealer and explained what I did in my troubleshooting, he thought the throttle body might have to be "reset"... I don't know how or what that involves but apparently the TB can get out of sync. I've read about that before but can't fully explain it. He suggested it may be that because I removed my TB to clean it. Something about the position of the flap or something. That gets outta whack. He said it's a quick fix and sounded like all they had to do was reset it...

 

[DaWgPoUnD]

Gaps set correctly on the plugs? if yes then proceed to changing the coil packs...I chased a similar problem and ended up changing ALL the packs in the process and issued solved.

 

[Hayden]

Get a code reader on it. Even though the CEL isn't on, it may be throwing codes. That can narrow down which cylinder is causing the misfire.

got a read and advance auto, its throwing random codes

Having had to replace my throttle body recently I can tell you that all that is affected is drivability along with reduced power and codes of that sort. If there aren't any latent codes (which is probably the case) then a code reader doesn't help you. When I got to reading my factory manual it pretty much said a code 2135 means bad TPS and a new throttle body. If you don't have a code there is nothing to chase there. That's the pain about intermittent type failures.
My GF is having similar misfire failures with her Nissan. I've replaced two coil packs and the codes still come back intermittently. I would chase a problem in a distributor IF they had one. Misfires make me think maybe it could be a crank or cam position sensor "upstream" ...possibly????

yeah im leaning more towards coil packs now, thanks!

I had a misfire in my 06 also. Did the usual cleaning of the MAF and TB. I changed a coil pack that was full of corrosion. I thought that would surely be it. But it wasn't. So I took it to the dealer and paid $110 for them to diagnose it. The tech was done in 10 minutes. He hooked a code reader up and pulled up a xx302 code ( I can't exactly remember the exact code ) but 302 is a misfire in cylinder 2. (300: general misfire, 301: cyl 1, 302: cyl 2, etc...). He took the coil pack from cyl 2 and swapped it with cyl 4 and ran it again. Pulled up a xx304 code that time. The trouble followed that coil pack so we knew that was the problem. They wanted $225 for the coil pack. I said no. I went to advanced auto (where I got the coil pack the day before) and bought another one for $70. Put it in and left my battery disconnected for about 30min. Started up and ran good again.

This was my experience with my misfire problem. Yours may or may not be a similar issue. But I thought that's how these forums work... You post an issue and people throw out ideas or experiences as to give you some ideas on what to check. If Mr.Rich says a code reader won't help, he mustve had a different experience. You have to start small and work your way to the bigger things. You wouldn't want to have the head replaced and come to find out it was a bad coil pack. It seems like you're on the right track. Cleaning the maf and tb. Good spark plugs... Etc. If you don't have a code reader, swing into AutoZone and get them to hook up theirs. It's free and shouldn't take any time at all. I'd have saved myself $110 if I'd of went by AutoZone instead of taking it to the dealer. But that's what happened. That's how I got my misfire fixed. I'm not saying your having the same exact issue but it certainly won't hurt or cost anything to hook up a code reader and see. At least that way you can start crossing things off the list and keep working your way down the line.

Thanks for sharing! its nice to know im not the only one

Oh and when I first got to the dealer and explained what I did in my troubleshooting, he thought the throttle body might have to be "reset"... I don't know how or what that involves but apparently the TB can get out of sync. I've read about that before but can't fully explain it. He suggested it may be that because I removed my TB to clean it. Something about the position of the flap or something. That gets outta whack. He said it's a quick fix and sounded like all they had to do was reset it...

i removed mine also :whaa:

Gaps set correctly on the plugs? if yes then proceed to changing the coil packs...I chased a similar problem and ended up changing ALL the packs in the process and issued solved.

Yeah i had to set the gap it was running like oop:

 

[Mr_Rich]

Oh and when I first got to the dealer and explained what I did in my troubleshooting, he thought the throttle body might have to be "reset"... I don't know how or what that involves but apparently the TB can get out of sync. I've read about that before but can't fully explain it. He suggested it may be that because I removed my TB to clean it. Something about the position of the flap or something. That gets outta whack. He said it's a quick fix and sounded like all they had to do was reset it...

I'll elaborate on the "reset" of the throttle body. When I was getting the code 2135 it pretty much stopped the truck. When I connected the code reader with the key on/ engine off and pressed the accelerator there was no butterfly action on the throttle body. Once the code was cleared I was able to press the accelerator and see the butterfly move via the TPS data on the code reader. This action did NOT fix the throttle body. It was still a failing component ticking like a time bomb waiting to fail again and it did a number of times during each refill of a tank of gas.
My seat-of-the-pants feeling was that the old throttle body wasn't reacting as quickly as the new one and it felt like it was stumbling more on start-ups. Once I installed the new throttle body the truck seemed to drive much better.
On any of my OBDI, or OBDII vehicles when the code is cleared or clears by itself the ECM doesn't store the history. The only info available are the miles when the last time any DTC was cleared.