Idle and acceleration trouble after tension arm replacement

I replaced my tension pulley and arm last night due to pulley chatter. The pulley had noise in it when I spun it, but Toyota doesn’t service the part so I replaced the entire arm. On my 2011 that means removing the fan and shroud, battery, alternator, and ac compressor. Everything came out and went back in smoothly. All electrical was plugged back in (I double checked). Started it up and died instantly. Started it again…runs fine. Ok, now I step on the gas and it bucks. Drive to the first stop sign. Stop. Step on the gas, it bucks again. I can feel the engine trying to smooth out the idle, it’s speeding up and slowing down on its own. Next attempt at accelerating from a stop and the engine revs, but the truck doesn’t move for a second or two then lurches forward. None of these issues were happening before the repair. Any ideas?

 

Make sure you didn't pinch the crank sensor wire, it runs behind the A/C Compressor.

Do you have a CEL on? If so have you checked for codes?

 

My light was on for oil change. I did an oil change during the repair. I can’t seem to get the light off, so there may be a code. I don’t have a tester. Not really wanting to drive it this way. I was worried driving it would cause damage to other parts. I kinda play at auto repair. I’ve never had any formal training. I just use the repair manual.

 

Check Engine light doesn't come on for an oil change, it indicates a problem in the powertrain management system.

The Maint Reqd light is the oil change reminder, the reset procedure is in your owners manual.


If it's running as poorly as you say I wouldn't reccomend driving it.

 

Only light is maint req. I’ve reset it, but it’s still on. I’ll look at the crank sensor wire tomorrow. Someone suggested a damaged vacuum line. Thanks for the help.

 

Ok, the plug on the ac compressor was only half way connected.

 

Glad you found it!
Thanks for posting so others know where to look.

 

A retired fleet mechanic at the auto parts store told me to check for loose or damaged vacuum lines and loose or disconnected electrical plugs. He said the ac compressor was sending signals to the computer and the computer was confused so it didn’t know what signal to send the engine. It was weird, the engine didn’t remember how or when to accelerate. Kinda felt like a bad transmission problem. He said in the next 80 to 100 miles the computer will reset the timing on the engine and smooth everything out. I cannot believe a plug can cause that much trouble!