Engine died going down the highway, why?

I started to slow down for a light from say, 55mph or so... pushed the clutch in and put it in nuteral. I had my foot on the brake and noticed the pedal push back real quick, then it required more force before the brakes would grab. Started to scare the crap out of me, but then I looked at the guages and noticed all the lights came on, and that the tach was dead. So I cranked it over and it started right back up... but the radio or anything didnt die when the engine shut off, kinda wierd.

IAC issues since the engine was returning to idle from when I put it in nuteral?

A/C wasnt on either. Its done it at low speeds before, usually pulling up to a light or stop sign. The RPM's will dance around from low to around 1100 or so untill it just dies, then itll start right back up. Only happened a few times like that though.



ADRENLN, too bad they didnt tell you what their "updates" were at the dealer. That way I could just go buy the parts... no way in hell id go to a stealership now though, haha.

Seems like quite a few people have this nagging little issue.

Little update... clean the entire TB and plenum today, along with the IAC. Car idles alot better, response is alot better, and it feels noticably smoother. No dips in idle or erratic bouncing of the tach yet. Should have seen the ***** that spewed out of the IAC...

McTeague said:

Burning Rubber, can you provide more detail on how you cleaned the TB and plenum? Did you remove them completely from the car to do this???

Click to expand...

Yeah... ill do a mini-writeup...

First off, get out the ratchet and assorted socket set and a flathead screwdriver. Those are really the only two tools needed. Buy a can of TB SAFE throttlebody/carb cleaner, it has to be TB safe for the sensors though.

Unscrew the air intake from the throttle body. I unplugged the air temp sensor and just layed it out of the way (I have a FIPK though). So either set aside, or remove intake.

Next up release the throttle cable, and return spring from the TB. Unbolt the bracket that mounts the throttle cable to the plenum, set aside. You should also totally unhook the return spring and set it aside.

Remove vaccum lines from plenum/tb. Remove the IAC line, the line in the back of the plenum, and the red line right next to the TPS. Make sure you remember where they go, or mark them down.

Unbolt the EGR (will take some force, be careful not to strike the plastic intake manifold with the socket... im sure enough force would break that peice of glass... ).

Now take off the 5 bolts holding the plenum on. Remove the plenum with the TB still attached. Once the plenum is removed, be very careful with the intake manifold gaping open... I would highly suggest laying a CLEAN rag across the opening of the intake manifold. Make sure its not dirty, and make sure nothing falls in.

Now that the TB and plenum are off, go ahead and pull the IAC off the plenum and set it aside. Seperate the throttle body from the plenum after that. All 4 gaskets (plenum to intake manifold, EGR, IAC, and TB) are reusable as long as you dont rip them.

After they are all seperated start cleaning them. Spray the IAC several times with the TB cleaner through both openings and watch brown liquid wash out. I wouldnt reccomend poking or prodding any of the openings on the IAC, just spray it out well.

To clean the TB, spray down the butterfly and wipe both sides. The rear part of the TB after the butterfly will probaly be the most dirty part. Wipe it out with the TB cleaner.

When your done with the TB start on the plenum. Mine was a solid crap brown color on the inside... just start spraying and wiping really hard with a rag untill it starts to look like metal again... Take your time and spray out all of the tubing that runs off of the plenum, make sure none are clogged.

Once all the parts are cleaned let them dry of TB cleaner, and re assemble the TB to the plenum, and the IAC to the plenum. Make sure the gaskets match where you mount them up, especially the IAC.

Once its back together, remove rag from the top of the manifold, make sure nothing drops in and reinstall the tb and plenum. Re-hook all the vaccum lines, temp sensor if unhooked, EGR, TPS and IAC sensors, throttle cable, return spring, and mounting bracket... reconnect the air intake and fire her up.

My car idled rough for a short time, even had a noticable miss in the exhaust note. If you want you can disconnect the battery before you pull and clean the plenum. This way it re-learns the idle and whatnot. Only reason I didnt is cause I didnt want to lose my sterio settings...