Sudden Engine Surge

[DK]

Just under 100,000. Engine Check light came on. I was sitting at a stoplight when the engine took a very big surge. I had to stand on the break to keep from moving. I slipped into neutral. RPM's went way up for about a second then came down. I drove it today and no surge but I'd like to know what happened and what to do about it. Anybody?

Thanks

[VX KAT]

Can you get the CEL code read at a place like Autozone? They'll do it for free.

Many over the years have reported an irregular and often wildly flucuating idle, jumps up really high sometimes. It's often the mode selector switch.
Did you notice any of the gear selector lights flashing weirdly?

Although I don't recall any saying they had to stand on the brake - but thought it's worth a mention.

Here's a thread (one of MANY) that talks a little about it, and what others have done and cleaned to fix/attempt fix.
http://www.vehicross.info/forums/showthread.php?p=244366#post244366

http://www.vehicross.info/forums/showpost.php?p=110739&postcount=3

Do a search on "high idle" and maybe some other key words, maybe you can find a thread or other mention of your type problem.

I'm sure some others will jump in here to give you some more suggestions.

good luck. :thumbup:

[DK]

Thanks Kat. No wild flashing of lights. I'll get the code checked.

[VX KAT]

oh p.s - I worked at 26th/Colorado for about 10 yrs, know SM well…miss some of my fav restaurants there for sure now that I live in a town of 4,000 :laugho: , oh but we can go into "town" 8 miles away, THEY have 50,000 peeps! :laugho:

[DK]

If you've been away for a few years you might not recognize SM. The developers have take over and it's getting to be like NYC without the subways. But it's still the best part of L.A.

[Vendetta]

Look here (http://www.vehicross.info/forums/showthread.php?p=248880&highlight=idle+valve#post248880) also.

Good luck and report your progress/results.
-V

[tom4bren]

DK,

It sounds stupid but check your foot position on the brake pedal. It's real easy to get 'lazy foot' & just kinda pivot your foot on the heel when switching from gas to brake. I've gotten the surge before and noticed that my foot was on both pedals.

t4b

[evillecutter]

Throttle Position Sensor, Idle Control Valve, Fuel Pressure Regulator, Maybe Maf Sensor To Start With

[jasonm621]

I had almost the same thing happen & 105,000 miles. Rpm's went WAY up and had to stand on the brake approaching stop lights. No CEL though... It went away for about a week and was consistent high idle after that. Turns out the intake manifold gasket was badly cracked effecting all of the right bank cylinders! HUGE pain in the neck to replace but runs like a champ now 10,000 miles later! Since your CEL went on im assuming it may be some sensor, TPS maybe?

http://www.vehicross.info/gallery/data/500/DSC02469.JPG There is a service bulletin somewhere on a change in torque spec for the bolts on this gasket. Don't quote me but i think it changed from 16 ft/lbs to 13?