Please Help

Hello All, My Lumina Just Started To Get A Shimmy (vibrating/shaking) While Im Sitting At A Light Or Even In Park. It Never Did This Before. The Performance Seems To Be Fine, But The Shaking Is Nerve Wrecking. It Has Never Done This Before. 93 Euro 3.1 V6 129000 Miles, New Coil Packs, Map Sensor, Tune Up Last Summer, Oil Change Every 3000 Miles Faithfully. New Alt. 2rs Ago. Just Trying To Eliminate Some Things, But I Dont Know What Else To Look For. Please Help. Also Cleaned The Intake Throttle Body Recently.

Were the plug wires replaced when you replaced the coil packs? That's my first suspicion. If all of the ignition components are fairly new, ie: coil packs, plugs, wires then I'd start running diagnostics on your injectors. First rule of "shade tree" mechanics is to check the cheapest, easiest possible causes first. That would be your plug wires. If plug wires are not the culprit, then my 2nd suspicion would be improper fuel flow either to, or through the injectors. You could have something as simple as an injector that is getting a bit gummed up. If it's beginning to get clogged, the first place you're going to notice improper fuel delivery is at idle, under load. (at a stop light in gear).

Could be something as simple as running a good injector cleaner through the system. However, please get some good, competent advice on which type you can use with your engine. Not everything on the market is beneficial to injectors, no matter WHAT the label on the can says. I'm awfully hesitant to put anything in the fuel system without checking it out thoroughly first.

Hope this helps.

Thnak You For Your Reply, The Wires Were Replaced Roughly 3 Months Before The Coil Packs Were Replaced. However I Have Been Thinking Of Upgrading To Performance Type Wires. Does Any Know Of A Good Feul Injector Cleaner??? I Have Heard That The Lucas Brand Is Good, I Have Only Used It In My Car Oil However. Thank You Once Again

You could see if you can find the 3M injector flush that shops use. It's a big pressurized can that you run to the service port on the fuel rail, disable the fuel pump and pressure regulator and let it run until the can is depleted.

Scrubs injectors real nice. You may be able to rent the adapters if needed from a parts store. I can't remember if the can will attach directly on your car.

Thanks, Know You Have To Excuse Me. Im Still Learning About Cars, Where Exactly Is The Service Port For The Fuel Rail, And How Do I Disable The Fuel Pump And The Fuel Regulator?

Also If I Do So Happen To Come Accross This Product Is There A Chance Of It Damagining The Injectors Or Anything Else?

The service port on a fuel rail looks almost like a tire valve stem, only its on your fuel rail. (the rail is the thing thats under the plenum on the 3.1's that all the injectors are attached to) you should be able to get to the service port without removing the plenum though. To disable the fuel pump, simply pull the fuse labled fuel pump, and then try to start the car to make sure the pump is disabled. And in a word, No, this method of injector cleaning is very safe, probably the best because its recommended by GM itself. I maybe would just look for some new injectors, if they have never been replaced, thats more than likely your problem. They could be either sticking open and leaking, or sticking closed. Try to clean them, and then replace. Good luck

How Hard Is It To Replace The Injectors. All Of The Other Work Mentioned I Did My Self. Injectors Im New To! Thank You All So Very Much For The Help

on the 3.1's its a matter of pulling the plenum off, and then you may have to pry on the rail a bit to get it free, all the injectors should come with the rail. Then its just a matter of unplugging them and plugging new ones on. Keep in mind you need to buy new o-rings for the new injectors also. once you have them all swapped out, you may need to lubricate the o-rings with something to get them to go back in, I've heard of guys using vaseline. Never used it before myself, but I suppose it works. Its a fairly decent job on the 3.1's because the plenum has to come off first, but it can be done. You may need to buy a new plenum gasket also. If anyone has anything else to add, please do. Good luck

thank you very much. i found out what the problem was. the service engine light finally came on, so i took it to my local murrays parts store. they pulled two codes 1 for the o2 sensor and another for the idle control valve. the o2 sensor is new, so i figured the idle cotrol valve was actually bad and it was also causing a code for the o2 sensor. so far so good!!!! i will look into replacing the injectors. im really into keeping my car in decent shape. i guess ive been doing a pretty decent job, especially since i dont know a whole lot about cars. ive pretty much learned everything i know on my own. i will be doing my rear brakes this evening, wish me luck. oh a quick question, if i get performance wire will that actually make a difference in my performance.

you should try at all cost to avoid using vaseline or any other petroleum based lubricant. tends to break down the rubber compound faster, especially where there is lots of heat. i've found that a silicone lube works best.

good to know