Tune-Up Question

[leftyvette]

My 2000 coupe has developed a slight miss at idle and the gas mileage has dropped off a little. I think it is time for a tune-up. Here is my question: Which of the following would be best?

a. A tune-up by my local Chevy dealer.
b. Buy a handheld tuner and do it myself with the preloaded tunes.
c. Take it to a performance tuner and have it dyno-tuned.
d. Trade it in for one of those fancy 2010 Mustangs. (Just kidding)

 

[zagger]

Before any tuning weather dyno or even via a handheld you should get the car running properly. This applies especially if a hand held is your choice. There may be several reasons for a miss at idle, something like a dirty injector could cause it. I would recommend using a can of Techtron and a re-flash by a dealer along with new plugs. The only reason for tuning would be to improve performance and Dyno is the best, you can also get good results with a hand held such as the Predator but make sure it is the newest version as only the newest will allow logging and that is what you will have to do in order to really get the best from the tuner. This would be most beneficial if you have an automatic.

 

[c4c5specialist]

HI there,
What would be in your BEST interest, is to have the vehicle accurately diagnosed.
This means, have your PCM scanned and fuel trims looked at for any disparity.
GM tolerance is +/- 8%
If there is difference, then your next course is to have the injectors flowtested using the AFIT fuel injector tester.
This has the ability to tell you if there is anything wrong with the flow rates.
As was stated above, UPDATES to your PCM are always recommended, once the codes or any telling data has been checked and recorded.
After that, let us know what you have.
A dealership can provide printouts of all the tests I have suggested.
Allthebest, c4c5

 

[Hib Halverson]

As for the miss, an important piece of information--miles on the vehicle and how it gets used--was, uh...missing.

But, let's just assume, considering it's nine years old that it's got 40,000 miles on it. As long as the "service engine" light has not been on, I'd recommend you 1) inspect the condition of ignition parts (mainly plugs, wires and coils) and repair/replace as necessary then 2) run three bottles of Red Line Complete Fuel System Cleaner through the engine, one per tankful of gas for three fill-ups.

As for custom tuning, if the car is stock or near stock--you don't need it.

As for any PCM updates that apply to MY2000 and have not been done on your car--as "c4c5specialst" suggestes, you do need them.

 

[leftyvette]

Thanks for all the feedback so far. My car does have about 40,000 miles on it. I will check the plugs and wires and get the tests run that C4C5 suggested. I am at this time running Techron through it. I do not drive the car daily. I am fortunate enough to be able to walk to work. I drive the car on weekend trips. I do not drive the car hard. The miss and fuel mileage are not very bad, just noticeable. I changed the plug wires a while ago. I may not have gotten one of the plug wires on just right. I always have a hard time "feeling" if the plug wires are on for a good connection.

 

[WLS Ruby 93]

Lefty,

Another thing that you might try, which is inexpensive, is to clean the throttle plate and throttle body with a spray can of TB cleaner. If there is enough gunk on the plate it might not be closing all the way throwing off some the the air/fuel readings.
It couldn't hurt. Also, check for a loose spark plug and/or wire.

Keep 'em rollin'
Bill