I picked up a 97 4 door civic. It has a 1.6 non vtec engine. Auto , most all options. Now to the problem. It sat for 1 year and had a bad battery and a siezed alternator. I put a charger on the battery, cut the belt and it started up ok. I drove it on the trailer and took it to my local shop to have it repaired. I just don't have the time to do all my repairs now. Ok, so it ran good on the trailer until the battery went dead and no electrical was left in the car. So we pushed it off the trailer and left the shop. The tech called me when it was done to pick it up. He replaced the alt, belt, battery, did a oil change and a coolant service. When I picked it up the idle is surging up and down 1000rpm to 2000 rpm. Every 3 seconds or so. He said the computer needs to re-learn the idle curves...BS! I used to be an auto tech back in the early 80's and I need more of an explanation than this. The car starts fine and will idle at app 1500 rpm when first started, then about 1 minute after start up it starts to surge. If I put it in gear it will smooth out but at a idle speed of app 1500 rpm. Which is too fast so the car will start going if I let my foot off the brake. Any help would be great.
Thanks, Bruce

 

First off, I would suggest removing the gas from the tank if it is still the one that was in there last year. Gas degrades and goes bad with time. 1 Year of sitting around will do this and cause all kinds of problems. Once you have a good tank of gas and you are sure the bad one is out of the lines I would change the fuel filter. Then I would check the plugs. All the usual tune up stuff. The last few things I would look at are the idle control valve, fuel injectors, and the MAF sensor. Any of those could have gone bad just sitting there. The computer does relearn the air fuel mixture(fuel trims) and while I have seen surges of a few hundred rpm before when they are way off, you first have to have everything working correctly before it can do its job right. I hope this helps.