idle problem

i went to the mechanic, he installed two chips into my ecu, they both did not work as they were the wrong chips. so we install the stocl chip back in. now my idle is real high at 1100 rpms, and sometimes it dips down real low, almost turns off, than shoots back up to 1100. i unplugged the negative terminal from the battery for 20 mins to reset ecu, but i still have the cel and the rough idle. also i dont know if this is connected, but my ac won't blow cold air. the fan turns on, but there is no cold air. replys are appreciated
thanks

what kind of car, engine?

sounds like the ecm is shot

1997 jetta. 79k miles. what makes you think the ecu is shot? the car runs flawlessly except the idle, and i heard that it will smoothen out. my ac has me stumped. im taking it back to the idiot mechanic on wedneday. 2 liter engine

help!

any advice?

apparently not. and making posts in your own thread to get attention is a bit lame

i got these codes from autozone. can anyone shed somelight on them?
whats your problem casey? im just trying to solve my problem isnt that what forums are for?

p1452
maufacurer contrl
auxillary emmission
controls

p1420
manufacurer contrl
auxilary emission
controls

p0303
cylunder 3
misfire detected

p1580
manf cntrl veh. spd.
idle speed control
auxillary inputs.

looks like the guy put in the wrong chip. do you have a california emissions vehicle?

no it is the correct chip, i just went out and checked. no sir, i do not have a california emissions model.
the misfire was from when the wrong chip was put in, theres no misfire now. What is auxillary emission?

the 1420 and 1450 are secondary air stuff, check the fuse for it next to the coolant resivour and next to the battery ( on a clear plastic case thing)

can you be a little more specific please? i know of one fuse in the clear plastic box, its one fuse, but there are two slots, only one of them has a fuse in it. there has always been one fuse there since i brought the car.I don't see a fuse next to the coolant reservoir, but it is midnight here, and i will take a better look tomorrow morning. if i can, what i will do is take some pictures, and you can tell me if im looking in the right direction. Thanks veeD, your help is appreciated

ok, i understand what you meant now. the fuse is good.

if you have a vacuum pump, pull the vacuum line off the secondayr air combi valve (on exhaust looks like a circle thing with large plastic pipe coming off) check if it holds vacuum ( it should)

i dont even know if a 97 has secondary air.. maybe the guy that put the chip in got one for a vehicle with secondary air and your car doesnt have it, vice versa. secondary air pump and system only operates on cold startups (may explain why runs rough till its warmed up

It idles rough when its warmed up AND when its cold. i dont think i have the secondary air pump, but do you know how many miles it takes till the ecu relearns itself? the mechanic did something when he installed the chip though, he cut off the engine from the engine bay, maybe when he was doing that he unplugged something? I read somewhere that if something happens to the ecu, the computer will shut off the AC fan clutch as a fail safe, and elevate the idle to the factory mandated 1100. this sounds alot like my problem, do you think this is what could be happening?

also, do you know the fuse for the AC? that would be of great help

from the codes you have seems like the guy installed a chip for a vehicle with secondary air and your car doesnt have it. aka.. ecm is looking for solenoids and parts the car doesnt have and then sets codes for them (open circuit)

well i have the stock chip in there right now, because the car was only running on 3 cyls. with the aftermarket chip. i just dont understand why the rpms dip real low, i can understand the high idle because maybe the ecu is trying to find the correct settings. do you know how long it takes for an ecm to re-learn is preoper settings? lol, it would suck if i engaged the clutch at about 90 mph, and the rpms dip low and the car shuts off

you know what else? if i stall the car, it won't turn on, unless i tap the accelerator like crazy

if the car runs better with the stock chip than the aftermarket chip is either wrong or bad.

try slowly depressing the gas all the way to the floor and holding it for 5sec with the car off key on that sould adapt the throttle body

so.. this seems a little too easy. just put it in the 'on position' depress the accelerator slowly keep it there for 5 seconds, than let go of the accelerator and turn on the car? or leave the accelerator floored than start the car?

didnt work. fo you know the fuse for the AC?