rough idle drives fine

[tht1guy]

hope im not repeating anybody but i have a idle issue. i have a 99 eclipse gst spyder all stock. recently had the timing belt water pump and tensioner done. of course this was by a shop. now it idles very rough and shakes the car. there is also a weird buzzing noise coming from the engine bay. these symptoms are only present when at a stop , other wise the car drives great shifts smooth and has no loss of power. i think the buzzing continues while drivimg but not sure... mechanic says that its the iac causing this issue whats everones thought? as it stands now we are waiting for the part just want to know what else we might want to look at.

 

[Sumopower87]

hope im not repeating anybody but i have a idle issue. i have a 99 eclipse gst spyder all stock. recently had the timing belt water pump and tensioner done. of course this was by a shop. now it idles very rough and shakes the car. there is also a weird buzzing noise coming from the engine bay. these symptoms are only present when at a stop , other wise the car drives great shifts smooth and has no loss of power. i think the buzzing continues while drivimg but not sure... mechanic says that its the iac causing this issue whats everones thought? as it stands now we are waiting for the part just want to know what else we might want to look at.

Well... Id say adjust the idle to see if that might help. Check all your intercooler piping. If you have a afr gauge and it's reading lean that might be a strong indication that the car has a leak somewhere.

Funny enough I'm actually experiencing the same issue but my car is an Evo 3 and has some extensive bit simple mods. Whereas your car is stock.

 

[tht1guy]

thanks will be checking into that as wrll then. we did adjust the idle to try and keep it from killing but the idle is still eratic. we will see what happens and good luck with your car.

 

[jimsgsx]

Take out the iac and clean it. Adjust biss.

 

[Lou98GSX]

i bet the balance shaft is out of time .

 

[Size9Zombie]

If it wasnt doin it b4 and its been doin it since u got it back, stands to reason and chances r, the timing or balance shaft belts r not properly installed, 1 tooth off on the timing belt may run fine driving but give it an erratic idle, have them pull it back down and double check balance shaft and timing belt alignment

 

[Silver gryffon]

Being off 1 tooth on the balance shaft seems to be a common issue with shops.

 

[Size9Zombie]

Its pretty easy to miss it by one tooth, ive been a tech for 15 yrs and have seen it quite a bit[DOUBLEPOST=1414442120][/DOUBLEPOST]With the engine idling have you got under the hood and tried to locate the source of the buzzing u were talking about?