rough idle, buzzing noise after water pump replacement

[myles42]

this weekend I replaced the water pump on my '96 TSI since it was going bad. I double checked to make sure all the timing marks were lined up before i put it back together and had my dad check it out as well. it starts up great but then it bogs down till it almost dies and then starts idling really rough like a cylinder isn't firing. checked the resistance on the spark plugs and wires, and used a timing light to make sure all the cylinders were firing. I did notice that there was a buzzing/arcing noise near the firewall by the intake/MAF. checked all the connectors i could easily reach and can't find anything loose.din't have any of these issues before replacing the water pump. Is there anything I can do/check to narrow it down before i just start replacing things?

 

[Develop247]

a rough idle could be caused by any of the following:
vacuum leaks, injector o ring damage,clogged air filter, fouled spark plugs, leaking egr...

 

[myles42]

well it turns out I made a mistake lining up the cams. when I checked with a straight edge I realized I lined them up about one tooth above center.

 

[jdub1992]

that will do it, I bought my TSI awd a smidge off, and i had to fix it, also just food for thought...

the 95 and 96 talon tsi and tsi awd and eclipse gst and gsx have the crankshaft and camshaft sensors near the timing belt. the camshaft is just inside the rear camshaft sprocket and the crankshaft is in the lower surrounding of the timing belt. It is beneficial to replace when doing the waterpump to replace both sensors, the timing belt if not fairly new and also to replace the valve cover gasket, i had to take mine off to get the sprocket off it was on so tight. but if they are in good shape than your good to go i just prefer prevention on my car.