We got my son a 1995 Jetta III with the 2.0l engine. The price was right (USD 1500 under book value), and we knew going in that it was a bit of a project car. A timing belt, water pump, injector seals, one new injector, shocks, front brakes and rotors, partial exhaust system, shift linkage "adjustments," new instrument lights, and assorted nits and lice later, it's pretty close to roadworthy.
There's one significant problem left. Sometimes (but often), it bucks under acceleration. Sometimes it does not. The weather and temperature have no effect; it can be rainy or dry, cold or warm. Cleaning the coil ground wire helped reduce the frequency significantly. The coil wire resistance is OK, cap and rotor are new, and no sparks show in the dark. No check engine light or new codes (since the injector and seals were replaced, that is).
Any ideas? The coil is about USD 100. I don't mind replacing it if it's a common Jetta problem, but after the foregoing repairs I'm reluctant to shell out for it without a bit more evidence...diagnostic information very welcome!
Also...any other common problems to watch or check for?
Thanks.
JRE