Car dying over bumps/bad idle surge

[kbaszak]

I just got my water pump/radiator/timing belt and tensioner done at a shop and now there's some sort of fuel/ignition cut when I go over bumps and sometimes it dies and has a random idle surge. Anyone have any ideas?

edit: brought it to the shop that worked on it and now it backfired and won't start

[jlevie]

What car?

There could be more than one problem here. The idle surge sounds like intake leaks or an aged O2 sensor, but there are several other possibilities. The cutout when encountering bumps sounds electrical.

[E30NJ]

that backfire doesn't sound good. you could have blown out some valves....

[kbaszak]

It ended up being a bad crank sensor that only happened when it got hot. I'm pretty new to these cars and honestly haven't done much work on them but I'm guessing its either on the front of the engine near where he worked or in the bellhousing. Its an 87 325is so would it be something that they couldve messed up?

[jlevie]

Your 325is has the crank position sensor mounted on the right front of the engine.