PLEASE HELP! Bucking Problem

[mikey30]

Hey Guys so I just bought my first e30 two weeks ago and it's a 1988 325is. For the first week the car ran great and then one day began bucking and running real rough. The car will consistently run rough when the engine is cold and will continue to do so until the engine reaches normal operating temperature. At this point the car runs well. It idles well and only bucks while accelerating. I have replaced the fuel filter, coolant temp switch, and sensor. I also cleaned the air intake temperature sensor with a computer/electronics cleaner. I really appreciate any help I can get.

[Jeron]

I'd start simple by checking for vac leaks, intake leaks and check the plug wires.

[coolbear1]

Air intake first, look very close at the rubber elbow and the hoses that connect to it, Also see if your throttle body is clean.

If you don't find it there, your fuel pressure regulator could be bad, or the vac line that controls it, cracked or leaking. The fuel regulator will starve the injectors when you stab the accelerator if it is bad. The engine will stumble.

You can do a quick check by pulling off the vac line at about 2000 rpm. The engine should change rpm, if it is working at all.

I've got an 88 cabro, E30s are my favorite. They are tough as a tractor, if you take reasonable care of them..