’87 325is with some strange fuel and vibration issues?? (I think)

[mms16]

Hi-
I have an ’87 325is (5-spd) with some strange issues. I have only had it fro about 5 months.

First off it does not idle smoothly. The engine will run smoothly, but intermittently it will shudder, and then stop, and then shudder etc. This always happens, and it is in approximately 3 second intervals, sometimes longer. The shuddering is slight, but is definitely an annoyance because the idle is extremely smooth when not shuddering.

Secondly the car sometimes will seem to run out of fuel at 3k rmps or so (this is my guess from owning a motorcycle with a similar problem in the past). It happened rarely, but has happened about 5 times in the last three months. Basically I will be accelerating, and all of the sudden the engine looses all power and “shudders” hard. The sound changes as well. I will let off the gas, and then press it again and usually after this has occurred there will be a rough spot around the 3K rpms that I must blast through to get to higher rpms. I am thinking a fuel issue, but am not sure.

Thirdly, I sometimes have to crank the engine for about 2 minutes to get it to start. Then it starts and shudders very hard (sounds like an old tractor) for a minute or so. This is also probably some kind of fuel issue, but I am wondering if anybody has a suggestion of where to start. The excessive cranking has only been required twice in the last 5 months. It is almost as if the fuel pump is faulty, but the car will run fine after starting and a few minutes of warm up.

Any suggestions would be greatly appreciated. Thanks in advance.

[coolbear1]

One of mine just went through the same thing. I replaced the electric fuel pump in the gas tank. But it was on my 93 e36. I've never had to replace the pump on any of my e30's.

[mms16]

Did your car idle smoothly before the fuel pump replacement?

Or was it jsut the rought starting and sudden loss of power that were symptoms?? Thanks.

[adabeamer74820]

might be some help but my truck ran like that when there was a leak in one of the vacuum hoses. check those because if they are really old they tend to crack and leak.

[coolbear1]

Check the big black rubber elbow between your intake manifold and your breather box for cracks. I had to replace the one on my 88 convertable because of hard starting and eratic idling.

[dhaus]

Another possible cause is a blown diaphram in the fuel pressure regulator.