Hesitation, won’t rev past 4000 rpm, stalls when warm

[jaquimbayod]

Hi everyone,

I recently bought a 1982 BMW 323i that had been sitting off the road for a few years. Over the past few months I’ve been bringing it back into shape, and during the summer it was running great.

A few weeks ago, however, problems started to appear. While driving on the highway, the car refused to go beyond 4000 rpm and began to hesitate. Eventually it struggled to idle and then died completely. It wouldn’t restart at the time, so I had to leave it parked. After a few hours it started again, and I managed to drive it home, but after about 10 km the same symptoms returned.

Here’s what I’ve done so far:

Replaced the fuel filter and fuel pump

Checked ignition timing (it’s correct)

Replaced the distributor arm

Tested the fuel pump relay

Spark plugs are relatively new

Coil (bobine) is also new

All six injectors are new

At the moment, the car runs fine for a few minutes, but once it warms up and I’ve driven a few kilometers, it starts hesitating again and sometimes struggles to idle.

Has anyone experienced something similar, or have ideas on what else I should check?

Thanks in advance

Julian

[Jeroen]

Hi Julian,

That's annoying! A exhaust gas test would provide some more info but it does sound like a fuel delivery problem. Since you already replaced the fuel pump I am thinking of 2 options, a defective fuel accumulator (the 3rd part underneath the car with the fuel filter and pump) or a defective warm up regulator messing up your mixture. The accumulator you can bypass for testing purposes, to see if the WUR is causing issues you can try with a known good used example perhaps?

Some useful background info here: viewtopic.php?t=18255