Engine cuts out momentarily while accelerating and dies at idle unpredictably

[Chilezen]

The problem is un-reproducable, I don't know what causes it. She just "chokes" at random, usually far apart intervals.

Engine details: recently rebuilt, but the problem existed before.
Has most new parts that are associated with a rebuild, but only engine-specific parts. I've relied on r3v and the bentley and other forums for correct parts to use.

Air: I haven't done a vacuum leak test, but given that all the seals are new, I'm doubting there's an air leak.

Spark: Bosch WRLC+, new cap & rotor, old wires.

Fuel:The tank pump (afaik) hasn't been replaced, the inline pump is maybe a year or two old, and the fuel filter is a couple weeks old. No idea how old the injectors are. It has to be a fuel related issue, I just don't know how to check any of it.

She is not registered (failed smog), so I don't drive her much, maybe once a week to keep things circulating. For the most part, it drives fine, normal operation. It exhibits these two characteristics under a great range of circumstances; I haven't found a specific instance to cause it to stumble. I'm on a limited budget but I do have time.

[FLG]

Usually a cps issue. Does the tach drop out and not follow engine rpm during one of these incidents?

Sent from my SCH-I545 using Tapatalk 2

[Chilezen]

Does the tach drop out and not follow engine rpm during one of these incident?

I should also mention the gauges don't work. Sorry, wish I could tell ya.

Edit: is there a way to test the cps on its own?

[Chilezen]

Anyone else have ideas?

[flyboyx]

the main relay. it is located on the driver's side inner fender by the air cleaner. there is a bank of 3 relays under a little plastic cover. the small one(usually white, sometimes silver) is normally the one closest to the radiator/front of car.

[Chilezen]

Someone with an '85 325e is junking his car tonight and letting me grab some things. Do you know if the order is the same?

Edit: to answer my own question, Bentley says
"The main relay may be located in an adjacent
position. To check if the main relay has been
correctly identified, inspect the wires leading to
the relay socket. There should be two large (4
mm) wires leading to the main relay socket."

[Chilezen]

A new relay has not solved it. The car still hiccups/chokes randomly.

[///M42 sport]

clean out your idle control valve?

sounds like similar issue I had, sprayed some brake cleaner into the ICV. Hasnt happened again

[Chilezen]

clean out your idle control valve?

About a year ago I did, when I really started to look for a solution. However this problem has existed longer than that.

I don't mean to contradict you, but I don't see how the ICV would cause stumbling under acceleration if the throttle is partially open. But I will clean it again.