89 325i M20 swap on a 84 325e

[joshEbro]

Hey guys what’s up. 2 questions, I bought a 1985 bmw 325e about 2 months ago. It had its engine swapped out for a 1989 bmw 325i engine. when I turn on car it sounds fine, as soon as it warms it shakes very little like it has a misfire but when I drive it drives fine. It only shakes when I’m still. I’ve change spark plugs, spark plug wires, distributor, ICV. I changed computed as well and didn’t seem to do anything. Any ideas?

Second question is wiring harness plug and play from a 325e to a 325i engine swap? I looked at the harness connecting to the computer and it seems like the modified it?

[Andre3127]

Hey guys what’s up. 2 questions, I bought a 1985 bmw 325e about 2 months ago. It had its engine swapped out for a 1989 bmw 325i engine. when I turn on car it sounds fine, as soon as it warms it shakes very little like it has a misfire but when I drive it drives fine. It only shakes when I’m still. I’ve change spark plugs, spark plug wires, distributor, ICV. I changed computed as well and didn’t seem to do anything. Any ideas?

Second question is wiring harness plug and play from a 325e to a 325i engine swap? I looked at the harness connecting to the computer and it seems like the modified it?

You mean an idle misfire?

My car had that before I pulled the head for a bad head gasket job done by a previous owner. I'm 80% sure the misfire was caused by an injector. You didn't mention that you had checked injectors on your car, so that's where I'd start (and will be starting on mine).

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[joshEbro]

You mean an idle misfire?

My car had that before I pulled the head for a bad head gasket job done by a previous owner. I'm 80% sure the misfire was caused by an injector. You didn't mention that you had checked injectors on your car, so that's where I'd start (and will be starting on mine).

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Yeah idle misfire, I actually haven’t checked the injectors, i go ahead and do that next hopefully that will fix the problem thank you bro

[325e '87]

In my experience if the engine won’t idle nicely you need to confirm;

Idle air control valve
Throttle position switch
Coolant temp sensor (the 2 wire prong one)
Crank sensor
Oxygen sensor
Vacuum leaks

If all these things are working properly then you would move on to individual fuel system components, like fuel pressure, filter, harness connector

The ignition system, plugs, wires, coil, distributor and rotor

It could simply be the oil fill cap not sealing or the dipstick o rings are dried up

[joshEbro]

In my experience if the engine won’t idle nicely you need to confirm;

Idle air control valve
Throttle position switch
Coolant temp sensor (the 2 wire prong one)
Crank sensor
Oxygen sensor
Vacuum leaks

If all these things are working properly then you would move on to individual fuel system components, like fuel pressure, filter, harness connector

The ignition system, plugs, wires, coil, distributor and rotor

It could simply be the oil fill cap not sealing or the dipstick o rings are dried up

This is perfect I’ll do one by one on this list thank you brother

[325e '87]

Cool, do keep in mind that there are many people here that are far more knowledgeable than I so keep searching and asking stuff.

[gunsnbacon]

I’d try the following since they are free:

Valve adjustment
ICV penny trick
Check for vac leaks
Clean injectors

[cscracker]

On the wiring harness question, there are two main versions of the Bosch Motronic system used in e30s, 1.0 and 1.1/1.3. The former uses a 35-pin connector, the latter a 55-pin. Given the age difference, it was probably converted from 1.0 to 1.3. Lots of detailed information on the Bosch Motronic and Jetronic engine management systems here:

http://www.e30zone.net/e30zonewiki/index.php/Engine_Management