Raw fuel smell in oil, engine running bad

[Raghib]

Hello,
I have just swapped my engine to another unknown m20b20 jetronic, 1984, and when I fired it up, I realized that the engine is running bad, like it was missing a coulpe of cylinders. The exhaust gas smells very badly of fuel, and almost white heavy smoke comes out, it makes me ill and irritates my eyes badly. Also realized that the eninge oil smells strong of raw fuel.
I have checked that all cylinders have spark going to them. I have already replaced all vaccum lines, intake boot and the AFM itself, all fuel lines, and filters. New engine oli and filter. New plugs, and new timing belt and coolant and so on. I have also checked the Fuel pressure, and this is good. The tank is full with fresh fuel.
When the engine is cold, it fires up quickly with just turning over the key. But when it is a bit warm, you have to remove the intake boot to the AFM to get it going, otherwise it wont start. Either way, when the eninge is cold or not, the idle is not perfect, and you are not able to rev the engine at all when it is warm.
Where do I start?

[Bonymaenjack]

Hello,
I have just swapped my engine to another unknown m20b20 jetronic, 1984, and when I fired it up, I realized that the engine is running bad, like it was missing a coulpe of cylinders. The exhaust gas smells very badly of fuel, and almost white heavy smoke comes out, it makes me ill and irritates my eyes badly. Also realized that the eninge oil smells strong of raw fuel.
I have checked that all cylinders have spark going to them. I have already replaced all vaccum lines, intake boot and the AFM itself, all fuel lines, and filters. New engine oli and filter. New plugs, and new timing belt and coolant and so on. I have also checked the Fuel pressure, and this is good. The tank is full with fresh fuel.
When the engine is cold, it fires up quickly with just turning over the key. But when it is a bit warm, you have to remove the intake boot to the AFM to get it going, otherwise it wont start. Either way, when the eninge is cold or not, the idle is not perfect, and you are not able to rev the engine at all when it is warm.
Where do I start?

Are you losing coolant , check the inside of the rocker cover for a build up of sludge .has the oil level risen . it could be leaking injectors possibly causing overfueling , blue temperature sensor defective . Check them all but don't replace any items en block , eliminate the potential problem rather than just changing everything

[Raghib]

I am not loosing any coolant, and the coolant still looks New and blue. The oil level dosent seem to be risen yet, but I am wathing it.
No built up sludge or any residue on the top od rocker cover, it is almost clean.
I dont have any blue temp sensor. I only have One dark Brown, but I am not sure it is connected to the correct connector, because when unplugged, there is No difference in idle.
So please guide me on what to do Next. I have many connectors beside the thermostat housing that i dont know what is for. Maybe i can upload a photo

[Raghib]

The first picture you see here is My old engine with the old thermostat housing and total of 4 sensor

Screenshot_20210303_084604_com.android.gallery3d.jpg

Here you see My New installed engine with 2 plugs in the thermostat, missing the 2 sensors. You can also see the connectors i am talking about.

Screenshot_20210303_084622_com.android.gallery3d.jpg

[flybynite]

The Jetronic engines are, always have been and always will be a pain in the ass to deal with.

There are many versions of the Jetronic and people that know them inside out are few and far between these days.

What you have put in looks like a later jetronic engine. Ideally it should have come with its engine loom. You may be able to make the loom fit the new engine but it will be a time consuming job even if you have the correct wiring diagrams.

I would say your old engine was ECU code 301 and the new engine needs 309

My guess is it is something like the cold start injector running all the time

Have a read through the Wiki here

https://www.e30zone.net/e30wiki/index.p ... ime_Switch

Better still get an early orange haynes manual from ebay

For the time it takes to sort a Jetronic properly it is better to convert it to Motronic (especially as you are not keeping it strictly original)

https://www.e30zone.net/e30wiki/index.p ... tronic_1.3

[Raghib]

I think you are right. It is a pain to work on. I am used to Motronic, so I am looking for a replacement engine complete with everything, because anything else is going to cost me much more. While i am at it, i was thinking to throw a 325i engine in it. But the only one I could find here in Denmark where i live, is one from a 325IX. Would you know, if it was possible to swap only the oilsump and inside gears for the front shafts, and then it was plug and play?
Otherwise I will look at a complete 320i with motronic 1.3 and swap it.