Herzlich willkommen

[Andrey Nikolov]

Hello Hello

I fix the truck...it was my foult. I didn't attached Verteiler correctly .

I play with a little and the best/stable idle is at 5 deg.

Interesting is the way Jetronic controls the idle ignition advance . Vacuum line to Verteiler is controlled by solenoid. On 0 throttle solenoid is on and block vacuum to Verteiler, when throttle is applied solenoid shut off and vacuum is applied to Verteiler and respectively advanced ignition.....cool retro solution.

In next MonoJetronic models (golf 3, astra etc)...ignition is fully controlled by ECU (there is no weights and vacuum actuator in Verteiler)....just for the record.

[Andrey Nikolov]

Hello,

I need to address alternator. This morning I leave truck to idle for an hour and 2 thing happend:
- engine temp not surpass 65 deg
- battery is not charging properly
...after hour I shut down the engine - restarted again - then shut it down again and start to turn real slow. Check the voltage on battery 11.8V.

I look the possibility's ...smaller pulley to alternator...mmmm... current is 50mm, smaller then that is not good for the belt and power transfer. To relocate alternator further front and to drive him thru cooling fan belt as far as fan pully is bigger...to much wirk. Don't know really.

[MagMog]

Guuden,

If there is still a DC Generator in the Mog, it needs more RPM to deliver electricity.
Bretter Change to an AC Typ. It will charge even at idle.
The temp may bie a prob of the thermostate. Does not close ore opens at too low temp.
Put it into water with a thermometer on a stove and see when it opens.
Should at 80° to 85°C.

Gut Mog!
Justus

[Andrey Nikolov]

Hello MagMog,

The truck is converted to 12V (starter and alternator.....and VAG Mono Einspritzung). The problem that ECU targets very low RPM as far as is for 4 Zylinder Engine instead of 6 and 'see's 1 impulse more per RPM, so probably idle RPM's are around 750. It's complicated to rise the idle RPM's with this very old systems, as far as they are based on TPS and RPM (Alpha N) and when you mechanically rising the idle, you should adjust the 0 point of TPS sensor too.....which I don't want to mess with...for now!

Options are:
- mechanically rise throttle and readjust TPS sensor
- make smaller alternator pulley
- relocate alternator further front in order to be driven from fan belt
- connect ECU to separate Hall sensor (different from those one in Verteiler) which reads 2 points/toots on crankshaft pulley

[Andrey Nikolov]

Hello

need some help. When I tried to 'optimize' electrical system, I disconnect a lot things ...fuse box. So now I need wiring diagram, but with colors marking of cables. For now I was able to restore blinker, Innerbeleuchtung, horn... I still need to do lights (low, high, Standlicht, Stop, rear light, Scheibenwischer...so weiter.

I made some upgrade too. I install combi schalter to the steering column (from 207, 308 etc vans from the 80-ties)

schalter.jpg (60.34 KiB) 1609 mal betrachtet

[Helmut Schmitz]

Hello Andrey

So now I need wiring diagram, but with colors marking of cables.

google helps

Schaltplan_Unimog_404-115.pdf

(1.67 MiB) 59-mal heruntergeladen

[Andrey Nikolov]

Herzlichen Dank!!!

[Andrey Nikolov]

Hello

I plaid this evening with idle ignition advance....try to rise idle RPM.

Unfortunately when I rise advance to 15 deg, the RPM's goes up, but engine is little bit 'shaky'.

When I set advance at previous 5deg, engine idles so smooth, that you can put a coin on valve cover .

After I deal with lights...next mini project will be...maybe:
- power steering from 406, I have all components already
- relocate radiator expander tank
- re-rout cooling hoses and new thermostat body (in which can be put different elements...easy to find)
- new pulleys in order to rise rpm's at alternator
- maybe electrical cooling fan

[Andrey Nikolov]

Hello,

some help needed

I can't figure out...how brakes lights work....which color cable goes back of the truck.

Why Bremslichtschalter ....sw/ro cables) ...both goes to Lichtschalter? What is the idea?

IMG_20221007_172829.jpg (1.83 MiB) 1291 mal betrachtet

[Jürgen-Fahlbusch]

Hallo Andrey,

Thers are two reasons, why the cable from brake switch goes to the main light switch.
1. The 404 was a military truck. Therefore it was necessary for some reason to switch the normal brake light completely off.
2. The 404 has normally a combined brake and turn light.
On your attached diagram the cable to the back is shown on right side "Steckdose 12 polig für Aufbau u. Schlußleuchten"
The brake / turn light right is contact "I" with green/red cable
The brake / turn light left is contact "B" with white/red cable

[Andrey Nikolov]

Hello,

I have some experience with stand alone ECU's and couple of project during the years and more or less I know, how to create fuel/ignition tables and how to monitoring AFR (Lambda) and interpretate all this data. So to put fuel system from one engine to another and hope that will works properly.....hm.

Any way...this days I dig out an ancient AFR controller ..PLX is the brand...weld a bung on exhaust, assemble the system and start monitoring:

WITHOUT LAMBDA
Initially I run the engine without connecting 0-1V output of controller, so practically ECU works in some kind of limp mode (in case of some of the sensors are missing). ECU holds AFR around 12,5...relatively rich condition, almost in all RPM's

WITH LAMBDA
Quite responsive...didn't expect so.

On idle targets 14,7 - pretty stable

Obviously there is acceleration enrichments, slam the throttle and for second AFR goes to 10.5

There is 'overrun cut' ...when you release completely the throttle in high RPM's AFR shows LEAN for brief moment, which means that ECU cut the fuel

When you cruise for more that 3 seconds (constant throttle) it starts to target again 14,5 AFR


So surprisingly normal behavior of this 'ancient' VAG ECU.

idle AFR.mp4

(1013.16 KiB) 55-mal heruntergeladen

[Andrey Nikolov]

just few pictures

here is the new home of Jetronic ECU

jetronic.jpg (227.96 KiB) 965 mal betrachtet

TBI

tbi.jpg (259.44 KiB) 965 mal betrachtet

ignition system

ignition.jpg (288.73 KiB) 965 mal betrachtet

[Andrey Nikolov]

fuel pump.jpg (238.04 KiB) 952 mal betrachtet

fuel pump

tbi2.jpg (266.69 KiB) 952 mal betrachtet

TBI from inside cabin

[Andrey Nikolov]

hallo

I aways know that if something work - don't touch it. But...the engine oil start to be 'milky'. I checked cylinders with camera and it's appear coolant leakage in 1-st cylinder. Hmmmmm ..... I go around this problem over a month, but today I remove the head. Everything seems to be ok...but all rocker arms are with pretty big wear. I've checked the camshaft lobes, they in specs. Faaaaaaaaa@# now I need to buy from somewhere 12 rockers. I\ve already bought head gasket set. Tomorrow I'll take the head to machine shop for resurface, valves etc. I

[Andrey Nikolov]

Hello

I still try to track cheap rocker arms, till I wait for machine shop to do the head. What is tourqe specs for the head?