The only proper fix is to get a throttle body made in 1998 or later. Plenty of used units to be found on eBay.

Always replace the gasket whenever R&R'ing the unit.

 

hey sbaert I replaced the gasket already but I've been swapping throttle bodies all day, 3 different ones in total just to test what's wrong with the car.

I've seen people succesfully fix their throttle bodies and I'd like to if I can. I have literally already rewired one though and it's quite the task. You don't think a diagram of the sort I'm after exists do you?

 

I had re-wired mine too. I think this is the diagram you are requesting.

There are lots on threads on here about M104 throttle body re-wiring do searches on the forum- I found lots of info on the subject on here before I tackled mine. It’s 100% spot on now it’s re-wired.

However- were I able to snag a good used one I would do that next time instead.

 

Could I ask where you put the multimeter needles when testing ohms for each connection? Do I need to power it with 6v or?

 

That's the one thank you so much and yeah I've read through all the threads but attachments are expired and I couldn't find anyone that talked about matching the pins to locations on the boards. Can I ask what gauge wiring you used for the wires and then what for the power + and -?

 

I had posted about this before myself- this thread is good too
http://www.benzworld.org/forums/w124-e-ce-d-td-class/2476809-throttle-body-harness-re-wiring.html
http://www.benzworld.org/forums/w124-e-ce-d-td-class/1448549-how-rewire-m104-throttle-actuator.html
This is what I posted shortly after re-wiring my own ETA
Its not a difficult job just time consuming. Get yourself;

Max 30w Soldering Iron with pointed Tip
Solder Sucker (To clean the Circuit Board before poking through the new wires)
Min. 6m Coil of 0.5mm Cable +
Min. 3m of 1mm Thin Wall Cable.
(Just regular Correct Auto Cable- most are high temp & Fuel resistant- check spec before you buy just incase)

Opening the side of the Throttle body to access the circuit board is easy. Security Torx Bits needed. Just be careful with the circuit board & don't put too much heat into it or you will destroy it in seconds.

The round Plug needs to be cut open. See Pic below. Hacksaw into it only about 4mm deep all the way around exactly at the location shown. Then split apart with a screwdriver. You will be able to prise out the small round block holding the pins.

I used tape to hold the pins in place. Then I replaced only one wire at a time. Heat the pin & the old wire will come out. Then re-heat & push the end of the new wire in. Then add a little fresh solder to finish. The thicker gauge wire is for the Motor terminals.

Please note you only need to replace the wires feeding into the circuit board from the round plug. The few small wires you will see in the Throttle Body itself do not degrade.

Glue the round plug back together & use loom wrap to re-wrap all the wires again.

Get a mulitmeter with a continuity test function built in. You touch one pin and then connect to the other end and the meter will beep when the connection is good.

 

Thank you, I used 1mm wire for all the wires. But for the continuity test what do you mean touch the pin and then the other side?

 

Don’t worry about the continuity test- if you have soldered the wires all will be fine.

 

I just bought the .5mm and 1mm wiring but the .5mm seems far too thin? Did you mean .5mm outer or inner diameter? I'm guessing outer because .5mm inner is way too thick. But outer seems too thin compared to the old wires.

Cheers

 

The gauge of the wire refers to the actual copper core. Anything thicker than 0.5mm will not poke through the circuit board properly for soldering. The sheathing thickness (Outer) does not matter- the thinner the better.
This is because if the cables are too thick outer diameter then they will not all fit through the cable outlet in the Throttle body.

 

note that metric wire gauges are 'square millimeters', which are not the same as diameter. a 1.0 mm^2 wire's conductor is about 1.3mm in diameter, this is between 16 and 18 AWG. a 0.5 mm^2 wire is 0.80mm in diameter, between 20 and 22 AWG.