W124 with m104, no power at all adove 6k

[Gian Piero]

Hello everyone, recently i bought a 91' japan spec w124 300 ce 24 with the 5 speed automatic transmission, it has a few problems most important were no 5th gear & the gas pumps were almost not working.

The engine runs very smoothly but when you accelerate it tries to stall & then it goes very strongly till 4k-5k then it has no power due to the bad gas pumps, however I just replace both gas pumps with bosch spares & now the car accelerate as before till 6k when the engine become completely powerless (the old m104 revs up to 7k or more)

I'm prone to believe its the distributor & rotor arm, because it backfires between 4k & 2k rpm without accelerate & when cold (lets say morning first start) it missfire quite badly until it warms up
Also the engine set on a low idle, when hot & in D it is around 500 rpm.

Any ideas what the problem might be?

I found an expert on 722.x transmissions & he will solve the 5th gear problem.

Many Thanks!

 

[millo777]

I think you may have already answered your own question. My money would be on a new dizzy and rotor arm. From reading other posts, it seems even new aftermarket items can cause problems on these engines, but a do a search and there are plenty of posts regarding the oem brands, which I think are Bosch and Beru.

I ran a 300TE-24 for a year and remember it driving like a totally different car after a new set of plugs and a thorough cleaning of the throttle body and air intake. Prior to that it had a quite a lot of hesitation in the acceleration. Might be worth a go for the sake of £10 in parts.

Good luck with it as those early m104s with cis really scream around 6k rpm.

 

[Gian Piero]

Plug wires looks fine, i will check & clean the intake manifold, the air filtre looks to be in good shape

 

[kth286]

Hello everyone, recently i bought a 91' japan spec w124 300 ce 24

I found an expert on 722.x transmissions & he will solve the 5th gear problem.

Many Thanks!

Are you aware that 5th gear is electronically selected ?

It is normally an electronic problem, and not a mechanical problem.

You really need an Indie that is familiar with your generation car, with
with diagnostic skills; in preference to a gearbox dismantler.

Where you located ?

 

[Gian Piero]

Are you aware that 5th gear is electronically selected ?

It is normally an electronic problem, and not a mechanical problem.

You really need an Indie that is familiar with your generation car, with
with diagnostic skills; in preference to a gearbox dismantler.

Where you located ?

I'm aware that the 5th is a electronic problem, the car goes very smoothly from 2nd (or 1st) to 4 & stay there but if i take away the n15/1 module it skips 4 & it goes from 3rd to 5th, the things is though that i've been trying to fix it for weeks & i'm running out of pacience, so he (the mechanic) will solve it for me.

EDIT: The selector switch from 4 to D is in a very good shape & working properly, i'm pretty sure all my vacuum lines are conected were supposed to be & all working, haven't check all the lines & mi EZL looks to be worn out but i have no idea how to test it & if it need replacement.

I'm located on Chile, South america.

 

[kth286]

Have you had the fault codes read from pin 13 yet ?

If so what do they show ?

 

[grober]

Do you have the switchable ignition advance and retard knob or do you have any fixed ignition advance resistors that can be changed. Just wonder if the car is set to run lower octane fuel [unleaded] for Japanese market emissions?

 

[balge]

6000 rpm seems high for a 104, never mind 7000?

 

[Niks]

Im pretty sure at 6k the engine is at the end of its power/torque curve, so dont think there would be much left for it to give.. could be wrong though.

 

[Gian Piero]

Have you had the fault codes read from pin 13 yet ?

If so what do they show ?

I haven't been able to get on my hands a MB code reader, also i'm not a very handy on electrical manufacturing to build my own, as soon as i can use one will post the codes from the 13 pin.

 

[Gian Piero]

6000 rpm seems high for a 104, never mind 7000?

Im pretty sure at 6k the engine is at the end of its power/torque curve, so dont think there would be much left for it to give.. could be wrong though.

https://www.youtube.com/watch?v=cQI4MuZI9pA
Not my car but this is how those old m104 went.

 

[Gian Piero]

Do you have the switchable ignition advance and retard knob or do you have any fixed ignition advance resistors that can be changed. Just wonder if the car is set to run lower octane fuel [unleaded] for Japanese market emissions?

I have absolute no idea where it is on a w124 nor if i have the switchable one nor the fixed one.
As for the low idle i think it can be regulated on the throttle body but i don't want to mess around with it without a mechanic opinion.

 

[bolide]

Does the car have a Japanese-market speed limiter? I know some Mercedes did

As KTH said the gearbox problem is most likely electrical. The gearbox ECU samples a number of inputs to decide on gearchanges. If it's missing the speed signal it won't shift into 5th. On the later cars that's fed via the OVP

Nick Froome

 

[Niks]

Retard knob...

It'll be near the suspension struts, on the outside of the firewall. Should be located on the battery side of the engine compartment.

Yours should say EZL on it with N and S (i think).

 

[Gian Piero]

I don't have that, i've seen it in others w124 but not this one.

 

[balge]

https://www.youtube.com/watch?v=cQI4MuZI9pA
Not my car but this is how those old m104 went.

Well it definitely hit 6500 briefly...

They can get 102 octane in Germany though...

 

[Gian Piero]

Mercedes 300 CE 24 power - YouTube
here is more clear, again not my car.

 

[Niks]

If yours is a 300-24 (M104.980), you should have EZL with anti knock control. You can do basic alterations with it but you'll need a trimming socket. It should be located close to the ECU somewhere on yours. It has a fixed number of resistors built into it, so when you turn it to another position, it connects a different resistor which is sensed by the ignition system ECU and that will alter the ignition timing.

 

[balge]

Mercedes 300 CE 24 power - YouTube
here is more clear, again not my car.

Wow, 80 000 - is that km? Barely run in...!

 

[Gian Piero]

Vin: WDB1240511B223374
As the russian vin decoder it is eighter an euro 3.6 AMG which is not, a north america m103 300CE not again & a japan 300ce 24 w124.051