Car won't go over 4500RPM while running

[Godlama]

Hello , my 1992 ( Swiss version ) 500E is having a bit a problem now.

When cold , like extremly cold like first start , I can pull over 4500RPM while driving , but after that.. Car starts to cut and engine shuts down.
I suspect a fuel pump problem , but i'm not sure ? It also feels like the car has not his full power when I try to kick down.

What has been recently replaced :
-Coils
-Spark Plugs ( Straight from MB )
-Spark plugs wires
-Rotor caps. ( it's even worse since )

anybody have an idea ? I'm quite lost in this , for the DTC I tried to pull them out with my SDS , but it seems like I have a connection failure..

Thanks in advance.

Manu.

 

[gsxr]

When warm, does the engine pull to exactly 4500 and then hit a limiter of some sort? And it's always 4500rpm, not higher or lower? That sounds like possibly the computers limiting the revs, maybe due to a signal from the gear position indicator switch (S16/1).

You'll need to get your SDS working to check codes, particularly for the E-GAS module (EA/EFP). SDS will also show live data to verify if the gear positions are reading correctly. You can get basic codes with a blink code reader.

If your SDS has never worked for all modules, you may have a defective 38-pin cable - verify all 38 pins have continuity on both ends (from connector to connector).

BTW, welcome to the forum!

 

[kubasz]

Going 4500RPM on cold motor is not what i would do but i may add that engine shuting off after high RPMs would ring a "catalytic converter failing" bell in my head.

 

[Godlama]

When warm, does the engine pull to exactly 4500 and then hit a limiter of some sort? And it's always 4500rpm, not higher or lower? That sounds like possibly the computers limiting the revs, maybe due to a signal from the gear position indicator switch (S16/1).

You'll need to get your SDS working to check codes, particularly for the E-GAS module (EA/EFP). SDS will also show live data to verify if the gear positions are reading correctly. You can get basic codes with a blink code reader.

If your SDS has never worked for all modules, you may have a defective 38-pin cable - verify all 38 pins have continuity on both ends (from connector to connector).

BTW, welcome to the forum!

Hello , yes it's exactly that 4500 RPM then shutting down , but when I'm in neutral , no problem I can go over 4500.
Ok I will check about it , it's working on ODB2 etc but I guess my 38 Pin is failed.

and thanks for the welcoming help !

Going 4500RPM on cold motor is not what i would do but i may add that engine shuting off after high RPMs would ring a "catalytic converter failing" bell in my head.

Hello I tried without cat , still does the same..

 

[gsxr]

Hello , yes it's exactly that 4500 RPM then shutting down , but when I'm in neutral , no problem I can go over 4500.

That sounds like the problem. The engine should not go above 4500 in Park or Neutral, but should pull to the rev limit only in gear.

Ok I will check about it , it's working on ODB2 etc but I guess my 38 Pin is failed.

See what other modules you can connect to with HHT-Win. If it will connect to only 1 or 2, you likely have a defective 38-pin cable. Search the forum for details, this is a common problem... the Chinese vendors cheaped out and removed most of the 38 wires to save money, not realizing (or, not caring) that this would render the cable useless for may 1990's vehicles.

If HHT-Win works with every module except EZL/DI, that is a different problem, it can be a defective MUX. This was also discussed in the past on this forum.

 

[Godlama]

That sounds like the problem. The engine should not go above 4500 in Park or Neutral, but should pull to the rev limit only in gear.



See what other modules you can connect to with HHT-Win. If it will connect to only 1 or 2, you likely have a defective 38-pin cable. Search the forum for details, this is a common problem... the Chinese vendors cheaped out and removed most of the 38 wires to save money, not realizing (or, not caring) that this would render the cable useless for may 1990's vehicles.

If HHT-Win works with every module except EZL/DI, that is a different problem, it can be a defective MUX. This was also discussed in the past on this forum.

I'll try to replace it , do you by any chance got any part number ?

 

[gsxr]

I'll try to replace it , do you by any chance got any part number ?

This part is NLA so you'll need to test / repair your existing one. First verify it's adjusted properly though.

More info at this link, see post #61-#74 for details about the internals and potential repair.

 

[Godlama]

When warm, does the engine pull to exactly 4500 and then hit a limiter of some sort? And it's always 4500rpm, not higher or lower? That sounds like possibly the computers limiting the revs, maybe due to a signal from the gear position indicator switch (S16/1).

You'll need to get your SDS working to check codes, particularly for the E-GAS module (EA/EFP). SDS will also show live data to verify if the gear positions are reading correctly. You can get basic codes with a blink code reader.

If your SDS has never worked for all modules, you may have a defective 38-pin cable - verify all 38 pins have continuity on both ends (from connector to connector).

BTW, welcome to the forum!

After reasearch on the forum I found , this part number 000 545 62 06.. By your indications (S16/1) it's the neutral switch that should be replaced ?

(found it here HOW-TO: Replacing Neutral Safety Switch (S16/1) | "HOW-TO" Tutorial Articles)

 

[Godlama]

This part is NLA so you'll need to test / repair your existing one. First verify it's adjusted properly though.

More info at this link, see post #61-#74 for details about the internals and potential repair.

Yeah i've seen it's NLA. I Found out that : Mercedes Getriebesperrschalter (ersetzt A0005456206)

Looks like a reman one. They say they modify it to match perfectly the PN A0005456206 , i'll give it a shot.

 

[gsxr]

Don't replace it just yet. ADJUST it first per the FSM procedure here. Then bench test it next. The BEST test method is using SDS / HHT-Win to view live data as you move the gearshift into each gear position.

If you confirm your NSS is indeed faulty, you could gamble on the €300 Kurth modified replacement.

 

[Godlama]

Don't replace it just yet. ADJUST it first per the FSM procedure here. Then bench test it next. The BEST test method is using SDS / HHT-Win to view live data as you move the gearshift into each gear position.

If you confirm your NSS is indeed faulty, you could gamble on the €300 Kurth modified replacement.

I will do it. I forgot to mention that ; sometimes , when I put the car to D it just won't drive , need to put the selector just a lil bit higher then it's engaging. It's errating.

I'll fix my SDS then I'll come back for giving feedback.

 

[gsxr]

OH! Also verify your shift linkage bushings are good. This may not help with the 4500rpm issue, but should help with the shifter position.

Details are in this thread.