94/320/W124 Help PLS Idling at 2200 Reving falsely at 70mph

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I would very much apreciate some experience here.

I have a w124 94 E320 Coupe (The one with the all electric engine)

When I start it up cold in revs/idles a 1500rpm as it warms up this changes to 2500 odd.

I took it to a specalist who told me the loom was completely gone.....he sent me to a guy who made up 2 looms and did them for me (nice big bill).

However the problem is still there and continues, I have also changed the inlet manifold thinking that was the problem ... it wasn't.

I m now thinking it could be the ECU or more likely a vacume problem somewhere around the plastic manifolds.

Any ideas (I m at my wits end) ? ?

<I adore this car but it's killing me and this problems costing me big time>
 

television

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Hello and welcome. A vacuum leak normally makes the engine hunt. The throttle body could have a faulty switch where it does not switch over to the idle part of the ECU (motronic) or the potentiometer could be open circuit
 

Bolide

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The ECU governs everything on this engine according to an internal fuelling / ignition map and what the sensors tell it. Logically, then, if it's idling at 2500 rpm either the ECU is kaput or it's getting wrong values from the various sensors

Only a systematic approach to fault-finding will cure this. What does a Star machine reveal? What error codes are there?

Nick Froome
www.w124.co.uk
 

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The ECU governs everything on this engine according to an internal fuelling / ignition map and what the sensors tell it. Logically, then, if it's idling at 2500 rpm either the ECU is kaput or it's getting wrong values from the various sensors

Only a systematic approach to fault-finding will cure this. What does a Star machine reveal? What error codes are there?

Nick Froome
www.w124.co.uk

Yes correct Nick but there are two parts to the only ECU running and Idle, this info is needed so that the engine can compensate for things like air con and in N or D when the idle side fails it runs in the fail safe mode of high idle rpm
 

meanie

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In the title you mentioned that it's 'revving falsely at 70mph'.
Could you expand on that?
 
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J
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RE 94 w124 Revs Problem

Guys,

Thanks you for your views, where would I find a star machine?

- To reply to the question above when I going along the motor way in top gear it revs at about 4000 at 70mph.

Cheers

Joe
 
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RE 94 w124 Revs Problem

Guys,

Thanks you for your views, where would I find a star machine?

- To reply to the question above when I going along the motor way in top gear it revs at about 4000 at 70mph.

Cheers

Joe
 

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BE27.10-P-1000-02B Shift points in selector lever position "D" National version model 124, transmission
722.5

Model 124.032/
052/066/092
A CODE 625
H CODE 498
BE27.10-P-1001-02B Upshift without
selection program
1 > 2 Full throttle approx. km/h 35
Kick-down approx. km/h 50
2 > 3 Full throttle approx. km/h 79
Kick-down approx. km/h 86
Upshift delay approx. km/h 48
3 > 4 Full throttle approx. km/h 126
Kick-down approx. km/h 133
4 > 5 Full throttle approx. km/h 192
Kick-down approx. km/h 192
BE27.10-P-1002-02B Downshift without
selection
program
5 > 4 Full throttle approx. km/h 113
Kick-down approx. km/h 179
4 > 3 Full throttle approx. km/h 95
Kick-down approx. km/h 1 119
3 > 2 Full throttle approx. km/h 36
Kick-down approx. km/h 72
2 > 1 Full throttle approx. km/h 16
Kick-down approx. km/h 30


The above are the box shift points

You do nor need STAR on your car as any 38 pin code reader will test the engine. A Bosch service center is a good place to sort out the injection
 
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Many thanks - I m confident I am in 4th gear when it's over reving.

I tried hooking it up to a SNapp on diagnosic machine. The machine couldn't give me any readings :(.

Best regards

Joe
 

meanie

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Then assuming that you are in top gear you have 2 unrelated issues,the gearbox one being potentially very expensive.
Where are you?
 

meanie

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It might be prudent to check the gearbox oil level pronto!
 

television

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Being all electric (94) would my car have a potentiometer ?

Thank in advance

Yes it does, by the way the gearing for these cars was about 20 mph per 1000rpm and are you sure that you do not have the 5 speed box
 

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