E200 - 4000rpm cutout

[TaqMan]

Hi Guys,

Update to my earlier thread re: ABS light on, erratic cold idle and 4000 rpm cut out on my E200 94reg. (16v)

Replaced the OVP and cured two out of three!

Still got the 4000rpm rev limiter.

Any suggestions - it does it in all gears and all conditions - 4000 rpm and blerrrrgh it starts missfiring.

any suggestions please

Cheers

 

[marnix]

Looks like the car is in safe mode.
Could be just needs to clear the fault code or it could be the Lambda sensor for the emissions that is causing this

 

[TaqMan]

Ta,

The Lamda sensor has a distinct chance of being a bit iffy.

can it be tested? ie buypasses or something to see if condition improves or gets worse

Cheers

 

[television]

Your fuel pump relay contains the engine speed limiter, is it the right one for the car, had a 126 with wrong relay, if you have relay 003 545 17 05 that cuts at 4k

Malcolm

 

[TaqMan]

Hi Television,

Thanks again for helping!

Where is the relay - behind the battery? There isn't much back there, as I recall, a green coloured relay thingy next to the OVP and the ecu.

What would cause the limiter to suddenly cut in as the car would happily rev to 6000 before

Thanks

 

[television]

Hi Television,

Thanks again for helping!

Where is the relay - behind the battery? There isn't much back there, as I recall, a green coloured relay thingy next to the OVP and the ecu.

What would cause the limiter to suddenly cut in as the car would happily rev to 6000 before

Thanks

I think it is up front with fuse box somewhere, can check, these units have an Eprom that has the speed limiter info, if this device loses it memory then maybe they de fault at 4k. the one I have here cuts at 4k, its always puzled me as I cant think what engine cuts at that speed, only deisel maybe.if yours is the same number could be interesting.
Have a word with Luisoliver Regarding Relay in this section

malcolm

 

[jberks]

The rev limiter cuts in at 4k in neutral. Don't know enough about how it works but perhaps there is a sensor fault and it doesn't know you're in gear?
Just a thought.

 

[television]

The rev limiter cuts in at 4k in neutral. Don't know enough about how it works but perhaps there is a sensor fault and it doesn't know you're in gear?
Just a thought.

Though a replacement cured the 126, these units must have dual info, I will look up the spec of the PIC Eprom during the day.

thank JB, Malcolm

 

[TaqMan]

You guys are all stars!

Thnaks for the help.

Jberks - its a (say it very quietly) manual

and the cut out happens in all gears and neutral.

Thanks again

Taq

 

[television]

You guys are all stars!

Thnaks for the help.

Jberks - its a (say it very quietly) manual

and the cut out happens in all gears and neutral.

Thanks again

Taq

It could be that the Pic serries Eprom loses part of its memory,or is it a switch somewhere that operates when the car moving, cant work that piece out yet as to where it could be on a 8manual.

malcolm

 

[TaqMan]

More Info

Ok I've been on a relay hunt.

I found 3 behind the fuses

A small white jobbie in position A

A medium black one 201 821 0047 - winker relay I think.

And a Huge one 126 542 0332

are any of these the prime candidate for the fuel pump relay?

The fuel pump relay replacement at euro car parts is £12 + vat which seems way to cheap for one of the biggies

The OVP was £45ish

Cheers for any info

Taq

 

[TaqMan]

Update

Hi All,

Just an update. - I replaced the OVP as per the earlier thread, This cured 2 of three probs - ABS and erratic idle but not the 400rpm cutout.

But after hunting for relays, disconnecting and reconnecting various black plastic boxes the 4000rpm cutout seems to have cured itself.

So thanks to all for your imput - my merc's happy again!

Cheers

Taq

 

[Stevie A]

It must have been in limp home mode maybe due to the OVP being faulty in the first place and you've managed to reset it.

 

[tom7035]

As has been said before, a spray can of electrical contact cleaner is a MUST in MB toolkits!