E320 missing

[imadoofus]

For a wee while, when I start my car everything is fine. Then, when the first stage of the choke comes off, and the idle speed drops, it appears to drop a cylinder. Then it's very slow to rev, and won't really pull. Restarting the engine fixes it.

Today, however, I had the problem, and restarted about a dozen times (and drove about three miles), but couldn't clear the problem.

I have just been out to check on things, and I whipped out the plugs, which are all in perfect condition and perfectly gapped. Restarted the engine, and it was perfect too. So I put the engine back together again, and tried it again. Problem came back, and won't clear

I have noticed that much of my top loom is wrapped in fabric tape. You probably know what I'm thinking now...

Is the loom original, and is that my problem?

TIA

PJ

 

[jaymanek]

loom on your engine, if its the original one then it needs changing..

We changed the plugs so I know they are perfect

 

[imadoofus]

I thought they looked new...

So a fabric-wrapped loom is an old one then?

 

[jaymanek]

Cant say for certain but if it looks old then chances are it is..

 

[imadoofus]

That's the thing. It doesn't look old, although I have notice a crack in the insulation of a wire just as it leaves the water pump.

New looms are main dealer only?

 

[grober]

Dealer only to purchase but a relatively easy DIY if you use the old one as a template. http://www.mercedesshop.com/Wikka/M104WireHarness

 

[BlackC55]

Peel back the tape and have a look.....If you are brave enough

 

[imadoofus]

Peel back the tape and have a look.....If you are brave enough

I have (a tiny bit), and it looks OK.

Grober's link is interesting, because this photo could be of my car:

Which suggests the loom is worn out, but this photo could also be of my car:

Which is what was giving me (false?) hope...

 

[jaymanek]

Its likely that the loom has degraded around something to do with the ignition side..i.e not providing a spark on a cylinder..

 

[imadoofus]

Its likely that the loom has degraded around something to do with the ignition side..i.e not providing a spark on a cylinder..

Yeah, that's what I suspected, seeing as it's intermittent...

 

[grober]

Not wishing to sound alarmist but a ignition misfire which probably originates in the low tension wiring side as has been said , (unless you have a coil on the way out) ,can eventually damage the ECU ignition output stages which can prove expensive so I wouldn't delay in getting it checked out.

 

[imadoofus]

Not wishing to sound alarmist but a ignition misfire which probably originates in the low tension wiring side as has been said , (unless you have a coil on the way out) ,can eventually damage the ECU ignition output stages which can prove expensive so I wouldn't delay in getting it checked out.

My ECU was rebuilt in January 2007, at which time I replaced all the coils too, so hopefully, they're OK for the moment. I can't really use the car now anyway, and I'm waiting for Mercedes to phone me back with a price.

Jay. I don't expect you to remember this, but at my last MOT, I got an Emissions Check report which says "For Non-Catalyst Equipped Vehicles". Does that definitely mean I don't have a cat, or is it possible I got the wrong form?

 

[Mark300SL]

I found it was the actual act of removing the coilpacks that caused my problem - the cables to the coils were moved and that was enough!


If you have the time and the patience you can do a very effective repair with heatshrink/insulating tape and cloth tape for about £30
Mine took about 8 hours but I KNOW for sure its now OK. I have ordered an ECU and coilpacks but I am completely confident in the harness


http://www.mbclub.co.uk/forums/showthread.php?t=51471&page=3

 

[imadoofus]

If you have the time and the patience you can do a very effective repair with heatshrink/insulating tape and cloth tape for about £30
Mine took about 8 hours but I KNOW for sure its now OK. I have ordered an ECU and coilpacks but I am completely confident in the harness


http://www.mbclub.co.uk/forums/showthread.php?t=51471&page=3

Thanks Mark, I'd seen your thread on this before.

Time I can find. Patience I can force. I can even summon up the required skill. I'm just not sure I have the courage, that's all...

 

[jaymanek]

I wouldnt go by that form IMD as the computer uses pretty generic info.. Im sure your car would have a cat..

 

[Roger Jones]

"Does that definitely mean I don't have a cat"

Drop the VIN into the Russian site:

http://old.mbclub.ru/mb/vin/?lng=eng

and if code 620 is on the list it indicates "emission control system vehicles with catalyst technique (#1089; 01.03.1985)".

 

[kth286]

imadoofus

If you now have the hang of that code reader, plug it into number 8 and give us the codes that show.

That will help with the next steps.

 

[imadoofus]

Drop the VIN into the Russian site

Yes I do have option 620

 

[imadoofus]

If you now have the hang of that code reader, plug it into number 8 and give us the codes that show.

That will help with the next steps.

Will it? I got no faults

 

[kth286]

Imadoofus

You plugged it in since you have these faults ??

So, how many times did the light blip ??????