Sick 95 CL500

[jibcl500]

All

I have a 95 CL500 come in for some work, its identicle to my CL500. Ive just drive the CL about 12 miles from Cambs to Ely, at traffic lights I can feel the engine hunting or misfiring, if I put my foot down from stand still it hesitates but if I accelerate gently its ok.
I plugged the laptop in and it shows no faults, I replaced all the plugs, Ive swapped all the ignition packs from my car and swapped the air flow meter from my car, still no change.
I found a breather rubber tube at the top of the engine was perished so I replaced that with mine, still no change.

Anyone any ideas, I beginning to think there is a vacume leak either on the other rubber tubes as they pull off easily or the inlet manifold has a leak.

jib

 

[Richard Moakes]

As you say it sounds like it's running lean, if it isn't pulling air somewhere, perhaps the fuel pressure is low or the oxygen sensors are no longer reading correctly?

Cheers,

Richard

 

[television]

How about the injectors

 

[jibcl500]

Good point havent checked them, what I have done tonight is clean all the 3040amp fuses as the blades where very dirty, Ive also cleaned some other connections around the fuse box area as it is evident water has been getting into that area. Seems to run better but still has hesitation like a complete shut down it I floor it but that could be some connections are still wet from WD40.
The only other thing I can think of is the ETA failing as Ive heard these are a common failure on the W140 and £2500 to replace. Cars done 130,000.

jib

 

[Mr Teddy Bear]

Have you looked at the plugs?
My old Rover 216GSI started doing smething similar back in 94 that was a combination of Sainsburys Petrol and a half mile commute to work.
By the way Hunting is surging at tickover, thats mixture too rich, back in the days when one could adj' the main jet. However modern systems dont allow that so I'd say bunged up injectors=driping fuel poor spray pattern and atomisation ?
Tim

 

[jibcl500]

Spark plugs are new, injectors will be checked tomorrow,

jib

 

[Mr Teddy Bear]

What colour were the old ones?
white=weak
sand=right
black=rich
TB

 

[jibcl500]

Old plugs looked quite healthy a sandy brown colour, I only change them for a new set because 8 plugs from MB where £16 and 4 of the old plugs where a different brand.

jib

 

[jibcl500]

Ok this is the latest, with the ignition on but engine not running there is a buzzing noise coming from the ETA if the ignition is on for 30 seconds of so the buzzing gets more irratic and louder or in and out of a high a low buzzing, the throttle buttlerfly also twitches.

Me thinks the ETA is on its way out.

jib

 

[jibcl500]

Well Ive swapped the ETA from my car and although mine is quieter the car still runs the same, ive also tightened up the inlet manifold, it was tight anyway seems to be running better but still a slight lumpyness. Throttle is much better with no stammers.

jib

 

[Richard Moakes]

ETA repair article here http://v12uberalles.com/throttle_actuator_rewire.htm

 

[jibcl500]

Thanks for the link, interesting reading. One other thing I noticed whilst replacing the ETA, I had a look inside the inlet manifolds and noticed a lot of oil, mine is dry any ideas?

jib

 

[Richard Moakes]

This guy knows more about cl500's than anyone else I can find on the web.

http://pages.prodigy.net/jforgione/MB_S500.html

Nice article on the ETA as well http://pages.prodigy.net/jforgione/MB_asr.html

Not sure about the oil in the inlet manifolds, crankcase breather?

Richard

 

[jibcl500]

Yet another good link, spent most of this evening reading through it, some of the breather tubes look a little less air tight than they should be so sunday I will remove them and see if I can clean them and get them air tight. Failing that brick wall at 30 should fix it.

jib