1994 C220 Stalling Issue - PLEASE HELP ME!!

[Horologist]

Hi all
I'm new to the site and have joined in the hope someone can help me.
I own a C220 sport from1994 (W202) with automatic 4 speed box.
Issue :- sometimes, completely random times, the car will when slowing down to a stop or even just slowing down, she stalls.
Will start straight away afterwards but will continue to stall.
I was advised to clean the MAF sensor which I did using electronic component cleaning spray, when I do this (5 min job) it fixes it for a few days, even weeks but will eventually fail and start stalling again.
I eventually replaced the MAF and this solved it for a while but after a week or so, it all started again. I called out the AA and the guy said it could be the fuel relay sensor, so I ordered a new one and fitted it. I disconnected the battery to reset the car and all went fine for a while but yet again it still stalls when slowing or stopping.
If I take off the MAF and clean it using the spray it works fine again straight away. The AA bloke said that there was no fault with the engine and was puzzled by it. Hence why he said to replace the fuel relay sensor.

Does anyone know what may be wrong?
Anyone had the same issue?
How did you solve it?

The car has just 104,600 miles and has been very well taken care of. All wiring replaced and all hoses etc. Its very very clean and has many new parts.

Its so frustrating as I adore the car and wish to keep it but I don't want to throw any more money into it.
Has a private plate C20 MEC valued at £2000 and I managed to get the car and plate for half of that as my wife's friend (who's car it was) bought a SLK and wasn't using the C220 so sold it to me. Has factory AMG Bodykit and alloys and looks like a C36, suspension has even been lowered to make it look even more C36 like.

I don't want to part with it, I want to repair it as cheaply as possible.
Any tips.
Also / the coolant warning light is on from when I start it up (although only very dimly lit and eventually goes out)
Coolant levels are good and so wondering how to turn the damn thing off.

Any help would be greatly appreciated.
If anyone can solve my cars problems then I'll send you a voucher for a free watch service, which is worth around £750 depending on the watch you have. I specialise in Rolex watches but cover all other brands.

I'll watch this thread carefully.

 

[NW_Merc]

Get the fault codes read otherwise you'll be playing a very expensive guessing game.

 

[turbopete]

the running fault, and the coolant warning light coming on dimly makes me think you may have a bad earth somewhere between the engine and the body

 

[television]

The MAF could be out of spec, it is a hot wire on this one I think, some 202 cars have a OVP relay, but not all

 

[grober]

Clean the throttle plate edge and throat of the throttle assembly with that solvent spray. It gets dirty and tends to stick and this effects the idle. Sounds as if the cam cover vent is blowing a fair bit of oil vapour into the inlet pipe which is mucking up the throttle plate and Maff. You could try blocking off that inlet pipe and venting the camcover to a catchpot if that is the problem.

 

[Horologist]

Hi All - thanks for the help but I'm none the wiser.
Can you explain how I clean the part you said I need to clean?
How do I do it ? Can I so this myself?

Its getting to the point where I just want to leave the car at the side of the road.

The stalling usually happens on a warm engine, have changed MAF and Fuel Relay Sensor.
When car stalls, if I remove the MAF and spray it with electrical component spray, it will start and work fine for days and then it'll happen again.

PLEASE PLEASE PLEASE can someone tell me how I clean the part your saying I should clean, I'll try anything as I love the car and don't want to scrap it!!

Is there a YouTube page on how to clean it?

Thanks in advance

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[television]

How does it run with the MAF disconnected, was it a Bosch MAF

 

[NW_Merc]

Have the fault codes been read yet or not?

 

[Horologist]

It had a Bosche MAF fitted which looked new but replaced it anyway. Changed the fuel relay sensor too, stalled again today from a cold start, drove about 20 metres and then the revs drop when slowing and it stalls. Starts again straight away but will stall again when I slow down. If I spray the MAF sensor with electrical cleaner it works fine for a while.
I'm thinking tomorrow that I will clean the thing (name escapes me) that the air filter - MAF sensor and such like lead too (where the throttle is) as I hear these get gunked up.

After changing the MAF and Fuel relay / should I disconnect the battery so the ECU resets itself or not to bother.
The engine is spotless and the AA man said that it most definitely isn't an engine fault bug sounds like a fuel issue.
Nearly always stalls after a refuel, dunno if that's any help!!!

I love the car but don't want to throw money at it.

I'm considering breaking it, AMG kit, alloys, number plate. Engine & gearbox are great.

Would love to repair it, so will clean the fuel/throttle thing tomorrow to see if that makes a difference.

Fuel consumption is good - better than it was before I changed the MAF over, MAF is not Bosche but is made by the same company that make these for Bosche (has same name on it)

If anyone can instruct me on how best to clean the bits I need to clean what I need too with what few tools I have!!!

The car has had new hoses, all wiring re done - just look yourself - its spotless

Thanks guys

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[Horologist]

Runs with MAF disconnected but is sloppy


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[Horologist]

Can't afford the £55 diagnostic check

I know this would save me a few quid in the long run, but am in ESA and just can't afford to have it done. Can only just afford to run it!


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[grober]

Right---- unclip the top of the airfilter box on the driver side/ disconnect the MAFFplug/ remove the air temperature sensor on the rear side of the black plastic cross engine air intake rectangular pipe/ remove-disconnect the cam cover breather pipe / slacken the large circular jubilee clip holding the plastic inlet pipe to the cast alloy inlet manifold via a large bore rubber connector pipe- then remove the cross engine inlet pipe- its held on with rubber mounts -usually just slip sideways- try not to break anything--- this will expose the throttle body innards mounted on the manifold- gently!!!! open the throttle plate with your fingers and clean the throat and edge of the plate with solvent-- reverse the process making sure there are no leaks- touch of lube WD 40 Helps rubber slip on easy

 

[grahamcol]

OP don't scrap it ! You mentioned earlier that the MAF wasn't a Bosch unit but made by someone for Bosch. Doesn't sound good to me. If it doesn't stall when the MAF is disconnected (I know you said it's rough like that), I'd be inclined to think your stalling issue may be down to the MAF. I'm not an expert on this but do believe "spurious" MAF's can cause lots of problems.
Good luck with it.

 

[Alex Crow]

Two thoughts...

Is the throttle return spring broken?
This spring does break on this car, and if the idle microswitch is not being operated (spring returns throttle mechanism to close microswitch) you will have these symptoms.

Second thought, a wiring issue at the MAF sensor.
Now, you say the wiring has been changed - can you elaborate on this please?
On this car, engine wiring looms were prone to failure of the wiring insulation. This can happen to the wiring to the MAF sensor, and possibly explains how the car runs better after the wiring has been moved (as you will be doing when cleaning the MAF sensor).

Unless the MAF sensor gets very oily, I doubt the physical act of cleaning it is having any effect at all.
Also, repeatedly cleaning it will eventually damage the film inside.

EDIT: if it is not a Bosch MAF sensor, it needs to be - Bosch make them for Bosch, no one else.

 

[Horologist]

I today cleaned the fuel thingy that was advised to clean and boy was it filthy, so dirty in fact that it stopped the circular thing that opens when you open the throttle from closing properly.
After removing the unit as advised, I broke a hose that connects directly to the engine, although managed to fix this with some hose tape, once I'd cleaned it, turned it over and it started without even having to press the throttle. Have driven about 20 miles since my repair and not only does it seem to idle properly now but the car is so much more responsive.
I think I've sorted it now (touch wood) but only time will tell I guess.
I do love the car and really don't want to get rid of it but was offered a 52 plate C220 CDi coupe for it yesterday.
Slightly more miles than mine and also has a 6 speed manual gearbox, which puts me off as I hear the manual boxes on Merc's are not the best! Its not taxed either, so £95 for 6 months tax. Had my C36 lookalike up at £950 and I think that a 52 plate C220 CDi coupe would sell easier than my old W202 model.

Someone asked me to elaborate on wiring, all I can say is that it appears all wiring has been replaced (will add picture)
I know the harness decomposes at 100k so maybe this is why it was all done, I don't know as bought it this way. 95% of the hoses have been replaced too.

Thanks for everyone's help - much appreciated

One more question - the car has a private plate C20 MEC and have receipt for the purchase (£500 in 1995) but have since had it valued at more than the car. My V5 is a V5C, does this mean I can take the plate off the car and sell it and put car back on an L plate?
Anyone know how to go about doing this and if so, is it a lengthy process?
Or would I have to sell the whole car with the plate on it?

If I could get a grand for the plate (valued at £2k by regfinder) I'd be over the moon as then I could afford the £325 for a full service on the car and £55 for diagnostic check.

Any help on this matter would be much appreciated

Thanks in advance

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[Horologist]

I still have the original Bosch MAF in the boot, looks like new and so would it be advisable to put the Bosch one back on?

Thanks again for all the help - has saved me a fortune in garage fees as Mercedes charge around £120 per hour just for labour.

Long live my C220 Sport

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[television]

You can take off the plate and get the original number back on the car, you can put the number you take off on retention, you have to do this while it is still registered in your name, you are then free to sell it, all the details are on the DVLA web site

Pleased its going OK, do put the Bosch MAF back on if the new one is not a Bosch

 

[turbopete]

I do love the car and really don't want to get rid of it but was offered a 52 plate C220 CDi coupe for it yesterday.
Slightly more miles than mine and also has a 6 speed manual gearbox, which puts me off as I hear the manual boxes on Merc's are not the best!

theyre not the slickest out there, but theres certainly nothing wrong with them! they just take a little getting used to! (im on my 4th MB, 3rd with Manual 'box and between them all, the Manual ones have covered a total of about 190k miles between them whilst in the ownership of the family)

 

[grober]

Your old W202 is a far more solidly built car and easier to repair than the later W203. High mileage turbo diesels can be very problematic and expensive to repair = injectors-injector pump -turbo etc. The M111 engine in the W202 is very long lived. I would be inclined to hang on to the older car- better the evil you know.

 

[Horologist]

True - and I think my car is much better looking!

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