190e 2.0 engine occasionally missing a beat/running rough

[leicesterboy15]

Hello

I need some advice on my 190e, its a dificult one to explain. Basically, when I am driving along, sometimes you can feel the engine miss and it makes the car jerk slightly. You can also see the revs drop, then they immediately pick up again.

It appears as though there is an intermittent problem with the firing, its totally random, and normally happens when under normal load. When you put your foot down, it doesn't seem to do it as much.

I have replaced the plugs, cleaned the dizzy and have used petrol additive to clean the injectors. The injector cleaner seemed to make a difference very briefly but its now back (may just have been in my mind!).

I have been told that it could be something to do with the fuel pressure - when you are trundling along not as much pressure is needed so the fuel is not pumped as hard, then if the fuel filter is blocked slightly, the fuel does not flow as freely and the engine is starved of petrol - thus causing it to jerk or miss. It is intermittent because the dirt in the fuel filter doesn't always get in the way. Does this make sense or have I been given bad info??

I will replace the filter anyway because its only about a tenner and should hopefully not be that difficult to fit (or is it??). Has anyone seen this type of problem before or have any suggestions on how to fix??

Also, when I remove the petrol cap, I get a hissing sound. I have been told that on some cars this is normal, on others it means there is a fault. Does anyone know if its supposed to do this on a 190e?? is this related to the problem?

any help would be much appreciated!

Thanks in advance

Raks

 

[mike65]

The hissing sound is because the fuel system is pressurised and so quite normal to hear.

Mike.

 

[willydog]

sounds if your engine is misfiring! have you checked the HT leads?
probably worth changing if they are still the orignal ones and you have
done over 100K but do go for good quality ones as cheap HT leads don't last.

 

[mofo]

my 190e 1.8 does this also

i've changed the ht leads replaced the plugs, distributor and fuel filter still the same

to make things more complicated i noticed that it only happens when around 1500 rpm or below in any gear as soon as you can get past 2000rpm its fine.

sort of stutters along then blam away you go

will replace the coil next since its knackered the thing where the lead from the dizzy connects to, well i only have a third of it left and its arc a spark like a bitch so try that

 

[old230e]

Sorry but whats 'the dizzy ' ?

 

[mofo]

distributor

 

[simonben]

I had the same problem with my 1992 2.0 auto. But now it's moved on to difficulty starting and rough running on idle. I've been told it's the ignition module.