Engine missing

[gina2201]

Gina

whilst you say it misses at 3500/4000 revs, will the car actually rev beyond that speed OK ie. will it rev OK at say 5000 revs ????????

Yes after that it will go ok and rev right through to red line.

The holding back at 3,500 revs issue feels similar to a valve bounce.

It also did it again from cold when I left work this afternoon, from 2nd to 3rd gear under acceleration, would sort of hold back and this wasn't near 3500 revs...poorly car!

Doesn't feel as pokey or sprightly as I think it should, unless I've got used to the acceleration now?

 

[lynall]

Got same prob on friends 2.0 bora, codes say misfire cyl 1 and 5 plus o2 sensor dead, clear codes and only the o2 sensor code came back up so i have got to order a new one for this weekend.

She says same as you misfire and feels dead, also says if it was an older car its almost like a big backfire would sort it out.

Still revs okay and fuel economy is still good.



Lynall

 

[gina2201]

Yes it still returns quite good MPG, approx 30mpg in my ever so accurate calculations.

Just want and would love to get it running spot on to be able to enjoy it and be happy with it!

 

[Dieselman]

Yes it still returns quite good MPG, approx 30mpg in my ever so accurate calculations.

24...

I still think this could be an HT issue caused by old connectors, or maybe a MAS fault, but I'd go for the HT side first.

By holding back do you mean fairly violent juddering.?

 

[gina2201]

24...

By holding back do you mean fairly violent juddering.?

Yeah, sounds about right!

 

[Dieselman]

If it's worse under load then I still think it's the HT lead connectors, as the plugs made it a bit better.

Get the lead parts from either an MB dealer, ECP or maybe nick_mercedes can supply.

ECP. 409220640 Ignition lead set. or alternative. 409220250 or 409220161

A cheap tool like THIS will find any ignition HT fault.

 

[evdok]

or http://www.justoffbase.co.uk/In-Line-Ht-Ignition-Tester-38898-Draper-1177

 

[rajinder_1]

or http://www.justoffbase.co.uk/In-Line-Ht-Ignition-Tester-38898-Draper-1177

Ha one of my customers!!!!!!

as for leads if you were able to get on star or some code checker you would be able to see where the misfire is coming from swap the leads and coil packs to see if the misfire moves woth the faulty lead......

my bet is stil the maf, i had a similar issue where the car would struggle around that same point until my cel came on and changed the maf was like a new car......

Raj

 

[lynall]

Serviced bora today only needs 4 tyres, discs, pads, cat, o2 sensor, alt belt, exhaust mounts, set of plug leads.

Lamp caused by the bodger billy that did some diagnostic work and repairs, ie new coil pack as he said that was the misfire, coil was replaced last year by me.

He has somehow managed to pull the wires out of the post cat sensor, break a plug lead, refitted a clip wrong, held the fuel filter on with a cable tie, nice!

I replaced the pre cat sensor last year for the mot and my head was right under the post cat sensor and there is no way i would have missed all the wires pulled out



Lynall

 

[Dieselman]

or http://www.justoffbase.co.uk/In-Line-Ht-Ignition-Tester-38898-Draper-1177

That device is no good for checking HT voltage, it will only say if there is some voltage present.
A coil or lead can produce reduced voltage which will work OK in general cruise situations but the spark will be too weak under load.

 

[gina2201]

I think I should just hand it over to someone to fix....! Just give it back when done!

 

[gina2201]

Ok, got some part numbers, coil packs: 0221 506 002 which I can find online fine but the leads/connectors are 0300 404 106 and put them into google and all I get is russian sites!

Replaced front brake pads today as the car was squeaking like mad......

.....still is...its the rears! So going to do them tomorrow too!

 

[gina2201]

Ok so today:

Replaced both coil packs - drives smoother but prob still there.

Replaced K&N air filter to standard one - problem still there albeit quieter now

Can give a little more info now on the problem; it is when you change gear then put the accelerator down and clutch engages is when it 'misses.' If you change gear and drive more sedate/power off problem does not occur. Took it for a spin on dual carriageway and also dropped the clutch in 5th, clutch on and missed again.

Any further ideas as I'm running out!

Car is getting hole in exhaust sorted tomorrow, could that really cause this issue? The hole is the in the pipe just before back box so pretty far back!

 

[Dieselman]

http://www.mbclub.co.uk/forums/showpost.php?p=755254&postcount=26

 

[gina2201]

http://www.mbclub.co.uk/forums/showpost.php?p=755254&postcount=26

I enquired about these (at GSF) - £25 each??!!! Or have I got the wrong part(s)?

Quite happy(ish!!) to fork out on them if it's the correct things!

ETA: ECP website just says "ERROR"

 

[gina2201]

GSF part number M92505 says Ignition lead set but are these simply just normal leads?

 

[Dieselman]

.....

 

[gina2201]

Changed Ignition lead set today, much much better but still seems to have slight miss from 2nd to 3rd gear on hard acceleration....but does it shift!!!

Could the holey exhaust be causing this lack of oomph?

 

[gina2201]

I've replaced;

• Spark plugs
• Coil packs
• Ignition leads
• Air filter
• Hole in exhaust patched up

Still has a misfire, (especially from cold) any other ideas?

 

[Chattonmill]

Silly question, but is it an auto?
Does it just feel dead for a couple of seconds?