engine missfire

[raffles]

i have 1997 2,0l c class starts and drives perfect untill after about 20 miles and then i get an intermittant missfire it does not stall but jerks for a millisecond as i can just see the ignition warning lights go on and off idid 200 miles in it the other day and the fault is more off a nuisance than anything please helps ithink i can see a small light flash in the speedo as well

 

[roofless]

welcome raffles i would think it might be the cps-crankshaft position sensor on the way out but you might get some other idea's from other members http://www.detali.ru/cat/oem_mb2.as....418&VIN=*&CT=M&cat=19K&SID=15&SGR=075&SGN=04 it's No5 in this link

 

[raffles]

thanks roofless. i bought this car 3 weeks ago and have a reciept from 4 weeks ago for 127 pounds for the fitting of a new cps could be he had one fitted but problem remained.

 

[roofless]

we can only guess but it could be a few things so i would get a good merc independent garage to check it to save buying parts you dont need like coil packs..ht leads ect

 

[raffles]

thanks again roofless.ithink thats the road to go down no doubt.but first il check lead continuety distrib cap coil lead ect .pluss the reciept for cps looks a bit suspect its only a photocopy and not very proffesional think il check that out monday.as with these symptoms im still with you on the cps

 

[television]

Possible ignition switch faulty could cause this

 

[raffles]

thanx television. will have this checked out .it must be something simple as it has only done 45.000 from new.being new to merc cars do you think the symptoms i described are consistant to the cps

 

[jibcl500]

Have a look at the condition of the engine loom, if the insulation is cracked exposing the copper wire then there could be a short somewhere.

jib

 

[raffles]

thanx jib..will check that out as it does coinside with the symptoms described

 

[television]

It can be very hard to diagnose some faults in there early stages, when it does it you could try wriggling the key, but all of the reasons put up by others are all valid.

The CPS is a hard one as they usually fail when warm and OK when cold, but new faults come along all of the time

 

[raffles]

thanks for your time guys. had a new c.p.s. fitted today problem solved.thanks again 'raffles.