jerking/misfire-190e
 

the car is a 190e- which has done 115,000 miles.

today i noticed a jerking/misfire while accelerating .

so far i had a new rotor ,distributor cap and spark plugs.

the fuel pump is a bit noisy.

any more ideas on what i should check/replace?

I think you just answered your own question, but I could be wrong. If the fuel pump is noisy, you should think about replacing it first. Low fuel pressure can cause a lot of strange problems.

xp

I think you need a new set of sparkplug cable.
Alex

A failing fuel pump certainly caused a miss on acceleration in my 190E. You might want to check the fuel filter first. You should change this anyway if you change the pump.

thanks for the input.

the filter was changed about 10,000 miles ago.


would a failing fuel pump cause an intermittent, unpredictable misfire?.

will also look to replace spark plug leads soon as these are the original ones are far as i am aware.

What kind of plugs?

Haasman

In my case, at idle, the engine was also intermittently misfiring, in addition to misfiring/jerking on accel.

New spark plug leads solved my issues.

If your car doesn't misfire at idle, it would seem more like a fuelling problem.

Cheers.

Definitely do the spark plug leads IMO, i'll bet my 999th post (this is it) that will solve your problems.

thanks for the further input and ideas.

this is why i like this forum-your feedback is very useful.

haasman,

the spark plugs are of the BERU brand -14k-7duo (which is the equivalent of bosch-h7dco).

azhari,

no misfire at idle-hence the fuel pump is a possibility as it is noisy on an intermittent basis.alos the jerking is intermittent-none of it recently-


:D :D

I'll go with those above who recommend spark plug wires. I had a similar misfire/jerking at low rpm's and idle and a new set of wires cleared it up. In my case, watching the engine around the spark plugs at night allowed me to see the occassional crossfire.

good luck.

andrew

i have done the darkness test to check the plug leads for arcing-could not confirm any sign of arcing.

but i am planning to change the leads as they are 115k miles old.

also planning to change the electric fuel pump,which is noisy at times and is also 115k miles old.;)

i finally changed the spark plug wires(leads) today.

so will check if jerking on acceleration stops.

hope this cures it.

if not, then the electric fuel pump will be next

good call. keep us posted.

andrew

My '91 190e 2.3 was doing the exact same thing. I replaced all the ignition components except the coil (because of cost $114)and that didn't help, then I finally replaced the coil last Sunday and it went away. It was sputtering and skipping pretty bad off the line and at idle before that, now there's no more. :)

positive feedback-

after changing the spark plug wires the jerking(hesitation) on acceleration has stopped.

i am also having the bosch fuel pump changed as it is excessively noisy at times.

thanks for the useful advice .:D :cool:

Good to hear the good news.

Cheers.

i had the fuel pump replaced today with a new bosch one from

the dealer but fitted by a friendly tech.

no more pump noise -

:D :D

Misfires after adding fuel injector cleaner
 

I am having a really difficult time with my 1986 Mercedes 190e...

I added the Injector Cleaner and about 7 gallons new premium gas, and drove about two miles, everything okay.

Then I go to start the car hours later, and boom...

rough start, misfires, car barely staying on.

finally i felt comfortable enough to drive home and the car would idle okay enough, so I headed home with about a 5-8 minute drive or like 3 miles... the car ran, but very choppy.

arrived home, turned the car off after a rough ride back. Started the car again, it fired right up, everything great. So I ran the car about 4 miles, just to try and blow anything out that may be causing problems. It ran great, just like normal.

Then, arrived home, turn car off, try and start again.. and Misfires again.

This is after about a thousand dollars of work already on the suspension. Why does this car hate me? What should I do? PLEASE HELP!

Back to the noise pump issue:

My '84 with a 2.3 was loud enough to hear it distinctly inside the car. When I would pull away from a stop, I'd get a little hint of power, then the power curve would gently back off. I could climb a hill with it, but it would be slow going. I replaced the gas filter first with no improvement, other than the fact that the OEM filter had some flow issues at 200K miles. Then, I gave up and replaced the fuel pump with a Bosch. What a difference, and no noise in the car anymore.

Not related, but a continuation: Replaced the OEM fuel distributor and EHA 4 months ago. The car will really scoot now, and idles... something that it never did before.

I look at the repairs I've done as better than a monthly car payment. I've spent a fair amount on it, but not nearly as much as I would have if these were monthly payments. It's a basically GOOD car, and simply needed to have some inferior repairs re-done correctly, and have some worn out parts replaced. I will drive this car anywhere now with no hesitations.