cant figure out why it's missing - PeachParts Mercedes-Benz Forum

opossum · #1 05-15-2003, 12:05 AM

Hello all,
It's an 89 190e with the 2.6...Generally, when this has happened in the past it was just a fouled plug. Well, I fixed the prob with why the plugs were fouling in the first place, I quit burning oil. I don't foul plugs anymore but have new ones in there anyway. I have spark in all wires, New cap and rotor, just changed the fuel filter and it still runs rough and gutless as if it has a fouled plug.

any ideas?

Freestyler · #2 05-15-2003, 03:45 AM

Did you inspect the ignition coil?

On my 300E the contact point (copper "cup" where the wire makes contact), was corroded to nothing more than green powder. -Strangely enough it still started fine but had very rough idle.

Freestyler

sbourg · #3 05-15-2003, 10:24 AM

Which plugs? What electrode gap?

Steve

haasman · #4 05-15-2003, 10:45 AM

opossum

If it were my car at this point I would run two bottles of Techron Fuel Injector cleaner through it with less than a full tank of fuel. I would get hot and drive it hard, say in the hills.

If that didn't clear it up I would bleed the fuel injector lines at the fuel distributor. A dangerous job >raw fuel on a running engine< but often on older cars seems to help.

I did the above on the 190E which ran so poorly I was sure it had severe internal problems. When I bled the injector lines I was amazed at the amount of crud that came out. I did it several times.

The 190E now runs very well, lots of power and almost a perfect idle.

Keep us posted,

Haasman

opossum · #5 05-15-2003, 04:40 PM

steve- bosch coppers at .032.. same as I always have..h9dc I think

freestyler- I will go check the coil wire for crud.

haasman_I will also go pick up another bottle of injector cleaner and see what happens...If that is it I have a testimony for using chevron gas because as of lately my wife has been using the stuff from costco because gas has been so expensive everywhere..I warned her..

opossum · #6 05-15-2003, 06:06 PM

I threw in a big bottle of techron (for 20 gal) on 3/4 tank which had previously had some octane boost / injector cleaner by stp. I drove around town pretty hard for 45 minutes... I already can tell a little difference so maybe it is just the injectors.

My new question is: Is it bad to drive around like this when you arent totally sure what the problem is? Like if you had a fouled plug and drove on it, all that gas is accumulating in your cylinder unburned..obviously that cant be that good for your cylinder walls and rings, right?
thanks again all!

opossum · #7 05-16-2003, 10:26 AM

just a bump

haasman · #8 05-16-2003, 10:53 AM

opossum,

Probably not but it depends on what is wrong. Do you have raw fuel leaking into a cylinder? Are there loud and unusual mechanical noises? Are you experiencing very low MPG? Unusual oil consumption?

I think injector clogging is more prevelent than a lot of people realize. Most drivers in America take it easy, don't do sustained high engine speed driving. Fuel quality varies a lot and some people don't see the value in running the right octane.

The 300E will run poorly and stumble when warm and eventually also with cold starts when I have done the injector cleaning in a long while. This car has 207k miles and has never had the injectors replaced ....

How is it running now?

Haasman

opossum · #9 05-16-2003, 12:05 PM

still pretty rough at idle and sluggish. How would I telll if raw fuel was building up in a cylinder? It isn't excessively noisy..maybe a ticking valve noise at most. Too soon to tell if I'm using excessive oil or gas. However, a friend of mine looked at it and is convinced that all the plugs are firing. I just wish I had access to a spare set of plug wires (I'd hate to spend 125 bucks if I didn't have to) I'm hoping the injector cleaner will clear things up over the weekend. If not I'll probably just order some plug wires anyway.
thanks again, opossum

opossum · #10 05-18-2003, 04:08 PM

As it turns out, all the plug wires are indeed ok. There is not alot of marked improvement in terms of an injector clearing up. Is there a chance the the timing advance is stuck? How do I check for that? Is it a vacuum line?
thanks again everyone

UKEvo · #11 05-18-2003, 06:24 PM

Have you tried checking the duty cycle? Do a search in the archives..

xp190 · #12 05-18-2003, 07:08 PM

I had an occasional miss on my 190E, and it was a bad wire, easy to spot in the dark, actually it was 2 bad wires

xp

opossum · #13 05-18-2003, 07:59 PM

Hmm,
what the heck is a duty cycle? Does it have something to do with the mixture? I've only heard of duty cycle in reference to welders..LOL! I did a search but there was nothing informative for the "fixing your car for dummies" type guy.
thanks again.
xp190, How did you tell that your wires were bad in the dark?

opossum · #14 05-24-2003, 11:30 AM

Well,
I figured it out, there is no compression in #6. Valve job time? I just did the valve seals 2000 miles ago..should have done the whole thing, eh?
thanks all