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-   -   1989 190e 2.6 - Runs Rough (http://www.peachparts.com/shopforum/tech-help/151085-1989-190e-2-6-runs-rough.html)

Hominid 04-19-2006 02:28 AM

1989 190e 2.6 - Runs Rough
 
Hi, folks -

I'm new to Mercedes, and of course to the board.

What a great resource! Thanks in advance. :)

So, here goes:

The car starts easy enough, but it idles like it's missing on a cylinder or two. However, it smells like it's flooding. If I run the RPM's up to 3500-4000, it seems to smooth out, but only a bit. Once I let off the gas, it returns to the sputtering/flooding routine. It will usually run for a couple of minutes like this and stall, so I'm not sure if it's getting warm enough to change the circumstances (such as I've read in other posts). It starts right back up. Oh, and I'm in a desert climate in Phoenix.

After searching and reading a ton in the forums, I have checked the fuse on the OVP (good) as it was jumped (the battery now will start it). We sprayed around looking for vacuum leaks (didn't find any).

One thing that struck me as odd is that the air filter cover has no nuts. The screws are there, though. I'll be getting some wing nuts soon. Probably nothing, but I thought I would mention it.

I'm looking for suggestions as to where to go from here. I have the 201 manual that I got from Manuals Unlimited.

Thanks!
-Joel

Hominid 04-20-2006 02:22 AM

Bump.

Anyone? Bueller?

gmercoleza 04-20-2006 03:52 AM

I would start with the basics. Since it is misfiring, the secondary ignition should be checked out. How old are cap/rotor/wires/plugs and are they correct (i.e. non-resistor and NOT Bosch Platinum)? Did you inspect them?

Oz 300te 04-20-2006 06:22 AM

I'll have a go, I'm new to mercedes but have a fair bit of knowledge on other cars.
If it smells rich then I would check your fuel pressure, if the regulator isn't working properly it could be supplying to much pressure to your injectors, causing it to run rich.
Or you could have injectors that are just stuck open, unlikely though.
You need to do a compression check first. Then go from there. If the comps are good then you can start to do some fault finding.
good luck,
Grant.

mctwin2kman 04-20-2006 08:27 AM

Check plugs, wires, rotor, cap, O2 sensor. Once they are verified to be in working order we look for vacuum leaks, cracked rubber dry rotted vacuum connectors leak liek crazy. Then check the Air/Fuel Mixture using pin 3 on the X11 connector. Once all is in order then we will move on if you still have issues.

gmercoleza 04-20-2006 10:00 AM

Quote:

Originally Posted by Oz 300te
I'll have a go, I'm new to mercedes but have a fair bit of knowledge on other cars.
If it smells rich then I would check your fuel pressure, if the regulator isn't working properly it could be supplying to much pressure to your injectors, causing it to run rich.
Or you could have injectors that are just stuck open, unlikely though.
You need to do a compression check first. Then go from there. If the comps are good then you can start to do some fault finding.
good luck,
Grant.

Mercedes has CIS, this is not your standard multipoint fuel injection, it is a recirculating system that is always injecting. Pressure problems tend to be weaker pressure rather than higher pressure (I'm not sure how higher pressure would be achieved). The gas smell is likely from unburned fuel exiting the tailpipe - it is after all misfiring. The HC reading is probably way up there.

Again, I would first check the cap/rotor/wires/plugs and go from there. Vacuum leaks would be my next check...

Hominid 04-20-2006 11:42 AM

I appreciate the input.

I'm towing it home this weekend from my partners shop so I can spend time on it whenever I want instead of having to make the time to go down there.

I'll keep you posted, and I'm sure I'll have more questions.

Thanks, all!
-Joel


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