flathead

I have a 2002 kompressor that runs fine unless I get aggressive with the throttle. About the time things start to get fun the engine will hesitate and start missing on at least one cylinder. Its a very regular dead miss, as if a plug wire has been removed. Turn the engine off and re-fire and its fine again. Almost seems like a limp mode. All that I have checked so far is the air cleaner and it's filthy. I suspect the fuel filter may be the same. Is this by chance a common problem with a "Oh thats simple, your widgit is broke" type of solution?

aquinob

No quick or simple fix. From what I'm reading between the lines, it sounds like routine maintenance has been put off. How many miles on the car, do you run it on premium or regular?

I would suspect ignition or electronics first off if it's a problem that seems to reset itself after restart. Have you checked for codes? How are the plugs and wires? Start with some basic troubleshooting steps and you can narrow down where the problem might be.

flathead

Code is p0410. Secondary air. Check valve rusted in two. Could this cause the limp mode and poor performance?

aquinob

Not sure. I googled and found some info. Secondary air comes from that electric pump that runs when the engine is cold and injects air into the exhaust manifold to heat it up quicker and keep the cats from getting gunked up with the initial cold exhaust.

If you are leaking exhaust out the check valves that may affect back pressure which will affect how the engine runs, but in my mind I cant make that connection. In any event you need to replace the check valve or you will always have the code. Hopefully the pump still works, that is an expensive little item. Intake manifold leaks are where you run into vacuum problems.

flathead

Thanks Aquinob, from what I understand on the c230 kompressor the secondary air uses the supercharger for the air pump. After the engine is warm the actuating valve shuts off the secondary air. That being the case I cant see why a bad check valve would affect the performance. Maybe it is a back pressure thing or o2 sensor getting wacked out becuase of it. If I'm gentle I can get the rpm's up past 3500. but if I firewall it, it will cough at about 3500 and go into limp. I am certainly replacing the check valve, just don't expect it to fix the performance issue.

aquinob

OK, didnt know about the supercharger doing double duty, but it makes sense. I'm with you, dont really see how it could affect one cylinder but at this stage of the game I'd replace it and see what happens. Have you put a vacuum pump on it while its running to see where that is? The MAF tends to cause lots of funky problems on these cars as well. Like it or not, they are heavily computer controlled and most of that functionality is not accessible via odb2. Best you or I can do without the specialized MB diagnostics is basic troubleshooting looking at vac lines, ignition modules and wires, etc. Have you pulled plugs yet? One badly fouled plug could tell you a lot if there is one cylinder not pulling its weight.
HTH, Bob.

RobertG

+1

You might want to start with a tune up.

flathead

Changed check valve, fuel filter, found vac line off. No more po410, but got cam sensor code. Wires about to fall off cam sensor. Fixed that also but still pops and misses at about 3500 rpm (at wot) and goes to limp. I think I'll do like you guys say. Check and change plugs and wires and send it to the dealership.

flathead

I just got the car and dont really know how it is suppose to run. It really jumps out of its paint before it starts missing. Do they run that good or is it possible its over boosting? The missing starts with a lean sounding popping.