Russ323

My daughter has a 99' C230 Kompressor. It started throwing p0300 through p0304 misfire codes then started acting like it was starving for fuel while driving under a mild acceleration along with hard to get started then to the point of not staying started at all!
I have replaced the spark plugs and coil packs, fuel filter and pump and performed a fuel injector clean manually with each injector being cleaned while off of the car using the DIY 9volt battery and spray cleaner through each injector with no effect what so ever. The injectors were a little clogged, especially number 4.
I have cleaned the MAF and checked the fuel pressure regulator which shows no sign of a leak from the outlet.
Could the injectors simply be shot? And could anyone tell me the ohms resistance for the injectors so that I might check them for proper resistance.
The fuel pump I purchased was a little different than the one that came off of the car. It had an additional inlet beside the large inlet and the original didn't. I have simply plugged it with the old method fuel line plugged with a bolt and clamped shut. Is this the wrong fuel pump or is this fine?
Please help me as I'm at a loss as to what to do next!!!

cgshawaii

I'd investigate the fuel pump output pressure, sure sounds like not enough fuel to me, and not many other causes... 'cept possibly a bad fuel pressure regulator. Not closely familiar with the innards of these, more of a BMW guy m'self. Lotsa luck, but verify fuel pressure anyway, 'specially since you didn't use an "exact match" pump.

Russ323

I have good pressure. We replaced the injectors yesterday and that fixed the problem with not staying started. It still has a very rough idle and is throwing P0100 error codes. I have ordered a new factory MAF sensor. I seem to have somewhat solved the problem up to a point. I will update as soon as I have replaced the MAF sensor.
Thanks for the advise.

cgshawaii

A quick search for the P0100 code, which you did not explain, brings up the following: Before replacing the mass air flow sensor, try replacing the air filter and cleaning the air flow sensor with low compress air or mass air flow sensor cleaner. Reset code and drive vehicle. If the code comes back, it may be necessary to replaced the mass air flow sensor." This suggests the MAF still isn't right, but you have one on order. We hope this resolves your problem.

Read more: https://www.autocodes.com/p0100_mercedes-benz.html

Russ323

Problem is fixed !!! New MAF and cleaning the K40 relay connections did the trick!!!