C220 Starting Problem
 

I've been dealing with this issue since the head gasket and wiring harness job last fall. The head gasket was replaced and so was the wiring harness.

Since then, the car would die sometimes right after starting. And sometimes its fine. But once its running it never dies. I've cleaned the MAF already but I don't think that's the problem anyway. I have disconnected the MAF and the symptoms don't change. Also, MAF issues usually exhibit themselves when the car is running - not starting.

I'm wondering if there is a disconnected vacuum line somewhere that may be causing this. But which system might it be associated with?

Any thoughts?:confused:

Have you tried scrubbing out the throttle & butterfly?

Has the fuel pressure been checked for bleed-off?

Thanks mbdoc.

I remember cleaning the throttle body once after the work. I'll try doing it again.

As to the fuel pressure, how do you check it?


Also, not sure if this has anything to do with this but I can hear the fuel pump when the car is running. But this has been like that since I got the car 75k miles ago. The starting problem only started after the head and harness job. I ahve checked all the connections of the harness and they appear to be all in place and tight.

I traced all the vacuum lines in the engine compartment and found one line going to the fuel pressure controller leaking. I replaced the line but that did not fix it. I thought for sure that was it. But for sure, my transmission is shifting like a charm now.

i believe The key to the answer of this starting problem has to do with why the engine does not die once you give it gas after starting. Something is telling the engine that its getting what it needs so everything is ok now and I'll continue running.

Could it really be just a bad MAF sensor?

any ideas anyone. i read a test procedure for a Pierburg MAF but a bit tough to do it on a bosch since mine is a round connector. can anyone help on how to test Bosch maf for a W202?

Tobybul,, did you find out what problem? My 95 C220 seems same problem as yours. Just did wiring harness, head gasket replaced and fuel pressure regulator. Now, that car is very hard to start when the engine is warm. Cold start -- no problem at all. After driving until engine warmed up..... Turn it off and can start right up again. If wait about 5 to 10 mins, then it is hard start. After start it, still feel little shaking. *** New Bosch MAF was replaced about 3 months ago (before head gasket replaced).

Some more information, that guy helps me to replace head gasket. He put the wrong wiring on the airpump and causes 40A fuse burn when cold start. Also, put the ignition wires into wrong position for the coil. Those I fixed it up!!! I want to know that will oxygen sensor and throttle body can affect on starting!!!

Quick little updated! I parked that C220 over one year for dealing the hard hot start problem. The previous mechanic did the poor job on head gasket replacement. Two days ago, I found out the timing is off one teeth on the intake camshaft gear. Will it bent valve if off one teeth timing? Anyone can give me some hints for re-align the timing chain? I really want to get it running again before summer coming. Thanks