On my 2004 S430,

There is so much fuel dumping in Cyl 2 it is locking the motor up upon starting.

I'm assuming the injector is bad but I would like to rule out the computer.

The confusing part that I have is I see mis fire codes for cyl 1 & 2 & 3. Now can a bad injector cause mis fires in other cyls? Maybe a build up of fuel in the manifold can leak in to other runners?

Can the SDS help diagnose a bad computer? If so how?

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1999 SL500
2003 C32
2002 S55
2004 S430
2003 E320
2004 E500

I would clear the codes and see if anything comes back up on those cylinders. Can you swap #2 injector with one on another cylinder and see if the issue goes to another cylinder? My experience with a bad computer is that the diagnostics won't communicate with it.

__________________
Jim

I don't want to keep locking up the motor. I will use that idea with the rail detached and see what I come up with. Thanks.

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1999 SL500
2003 C32
2002 S55
2004 S430
2003 E320
2004 E500

This isn't rocket science! the injector on cyl 2 is stuck open and depleting all fuel pressure at the end of the rail which in turn causes misfire on the surrounding cylinders.

__________________
600SEL '91
300E 4Matic '88
240D '83
280SE '77
350SE '73
The most complex systems can fail in the simplest way.
Contra verbosus noli contendere verbis, sermo datur cunctis, animi sapientia paucis.

i don't believe in the lord! He's never bought me a Mercedes Benz.

The engine control module can only trim fuel on an entire cylinder bank. It can't adjust individual cylinders. It sounds like the #2 injector is hung open. Also, don't forget about the O2 sensor code. That may be the cause of the other misfire codes.

well rockets do inject fuel

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1999 SL500
2003 C32
2002 S55
2004 S430
2003 E320
2004 E500

I took an injector off the sl500 that had the same flow and ohms, problem solved for now.

__________________
1999 SL500
2003 C32
2002 S55
2004 S430
2003 E320
2004 E500

Clear the codes and see if anything pops back up.

__________________
Jim

New codes



I tested sensor B1S1 and B2S1 and they are with in range at idle.



I tested the Oxy sensor after the cats, the right side which is where I had the bad injector was showing very little activity, and the left side was alittle high out of range.



I find it odd that I'm getting before cat oxy sensor codes and seeing a bad after cat sensor code. I don't think I melted that cat because the car seems to run very well. What do you all think about these readings?

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1999 SL500
2003 C32
2002 S55
2004 S430
2003 E320
2004 E500

I think all the oxy sensor codes coming up after the fix was from all the unburned fuel left in the system. I have put 100miles on the car so far with out any more codes. I did notice the Oxy sensor and cat monitor has not set, does any one know what the computer is looking for to set these 2 monitors?

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1999 SL500
2003 C32
2002 S55
2004 S430
2003 E320
2004 E500

do not forget to check the oil for gas contamination I had to change the oil when it happened to our 190E JNT