merc 114 280ce with M 110981 engine

Hi,

My name is Jan Fritz, from Pretoria South Africa.

I have a 280CE that I cannot figure out. It start very easy hot or cold. Engine will rev freely up, however if you want to drive it the engine loose all power and at times bacfire severely through the intake. I have checked the fuel pressure on idle and when revving engine, and it remains at 2 bar. I have checked the MAP sensor and the ohm readings OK. Can somebody please point me in a direction as I am now like a moth around a flame.

Hi Fritz,

welcome to you here. We did not yet have many SOuth African active participants here.

Well everything starts with engine mechanics and ignition, as you can read in my checklist . So you need to measure compression, adjust valve play and verify ingition dwell and timing at 3000, 1500 and idle rpm and vacuum adjustment before it makes any sense that you search errors in D-Jetronic. Have you done so?

The backfiring you describe can well be a wrong ignition timing. As I cannot link to a freely available page in English for 280 CE, I write those values here:

Ignition distributor: 0 231 306 002 (label on side)

Dwell : 34-40°

Adjust timing to
32° before TDC @ 3000/min without vacuum

Verify
14°-19° @ 1500/min without vacuum
0°+/-2° at idle with vacuum

Unfortunately normal workshop manuals of Strich8 model do not cover the 280 E/CE engine. Also Bosch did not publish an English version of their workshop manual yet. That makes life a bit difficult for you.

If engine mechanics and ignition are well, then we will look into your D-Jetronic together.

Thank you very much for your response. I have checked the fuel pressure on idle and at about 3000 RPM and it checked out fine. This was where I made the old common mistake of assume. Although it is a new non genuine fuel pump, I never checked the pressure under load. This came down to 1.5 bar when driving and under load. This is why it lost power and started to backfire through the intake as the mixture was too lean .
I am actually ashamed to admit that I trusted the pump and turned to the forum, however I am not sorry for joining the old timer site.

Hi Fritz,
take this pump: jetronic.org/de/forum2/jetronic/433-test...mmending-a-fuel-pump

Regards
Norbert

Hi Fritz,

you are welcome. You can also use Bosch 0 580 464 013 pump.