Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi, the distributor caps and rotors are notorious for causing misfires on this model. If you have not replaced the caps and rotors yet I would remove and inspect them. Most likely you will find traces of spark arcing inside the caps.
Please let me know if you have any questions.
caps and rotors are new
Ok, can you describe the symptoms?
first had mis fire once in a while noticed injector harnes was bad and replaced it
no difference ..... changed plugs and wires
noticed throttle body wiring was bad replaced throttle body
car will start idle fine for about 3 min
and sometimes die if you raise the idle it will break up very bad then die
tgen hard to restart
It sounds like an ignition fault but have you checked the fuel pressure?
yes about 45 if i remember
Ok, have you substituted new coils?
no ihave not
If it's breaking up under load I'd have to try a new coil. You could swap one and if it doesn't help reinstall that one and swap the other. If you can identify the misfiring cylinders you may be able to trace the miss back to one coil. If all of the missing cylinders are in the same cap I'd replace that coil.
I assume that the entire engine harness has been checked or replaced.
95 was a bad year for the harnesses.
only the upper
Ok, but you bought the complete harness, correct?
comlete upper for injectors from the computer
Ok, if the harness is good I'd have to try a new coil or two and then I'd suspect the ignition module.
You should also make sure that you have good voltage going to the coils.
let me check the coils tomorrow voltage should be 12v
Yes, approximately battery voltage.
are modules and coils common
Coils are fairly common. The module can fail on only 1/2 and give you spark from only one coil.
Let me know if you need anything. I'll be around in the afternoon tomorrow.
You're quite welcome.
If you would please remember to rate my service tonight I would appreciate it. You can still reply back if you need further assistance after you rate my service.
replaced colils and no difference
will run smootthe at idle raise the idle it starts to break up then cuts right off this all happens within a minute