mercedes211995

hi

recently i was given a c280 elegance 1995 done 117,000 kms. i have a carsoft diagnosis. i used to diagnose rough idle, it said the maf and lambda sensors. i replaced them and the idle was perfect, while i was driving it did not cut out, idle when cold was rough, but when warm was around 500-600.

now at neutral the idle is very rough when cold and when warm it is above 1000 rpm, but in gear around 700rpm.

so i hooked it up to my carsoft74 an this it said
10 Mass Air flow sensor
35 Lambda control is at rich stop: mixture too lean
66 Crankshaft position Sensor engine speed: implausible high
80 knock sensors 2 signal: open sensor
81 maximum retardation reached at least cylinder 1

i had the errors cleared yesterday before i read it today. i have cleared the errors will read it again tomorrow.

can anyone please help as how these errors appear within weeks of the parts being replaced?

can anything cause that error?

thanks for any help as i am desperate!!!

Plutoe

Although Carsoft sucks as a diagnostic tool----I would start by replacing the crank sensor and by the way you did put a new repeat new MAF in the car correct??

mercedes211995

you said new repeat? what do you mean by that?

i only replaced the MAF once, and i still got the error. as you the MAF here in Australia is very expensive. the cheapest i found was $350.

mercedes211995

FIXED IT.

hair line crack at the vacuum manifold vacuum manifold. also, the previous mechanic decided to swap the pins for the MAF, that is way it always faile.

superglued the crack, put the pins in their correct order and surprise surprise it works perfect. will drive it tomorrow to work with a big smile.

thanks everyone.