Friend bought a used VW Golf a few weeks ago, that now has a Misfire.
He called me because Engine was running bad ONLY at idle, but really fine
over 1500 rpm, On the Highway you would not think it had any problem.
But soon the MIL turned on, and his hope it only came from long standing time turned off
So we looked at the Scan-Data - ECU told us "Cyl. 2 Misfire detected".
We swapped the Coil from Cyl. 2 to Cyl. 1 and the plug from Cyl. 2 to Cyl. 3.
Erased the codes an stared it up.....a few Min later , same trouble Code.
So out with the Fuel rail, and swapped the Injector from Cyl. 2 > Cyl. 4.
And again, clear codes, start-up, wait a few moments and - "Cylinder 2 Misfire detected"
Then we picked the Pico, to see things we didn´t want to see
Relativ Compression with Sync on Cyl. 1 Coil showed it already
Then I did 2 In-Cylinder Pressure readings...the ECU and the Relative Compression were right.
Maybe one of you can see anything to narrow down the cause...
Why does Cyl. 1 (O.K) only draw 350mbar vacuum (after the compression peak)
and the bad Cyl. 2 with only 7,4bar compression draws about the double (about 600mbar) ?
Is there a clue to what is failing ?