A friend got this 2006 VW Polo with 1,2 BMD Engine.
After the MIL starting coming and the car did not run right he took it to the shop.
They changed Coils, Plugs, the Valves , Headgasket and Timing Chain.
But the problem is still present. No one could precisely say when the Problem
happens, you can drive it for 100km without one miss, you can fly 25km at WOT
at 4500 rpm with 150km/h over the Highway, no problems, but here and then it
just misfires on cylinder 2. Then you stop, cycle the Ignition and it runs again without
any problems, till it does it again.
I tryed all day and now i found out, it does ist repeating if you are at about 3800-4000rpm
for a few seconds, then it misfires....
I scoped what i thought could be it, but i don´t see a reason why it shuts of the injectors....
What should i scope out to get behind this Problem ? Or do you see something ??
Remove amp clamp from Injector and place it on common V or Earth for Coil(s) Primary and post the wave form.
And take a good look at the Valve Springs on Cylinder 2.
Thanks
Yes, I wanted to see what dropped out first, Coil, Injector or Compression. Unless you have a wiring fault then I agree - ECU.
Open it up and follow the pin back to the Driver/Mosfet and scope all three pins.
Got a used ECU for 20 Bucks....put it in, adapted it,
drove it, and Same error.....Even if it it used, the chance that
a second one has the exact same problem on the same Cylinder at the same
rpm Range, i don´t think is very likely.
Would there be a chance of seeing anything with the WPS500 in Cylinder,
without spark/fuel in the Cylinder at that RPM ?
And a compression test at Cranking speed is not realistic and doesn't reveal much. A dynamic compression would give it away WPS 500 in cylinder test as above would nail it.
I agree with STC. A cranking compression will only ever show a bad engine, never a good one. All to do with volumetric efficiency of the valve train relative to engine RPM.