Hi guys
I have a 2000 2.0T Forrester which started off as having a hesitation if you put your foot down sharply. Soo.... I spent the day doing..
1. Stripped off the top mount i/c
2. Stripped apart the throttle body and cleaned it thoroughly
3. The coil pack was also whipped off and cleaned and the terminals checked.
4. Also took the front Lambda sensor out*
OK, these are the notes from the above work
A: The IACV looks to have a cracked the inner part (inside the spring) as the actual plunger can be twisted round and pulled in and out.
B: The lamda sensor appears to be a Bosch 0 258 986 502, which I believe is a "generic" sensor. It looks like it was cross threaded when fitted as well. It was an !Removed! to undo as well!
C: a small pin hole was found in the vacuum hose from the intake to the "T" piece with the short section then off to the wastegate, so was replaced
D: The wastegate although very corroded seemed to be moving freely.
Now, put it all back together and hey presto, the car idles beautifully at 750rpm (it fluctuated a bit before). But, when blipping the throttle it now backfires. If you smoothly operate the throttle it doesn't.
What I have noticed though is that whatever I do under the bonnet, the wastegate doesn't seem to move at all.
I have a generic diagnostic tool, which I use on most cars, but this is giving me no help and says there are no error codes, although I know that isn't right as the EML has been on and I can force it on by unplugging something for example - so in other words, I have no diagnostic.
Last thing I have tried is disconnecting the Lambda sensor - it make no difference at all to anything.
My suspicions are
i. Front Lambda Sensor needs replacing with a correct one
ii, Coil pack is giving up
iii, I should have spent the day in the pub instead
iv. The IACV is knackered (but why would that cause a backfire)
v. I should have worked on my old Alfa instead today
Anyone got any thoughts?