Well it's not good news for the QingQing, she is still fairly poorly and it is looking more and more like something terminal in the engine. She broke down the other day with horrendous backfiring. Getting fairly depressed now...
So story so far:
- Head gasket went in the summer.
- Head gasket replaced - poor running afterwards (rough idle, stalling, strange carburettor behaviour, hesitant throttle and what seemed to be occasionally firing out the intake side!)
- New carburettor was fitted and this improved the idle and pickup a bit
- Engine still running rough with slightly erratic revs
- Fitted a spare dizzy I had (which I know is a good one as it came off Chichi) and she ran a bit better.
- After a trip to Essex and back, she started to stall at idle and backfiring slowly developed. Got home but eventually it broke down on the way to work a following day.
- Checked compression and this was fine
- Checked valve clearances and some of these had tightened up by a little bit so re-set to 0,15 and 0,2 (inlet and exhaust respectively)
- Engine ran better then but still not perfect so fitted electronic ignition unit and it ran beautifully. Smooth steady revs.
- Drove it down to somerset and back...all seemed ok but took it very easy. Then a following day drove it a short trip and started to backfire again and also stall at idle.
- Also noticed an oil leak develop - from somewhere around oil filter / dip stick. I think this is just an annoying co-incidence but never know.
- I've re-checked valve clearances today and they are still fine so it's not burning out the valves like I had thought at first.
- Doesn't appear to be much slack in the timing chain but without inspecting it by removing timing chain cover etc (a tricky / impossible job in the car) I won't be sure.
I am now stuck in a situation which feels terminal... All I can think I can do now is take the head off and check for something like cracks or slight leak on the head gasket perhaps. But this engine shouldn't need a full re-build at 50k...they are solid engines usually only let down by their Dizzy or Carb!
Has by any chance anyone had a similar story? In particular the missfire issue and if so what caused it? I am really out of ideas now...and more importantly out of parts!!
Thanks in advance for any suggestions.
Cheers,
Si