Ok, so trying my third forum for some help.
Starting to get rather desperate.
A long thread for those that need something to read on Seloc here:
Now the short summary.
Bought a S2 111S in october last year, car was acting up on idle and jerking a bit which I noticed only after the deal had been made. Took undertrays off and found oil - fast forward - engine was rebuilt (piston rings were not sealing) here in Sweden by a shop that supposedly knows the most about Lotus K and older.
While rebuilding it was also noticed head was ported. Did not know this before and managed to located last owner in UK that confirm port as K06A port of Dave Andrews which runs on stock ECU.
After engine rebuild, the idle is still unstable (it sits fine for a few seconds then drops, then hunts back up and so on). And also at lower revs car is dropping revs. For example, if I go to the throttle body and rev it by hand to avoid issues with cable .etc and keep it steady at say 2500 rpm, it will drop down to around 1200, then hunts back up o 2500 this is repeated in a steady pattern. Looking at short term fuel trim in such a cycle shows it drops to -30 then back up to ~-5 then down and up again in repeated cycles (graphs in Seloc thread). This is felt as jerks at cruising speeds when driving.
On higher revs the car runs amazingly and pulls hard to the rev limiter.
The guy that rebuilt the engine has asked everyone he knows without any new ideas. Now he said it might be that stock ECU can't handle the port. But last UK owner and Dave Andrews say it should run fine on stock ECU.
Here a list of things that have been tried:
- different diagnos tools have been used, "misfire detected" has been shown on some, but no fault code is presented
- new ignition coils and leads
- new spark plugs
- new fuel filter
- new IACV valve
- new TPS sensor, different MAP sensor tried + brown ECU coolant sensor
- throttle closes correctly and opens fully according to ODB
- Emission test was made and passed with good emission values so Lambdas seem to work
- 3 different 111S ECUs have been tried to ensure no ECU issue
- lots of cables jiggled to ensure it is not a broken cable issue anywhere
Unfortunately there are few shops that even would consider to take on a Lotus here in Sweden, even fewer that know what they do, and they are far far apart, Current shop considered among the best is 40 miles away. At this point I feel like pouring a can of gasoline on the car....the more sensible alternative would be to actually take a few days off and drive the car to the UK, but recently had a baby so not an option right now :/