Intermittent Hesitant Engine / Cutting Out When Warm?
 

Right - not as straight forward as it may sound:

I have an NB, supercharged, no air flow meter with Adaptronic ECU. Normally goes perfect etc.

A few days ago it started bouncing / kangarooing / spluttering when driving. Very, very jerky. Cuts out at traffic lights. Needs feathering of throttle to keep it from cutting out. Very jerky on take off. Keep your leg at constant throttle and the revs will respond a second or so later and rev up then drop / up then drop.

Then 10 mins later it behaves perfectly again. Try it in the morning when cold, all is well until it comes to temp and it starts all over again.

I have changed the Cam angle sensor for the newer NB8A type which initially seemed to cure it as it drove better. Tried starting it 10 mins later and it would idle like crap again - it would cut out etc. Fuel pressure was tested - no issues.

Started it again tonight, perfect until it warmed up then jumping / kicking and surging again for 15 mins then all was well.

I have simply no idea apart from the fact that the new cam sensor may have thrown the Adaptronic tuning out? This is the only thing that it could be according to my MX5 specialist although he thought the cam sensor cured the jerking problem, just not the idle problem - I haven't spoken to him yet that it feels exactly the same as before I bought it to him as he's off on a few days holidays.

Any ideas?

Adaptronic?

Crank sensor?

Throttle position sensor?

Any help would be appreciated.

Bump

Subscribed. Having similar issues but when cold as well. Need to figure it out ASAP, also maybe help the OP ;)

You have the capability, datalog it and look for drops. I had that happen once and it turned out to be a map sensor on its way out. The sensor would stop reading and the ECU would adapt by going to default MAP value (35kpa?) which would cause all sorts of havoc.