PTSD
PMT
RSI
SAD
UDI
3 Likes
You look like a very sick man.
1 Like
Oh yes, but with an occasional sense of humour 
You seem to know your way around these engines so please can you explain IMRC, Intake Manifold Runner Control and how it works on the MK3 engine. I see there appear to be two purge type solenoid valves fitted which presumably reroute the inlet flow and it seems to be fitted to both 1.8 and 2.0 engine.
A simple explanation would be appreciated and why the revs changed from cold as per the original question.
Thank you
You omitted your S.T.D.
Sweet
Tea &
Donuts
2 Likes
Here is a link to a more informative thread that discusses the IMRC operation as it actually works on the MX5 engines.
Capitan Duratec, thank you for the contributions.
On a lighter note I hear that for your protection, Duratec now offer the MX5 MK3 1.8 engine in packs of three.
Aha, been wondering this myself since acquiring my very early, (55) 1.8 NC. There is a definite step at exactly 3500 rpm, hot or cold, though as others say, nice to get warmed before redlining! I’ve seen stuff about VVT or VVC systems and driven Honda VTECs but I also know the NC 1.8 doesn’t have this. I was wondering if it had reprofiled cams fitted but this thread clears it all up. The irony is that cold, damp weather makes it produce more power, just when you need it. LOL. All down to charge density of course, now of to fettle my carb balancers, (ask your Grandad)!
Many thanks
Marc
Interesting contris, very interesting subject, I think or afaik, that the Lamented Zetec engined ST 170 was amongst the 1st vehicle to use this inlet tecknology, with the ST using electrics and a cable which … at start up the engine pulls the cable on the inlet manifold to open the long inlets and at 5k rpm pulls it shut to the short ones… this solenoid sat tight against the bulk head rubber mounted and had a long cable reaching in around the side of the engine and was forever laying down, causing fault codes and higher fuel consumption… i had a work around on mine gave me more midrange torque and turned a car capable of on a good day 145 bhp into what they claimed 173 using a pushbike friction lever and cable pulling the flaps to mid position on both…it even sounded better induction wise… but to the other mazda/ford issues… When many Ford Rallye engines are being used with the same 2 LT unit thats causing so many issues on mk3’s and 4’s where has it all gone wrong…Neither Manufacturer made many engine faux pas in the past…LONG LIVE THE DIP STICK…W