Just of recent, I was sitting at the lights, smooth idle as norm, when engine decided to have a slight mermer for a split second (dropping revs approx 1 or 200rpm), but quickly picking itself back up to norm again.
 
Driving from there onwards felt a little laggy - slightly down on power & was ever so slighly missing, not under load though. 
The next day, it progressively became worse.  Now on idle, its idling very low (500rpm) & sounds like I have a 3 quarter race cam in it. 
 
If I try to rev it quickly, it responses by coughing & wants to stall out.  If I increase revs slowly, revs increase yet sounds quite crisp & doesnt miss.
 
I had a quick look for any vacuum leaks, results = negitave (but I havent disregarded the possibility)
 
My first approach was to replace the plugs - which I have done, result = unchanged.
Secondly, I replace the distributor & buttton / rotor, result = unchanged.
 
Tonight I will see if its throwing any fault codes.
 
Next I was going to replace the leads but though it might be the Igniter or coil?  Can anyone suggest or know what I should try next?
 
 
 
 

Hi Carmikey
You don't say if your MR2 is supercharged if it is I would check all hoses from the supercharger for leaks
 
regards 

Hi all
my Mr2 AW11 4agze supercharged, injectors not pulsing this car has been rebuilt. all codes checked fuses relays, and continuity, earths all checked, ECU replaced and the igniter, distributor overhauled, it has good spark and power to the injectors 
it wants to start but will not run because of injectors not pulsing. 
any ideas.
 

Carmikey, you may have picked up some bad fuel.

Fuel, vac leak or TPS sensor would be a good start:)

Just to clarify Scout your separate issue would be best placed in a thread of its own to avoid confusion.
 
Carmikey, so it's misfiring at idle I would remove one plug lead at a time to identify which cylinder/lead/plug/injector is suspect.  Pull a single lead at a time and see if the idle changes, if it doesn't then try the next etc until you remove one and it makes no difference.
 

So it Starts & idles perfectly until thermostat opens up, then the revs drop & sounds like it has a 3 quarter race cam.
Ok... so i tried process of elimination.
i can't find any vac leaks, one by one I've swaped out the coolant temp sensor, didn't change, disconnected tps, no change, & i disconnected / unplugged the idle control valve, all seem to be functioning correctly. Still no change. Still investigating 😠

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The thermostat opening shouldnt effect anything other than the flow of water

I'm thinking maybe when it gets warm, it's not receiving correct signal for air / fuel mixture.. maybe running rich still & its
Choking??

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A clogged fuel filter, possibly. Pressure below threshold could affect the injectors.