Hot Engine Misfire

[SparkPlug]

Not to sure where to start with this problem, for the last couple of weeks I have had a misfire with the engine, it only happens when the engine gets hot, say going out for a drive, then letting the car sit for 5min where engine heat can build up, and then starting the engine again which will start a misfire, but if you let the engine cool down by opening the bonnet, then the misfire go's away and the car drives fine.


But what is making this a real pain in the ass to diagnose is there are no fault code coming back from the car, even when the emission light comes on. I have changed Leads, Spark Plugs, Lambada Sensor, and 4 new Injectors, and a new Coolant Sensor yesterday because my radiator fan stopped working, but I'm still getting a misfire from the engine when hot.


Any members here got any ideas because I'm running out of solutions?

 

[SparkPlug]

The only thing I found yesterday when I checked the spark plugs, one of the plugs seemed to have a discoloured insulator, but the tip looked fine so I'm not too sure what to make of that.

 

[N4TH4N]

Try cleaning it up

 

[SparkPlug]

Did that before I put them back.

I just went out for a drive, and when the engine got hot it started misfiring, but this time I had the fault code reader plugged in, and even with the emission light flashing, I still cannot get any error codes from the bloody car.

 

[NorthloopCup]

I've seen a map sensor cause this fault before on a 172.

 

[SparkPlug]

Did that before I put them back.

I just went out for a drive, and when the engine got hot it started misfiring, but this time I had the fault code reader plugged in, and even with the emission light flashing, I still cannot get any error codes from the bloody car.

Really, would that not bring up a fault code of some kind. I also get a engine start problem when it's hot, but I have also changed the Crank Sensor which did not solve the problem.

 

[NorthloopCup]

It didn't on the one I saw this fault on mate. Ran fine when cold/cool but like a bag of s**t when warm.

 

[SparkPlug]

I think I might have found the problem, that discoloured spark plug got taken out today and replaced with a working old one I had laying about, and the car seemed to drive good, I took it out for a drive over to Brands, then stop at the little car park at the top of the hill, let the car rest for 5min for the heat to build up and I did not get a misfire at all, and then repeated this again on the way home, fingers crossed, I might have fixed the problem.