Having successfully got an MOT on my Sprint ST 955 today it is apparent that it likes to stall and be troublesome starting when hot. Having done a bit of research (Googling) it seems that the likely culprits are the vacuum hoses leaking and/or the IACV sticking. I know the hoses have been replaced on mine as they are silicon (which I will be replacing anyway) but is there anything else that may cause this issue?
I have used TuneECU and reset the TPS but it still seems the same. From TuneECU the IACV is set at 3 - is that correct?
No. with the bike standing, as normal.nothing connected. Without touching throttle. Start. Leave until fan starts or 12 mins. Thats it.
Ok I did that and it has an uneven idle. Went for a ride of about 20 miles and it will not idle when warmed up. When I got home it would not restart at all although it was starting to fire. I have already replaced the vacuum tubes, cleaned and checked the IACV. So could it be the injectors/fuel rail - after all it has done 112k! I am at a bit of a loss to know what to try next. It will start from cold almost straight away although it takes a second or two of cranking before it catches. Any ideas?
Well I have used it a couple of times and the temp gauge goes up and down. The fan is working but I'm guessing that the radiator should also feel hot when the engine is fully warmed up. Mine doesn't feel hot so I'm thinking it's blocked. Probably by the K seal a previous owner put in it so I need to replace it. Am I right thinking the rad should be hot?
A common cause of bad hot start and and idle on most cars is a failed ECU coolant temp sensor, it causes the ECU to run a richer AFR by default so thats worth checking.