spark plug melted! help!

[mitchracer]

About 2 weeks ago i noticed a stutter/hesitation from 2800rpm up to 3100rpm but i had let my fuel go quite low until the light went on which is the 1st time i had done this, so i filled the car up and when i drove off the stutter had gone so i thought nothing else about it and put it down to that maybe.
2days after this it did it again for a couple minutes until it warmed up, so i thought id check my spark plugs, and they all looked fine so i decided id get a new set soon anyway.
At the weekend when i was fitting a new clutch i spoke to a mate about the problem and he said check the spark plugs again, this is when i found that 1 of my spark plug tips had melted! and also there was a small crack on the part holding the little tip and these were denso iridium spark plugs! am lucky the broken part hadnt fallen into the bore and im sure the end is melted not broken so there wouldnt have been a loose bit there.
So i put a different spark plug in at the garage just to get me to the gf and the car drove lovely all the way there, not stuttering or anything, obviously i drove it sensibly after finding a melted plug already.
the next day i drove home and the car was stuttering again, so i pulled the plugs when i got home and they all looked good but i changed them for my old plugs which i was running before i forged the engine which worked fine and now the car is stuttering like mad with no power at all.

bit of background on the car is
3000miles into running forged tdo4 240hp at 1.5bar on emange blue and i do not abuse this car as it has cost me so much

somebody please help me out, am starting to loose heart with this car after so much bad luck and money it is costing me

 

[starletgtturbo1]

About 2 weeks ago i noticed a stutter/hesitation from 2800rpm up to 3100rpm but i had let my fuel go quite low until the light went on which is the 1st time i had done this, so i filled the car up and when i drove off the stutter had gone so i thought nothing else about it and put it down to that maybe.
2days after this it did it again for a couple minutes until it warmed up, so i thought id check my spark plugs, and they all looked fine so i decided id get a new set soon anyway.
At the weekend when i was fitting a new clutch i spoke to a mate about the problem and he said check the spark plugs again, this is when i found that 1 of my spark plug tips had melted! and also there was a small crack on the part holding the little tip and these were denso iridium spark plugs! am lucky the broken part hadnt fallen into the bore and im sure the end is melted not broken so there wouldnt have been a loose bit there.
So i put a different spark plug in at the garage just to get me to the gf and the car drove lovely all the way there, not stuttering or anything, obviously i drove it sensibly after finding a melted plug already.
the next day i drove home and the car was stuttering again, so i pulled the plugs when i got home and they all looked good but i changed them for my old plugs which i was running before i forged the engine which worked fine and now the car is stuttering like mad with no power at all.

bit of background on the car is
3000miles into running forged tdo4 240hp at 1.5bar on emange blue and i do not abuse this car as it has cost me so much

somebody please help me out, am starting to loose heart with this car after so much bad luck and money it is costing me

water normaly does this if it touches the tip

 

[mitchracer]

really? so could this be headgasket problem? i used a 1.2 headgasket and arp headbolts and i didnt build it myself btw

 

[starletgtturbo1]

i thought you ment electrode side. in that case it sounds like detonation, bad fuel, ignition timming

 

[mitchracer]

thanks for the quick reply btw, what would be 1st step in finding out how to sort the problem, and what damge could this have caused? i have to have the head pulled back off anyway because my valve seals are nakered so will the damage show when i pull this off?

 

[MARK@CMBAUTOS]

sounds like detonation, bad fuel, ignition timming

x2 sounds like its running lean but what plugs u using ? heat range ?

 

[dac69er]

if it is only that plug then could be an injector problem. if its getting that hot to melt the plug then it could easily cause alot more damage if you keep driving it like that. also check the whole of the ignition system to make sure its all ok.

 

[mitchracer]

saying about the injector, im sure 1 of my injector has gotten louder within the last couple of weeks, but why would it effect the 2800-3100rpm only? up until i tested it yesterday after changing the plugs again. i am not using the car until i have the problem sorted anyway, il get the injectors tested though and check through the ignition system

 

[Chris@CCM]

sounds like dett

 

[corofin12345]

timing id say... something not right.. as for spark plug exploding in plug hole, im stumped.. i can only imagine water been the culprit but it sounds like theres a few issues

 

[MARK@CMBAUTOS]

sounds like dett

x2

 

[George611]

Running miles to hot in that cylinder so id agree with dac69er about maybe an injector fault. Id get the injectors checked and if they are fine then go back to your mapper and get him to check the igniton against the fuel, the revs its happening at sounds like when your coming on boost so makes sense if its a map issue.

 

[mitchracer]

Thanks for the input lads, I'm buying another set of injectors 1st so I can see if that is the problem, once I have done this I will be taking it to my mapper anyway to see what they put it down to, oh! And 1 other thing I noticed while checking the wiring for ignition was that my dizi cap had come loose so whether it hadn't been tighted enough and had moved? Could this cause the problem?

 

[dark_knight]

dizzy culprit

@mitchracer: if your dizzy cap was loose then that could only be part of the fault. in essence, this would only mean that there was poor contact between the igniter and the plugs thus a poor spark. it does not, however, conclusively explain the possibility or running lean..

 

[dac69er]

Thanks for the input lads, I'm buying another set of injectors 1st so I can see if that is the problem, once I have done this I will be taking it to my mapper anyway to see what they put it down to, oh! And 1 other thing I noticed while checking the wiring for ignition was that my dizi cap had come loose so whether it hadn't been tighted enough and had moved? Could this cause the problem?

was the cap loose or the distributor itself?

 

[Sheldon]

if it is only that plug then could be an injector problem. if its getting that hot to melt the plug then it could easily cause alot more damage if you keep driving it like that. also check the whole of the ignition system to make sure its all ok.

im witht this guy,

 

[mitchracer]

Just the cap was loose mate

 

[mitchracer]

Just thought I'd give every1 an update, have put some more injectors in (not new) but I gave them a good old clean through with carb cleaner and this seems to have sorted the stutter problem but I am still not 100% confident at just driving it like normal again so will get it checked with my mapper aswel so I can finally put an answer to this melted spark plug.
Thanks to every1 for their input

 

[whiteglanzav]

]check the injector if its fucked it may not be supplying sufficiant fuel causing it to overheat and melt the spark plug

edit: just read last post lol

 

[Rev]

Missing may also be leads - So far I have found a plug gap on cylinder 3 of 1.5mm so it seems the iridiums have melted tips as they went in at .8mm.
I am trouble shooting and still haven't changed the plugs but with new high performace leads there is a very big difference to smoothness and acceleation no missing other than at idle.