popping/banging

[laz11]

I have a 92 4.3 and it has started to make a very loud bang occasionally when starting from cold or within a few minutes of starting. It also happens at med/high revs when giving it full throttle sometimes too, (not neccesarily on the overun). This is occasional rather than often but obviously i am a bit concerned. it drives ok otherwise.

just wondered if anyone would know what this might be? I am planning to take it to my indie soon along with a few other unrelated things that need looking at.

Cheers

[antonyj]

MMM precat heaven, Mine pops too on over run , dont ya love em

[laz11]

Yeah but on start up????

[daxtojeiro]

Can really only be too advanced I would guess for it to pop unless its something drastically wrong and that sounds unlikely if its ok other than that! When tuning the MS ECU on my 5.0L I had an advance of 20Deg BTDC at idle in order to get it to idle nicely, this caused it to pop on start up occassionaly. It could be too weak but thats unlikely on startup, Id check your distributor timing and your vacuum advance pipe work, it could be connected to the wrong hole, this may cause it ,
Phil

[laz11]

daxtojeiro said:

Can really only be too advanced I would guess for it to pop unless its something drastically wrong and that sounds unlikely if its ok other than that! Id check your distributor timing and your vacuum advance pipe work, it could be connected to the wrong hole, this may cause it ,
Phil

Thanks...will look in the bible and check this out. Hope it's not too difficult to figure out as I'm not a techie/wannabe mechanic in the slightest!