Whoops I melted 6 pistons!
Discussion
Well after two years of abuse the Soarer finally dies, dodgy fuel pump causing it to run lean under load finally saw the end of the 1JZ lump, when it suddenly started breathing really badly!.
Today it was stripped down to reveal 6 melted pistons
Proper job 
This engine had done 60k miles when it went in & has been running 1.5-1.8 bar of boost & 450bhp plus for 2 years without much bother so I can't complain & up until now, it has never been apart!
Remarkably it was still starting & running really sweetly, you'd never have known anything was wrong unless you looked at the breathers!
Interestingly they'd only melted on the inlet side not the exhaust side, no idea why. It's new engine time (I was changing it anyway)
Today it was stripped down to reveal 6 melted pistons
Proper job This engine had done 60k miles when it went in & has been running 1.5-1.8 bar of boost & 450bhp plus for 2 years without much bother so I can't complain & up until now, it has never been apart!
Remarkably it was still starting & running really sweetly, you'd never have known anything was wrong unless you looked at the breathers!
Interestingly they'd only melted on the inlet side not the exhaust side, no idea why. It's new engine time (I was changing it anyway)
It's detonation damage and those weak thin edges take a pounding. You'll probably find termite holes in the top ring land and vertical scratches above the top ring.
ETA, why does the piston crown look really lumpy? Is it a truly awful casting? Or is it an oil and carbon mix?
ETA, why does the piston crown look really lumpy? Is it a truly awful casting? Or is it an oil and carbon mix?
Edited by Boosted LS1 on Sunday 22 February 23:40
You have a detonation problem, as you say you had a fuel pump problem I'd recommend that you install a fuel pressure switch up by the fuel rail & have it turn off the engine if you have problems. I would also check the water pump to make sure it can send enough coolant to the heads. An overbore, new pistons & a new head gasket will fix the engine.
That is the unsophisticated yet cheap solution, there is certainly a lot more you could do as others suggest, but that will depend on whether or not you can afford it.
That is the unsophisticated yet cheap solution, there is certainly a lot more you could do as others suggest, but that will depend on whether or not you can afford it.
cptsideways said:
I'm putting a whole new lump in, its cheaper than a set of gaskets! The joy of 1JZ powers The engine is being donated to another lad who's going to re-work it & fit it into an E30
Found the fuel pump wiring issue, a stupidly simple fault
That's all very well, but I'd still add a low fuel pressure switch that helps avoid engine failure. The engine is being donated to another lad who's going to re-work it & fit it into an E30 Found the fuel pump wiring issue, a stupidly simple fault
GavinPearson said:
cptsideways said:
I'm putting a whole new lump in, its cheaper than a set of gaskets! The joy of 1JZ powers The engine is being donated to another lad who's going to re-work it & fit it into an E30
Found the fuel pump wiring issue, a stupidly simple fault
That's all very well, but I'd still add a low fuel pressure switch that helps avoid engine failure. The engine is being donated to another lad who's going to re-work it & fit it into an E30 Found the fuel pump wiring issue, a stupidly simple fault
If anyone can think of a good way to do it I'm all ears
cptsideways said:
GavinPearson said:
cptsideways said:
I'm putting a whole new lump in, its cheaper than a set of gaskets! The joy of 1JZ powers The engine is being donated to another lad who's going to re-work it & fit it into an E30
Found the fuel pump wiring issue, a stupidly simple fault
That's all very well, but I'd still add a low fuel pressure switch that helps avoid engine failure. The engine is being donated to another lad who's going to re-work it & fit it into an E30 Found the fuel pump wiring issue, a stupidly simple fault
If anyone can think of a good way to do it I'm all ears
Steve
cptsideays, i know my above coment might sound daft, and it was a little, but there are good reasons to look into these belt driven pumps.
first of all, you can run about 100+psi baseline presure! and there is plenty of room left in these pump for even higher presures if you boost ref the regulator. as the pumps flow grates are directly linked to the engine speed your pumps are not working at 100% effort from the moment you turn the ignition key. you do however require MASSIVE fuel regulators to keep the presure down at lower engine speeds. and if you loose a belt its pretty serious. dont know if you could toast an engine from it....
still might be worth looking at if you are having problems with electronic pumps.
Chris.
first of all, you can run about 100+psi baseline presure! and there is plenty of room left in these pump for even higher presures if you boost ref the regulator. as the pumps flow grates are directly linked to the engine speed your pumps are not working at 100% effort from the moment you turn the ignition key. you do however require MASSIVE fuel regulators to keep the presure down at lower engine speeds. and if you loose a belt its pretty serious. dont know if you could toast an engine from it....
still might be worth looking at if you are having problems with electronic pumps.
Chris.
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