Hi i need some help.

I have a v3 sti ( in a v4 shell) as it had a reconditioned engine along time before i bought it.

I had blown fried two pistons on the car so set about it with my mechanic friend to rebuild then engine.

I couldnt find the same pistons that were already in the car anyway so opted for a set out of the p1 ( they are forged) , anyway the engine got rebuilt with these in them ( new pistons rings too!) and we went the full works and bought new gaskets al round etc etc and put the engine back together , i also bought a new vf24 ihi turbs for it as mine was screwed .

The only other part that has been changed is the turbo air inlet pipe (from the air box, goes uner manifold a blue one from roger clarke) as the old one had disintegrated round the turbo.

The car starts but runs rough as hell , and then cuts out but always starts up again.

Engine management light code said camshaft sensor , so we bought new belts and fitted them with all markings perfectly lined up an timing is correct , but it does the same thing still and same code , it runs rough and cuts out and same code.
I have changed the folowing - MAF sensor, Crank sensor, Temp sensor and camshaft sensor and it makes no difference at all.

I am now quite fed up! , would it need a remap for the pistons ( i cnt imagine it!)
its got normal unleaded petrol in it could that cause it. Theres no kncoks or anything from the engine when its going .

could it be ecu failure?

Please has any1 come across this?? please help

I am inclined to take it to prosport in stockport( near where i live) but if you guys coul shed some light please!

thanks

az

 

and compression is ok!

 

When you say it runs rough, is that as in its got a missfire?. If not check you pipework again you may have an air leak/pipe off etc.

 

nope its not misfiring , its just running rough! and it willl tick over for a nive minute or so but then all of a sudden just cuts out like the revs have dropped too much

 

so if there is an air leak woul it cause it to throw the ecu code out aswell?

 

have you changed the ecu per chance?

 

no ecu is the same as before mate , not messed with anything like that

 

If you don't have the ability to diagnose this problem yourself, taking it to Prosport is probably going to be the quickest way to get it running.

To be honest it sounds like there are more than a few points of concern here. When you say you've put "P1 pistons" in, are you saying you've got brand new P1 pistons of the appropriate size grade, or used ones out of an old engine? Where did the rings come from?

Even if they're new, I have a feeling you'll have altered the compression ratio, and if they're not new, did you ensure that the size grade matched the bores in the block?

An air leak would not cause the crank sensor CEL, and it sounds like the cambelt replacement was more than a little speculative too. If you've replaced the cam sensor and are still getting problems then checking the integrity of the wiring loom would be the next thing to look at.

 

the size grade did match as it was what i was mindful of, and yeah they were second handers but perfect in every way as again i was mindful of it, the rings were fron NPR pistons and were matched to the pistons again ( as i had issues with the first pistons they sent me), yeah cam sensor is 100% replaced with no difference at all and i have had a thought about the wiring loom but its something i have to let mototrsport do as wires are not my forte!!!

 

why would the pistons throw out a cam sensor cel - oesnt really add up tbh

 

I didn't say they would. I was suggesting that, even if you get the CEL issue sorted, you might find further problems down the track.

First thing you should do is have the loom checked. If you're sure the replacement cam sensor is good, it's more likely to be wiring than a bust ECU.

 

yeah sensor is working , iv actually tried my mates 96's estate sensor an it does the same things but its fine on his!!!!


Ill start looking in to the wiring

thanks mate