RodSTI

Too many problems don’t know where to start

I have a 2000 STI, its done 85K. I bought it second hand at 50K. The engine sounded sweet but had a small misfire on idle and felt like it was running lean at about 2500 revs.

About 3 months ago I decided to modify car and have some fun doing track days etc.
I fitted a front mount intercooler and forge dump valve. H&S decat exhaust.
I kept a paper filter but modified the box to allow for the intercooler pipes.
I fitted the temperature sensor through a hole in the inner wing to keep it cool.

After a few weeks the engine started to misfire badly when cold and it was running very rich. I did a compression check and found 2 & 4 to be very low but I had no oil or water problems.

I took the car to an Impreza engine specialist. He stripped the engine and found that the engine was fitted with Legacy head gaskets (Thin ones). The exhaust valves were bent, the rings has lost their strength; the heads were warped and cracked.
He said someone had changed the head gaskets to increase the compression ratio in order to gain some power. This, he thought, was the cause of my problems.

The specialist repaired the engine and I now have it back. It still misfires when cold and it still runs very rich. Sometimes it hunts at idle and sometimes it stalls. Sometimes it is fine.
I have tried to cure it. :-

I replaced the MAF.
I have replaced the Lambda Sensor.
I have replaced the leads.
I have replaced the HT Unit.

I have spent an awful lot of money and I’ve still got a sick car. It is still all over the place. It behaves differently each time I drive it.

What is Wrong?

navydog21@hotmail.com

holly **** there are a few problems there.
can you not take the engine back to the specialist and ask him. hunting could be down to an air leak somewhere.
misfire could be your coil packs.
did you change the plugs(sorry cant see your thread as writing this)

RON

YOu don't mention re-mapping it..... you can;t do all those things without having it done.... unless you're asking for trouble anyway......

Ian

iTrader: (10)

who did you take it to?

RodSTI

If I pull off a small pipe on the mainfold when its hunting at idle the engine speeds up. It seems to be very rich on idle. The exhaust reeks of fuel.

Plugs are now 10mm Alfa romeo. and I fitted a new coil unit.

The engine was rebuilt by someone with a good reputation who came highly recommended. I doubt if there is a problem with the rebuilt engine. I don't want to diss him but I will do a compression test this weekend.

I want to get it re-mapped but its a catch 22 situation. I would like it to be running reasonably well before I get it done.

It's heavily overfuelling at times. Its running on 3 cylinders until it warms up. Is it an injector problem or a MAF problem or a Lambda problem.....all 3 or something else.....

More help please if you can.

fbladerrv900

one word









RE-MAP

finalzero

re-map as everyone has said, you can't do those mods to the engine and not have problems

RodSTI

Problem solved!!!!

I took my car to Zens who were brill. They found that the fuel regulator was faulty causing overfueling on idle.

The only way to check for this is to put a pressure gauge on the fuel line and see if the pressure drops when vacuum is created in the manifold. I hope this helps anyone else whos engines running crap when idling.

scoobyDAZZA

and did Paul tell you it needs a REMAP