My mates car is running rough on idle and has a tendancy to hunt and cut out occasionally, any ideas what to check first?

Car is a standard 1995 STI apart from a 2.5 decat exhaust

 

Induction air leak, Faulty Dump valve, Dodgey Plug, Maf sensor, Throttle postion sensor, water temp sender. Lambda.
List goes on.
HAs the battery been disconnected for a long time ?? this sometimes highlights thew MAf at fault. Do an Ecu code check to see if any faults are stored.
Then check for leaks, then if possible swap bits off a car that works fine & see if the problem transfers Etc.
Good luck
Dean

 

How do you go about doing an ECU Code Check matey?

 

Also battery wasnt disconnected, my mate only bought the car.

When driving it home it home it started happening, check engine light came on a few times and then later the thing started idling bad and would stall.

 

Best to connect the diagnostic plugs together then under the dash & read the fault code, may give you a better idea

Dean

 

which plugs are they as have never done this, any pics?

 

There are two connectors under the dash down by the drivers footwell, one is green and shaped like a 'T' and the other is black. They should have a yellow multi-block and a blue connector next to them.

Look here http://www.saxonfields.freeserve.co....iag%20Page.htm

for what the connectors look like and what the codes mean.

Cheers

Grim