matt077

iTrader: (2)

Hi all

been driving my scoobie around and found over the pass few days that it idles rough at times and when pulling up to lights or islands it cuts out, other times its fine and idles fine

any ideas to what it could be? had a look over it tonight and cant see anything wrong

scoobydan1985

hello mate is it a classic bugeye hawkeye etc

matt077

iTrader: (2)

sorry mate, its a classic wagon turbo using 1999 running gear

scoobydan1985

im not a mechanic but have had a similar problem try cleaning your idle control valve its by the throttle body and think its got 2 screws in it but seal will need replacing in it as they stretch when removed . it worked for me it gets gunked up with oil dirt etc and stays open slightly giving wrong idle .

JonMc

iTrader: (51)

Look for an air leak - I'm fighting with exactly the same problem on my bug at the moment

apac

iTrader: (2)

It's your Mass Air Flow Sensor(MAF). You have described all the classic signs of a failing sensor, they are weak on the MY99 cars and you need to get it replaced and don't drive the car. They are about £90 and a ten minute job to replace. The sensor is on top of your Air intake pipe. If it fails completely you could blow your engine(sorry for the scare mongering).

matt077

iTrader: (2)

i gave the idle control valve a clean with wd40 as it was dirty but still the same, is there a way to reset it???

any way of testing the maf? i've heard some things about these, still saving up for a simtek ecu set up lol

mach

probably your maf the early ones are prone and expensive(can't strip em down so need to replace whole unit £300 ish new)ESL remap(approx. £500) using a 99 map sensor and have it mapped to that and do away with maf.

THE_WREXER

check your vacumn hoses make sure none of them have popped off or split. I had similar problem on my bug rough idle and wanting to cut out. It was a vacumn hose i knocked off on the intake manifold reconnected idles and runs better

apac

iTrader: (2)

I'll eat my hat if it aint your MAF, and they are not £300 as stated above

r33gts2009

iTrader: (2)

id say maf to mate remove it spray the thin wire inside with carb cleaner a couple of times allow to dry natuarlly dont touch it .... the replace should buy you some time to replace it

bigfarlz

iTrader: (9)

And if there's a cone filter on there get rid, I had to go simtek to eliminate MAF in the end on my00, forever breaking they were.

M19KEU

Sorry for the age old bump but I'm having the same issues with my '99 wagon wrx sti. I've replaced the MAF but only with a patent one ,seemed to get better temporarily but now running like a bag of bolts unless on boost.

I can't find any obvious signs of splits in any vac hoses but they're probably original and show signs of perishing.

Thoughts and suggestions all begged for and gratefully received!

Eprom

My bet it's the MAF, they are fragile on this model, especially if you have modified the air filter set-up.
Reset the engine management using the under dash connectors, if it idle's badly and tries to cut out still take the plunge and order a new MAF.
Have replaced mine 4 times, now at 161,000 miles and still going