When im driving along and then slow down for lights, junction etc the revs drop so low the engine almost cuts out and sometimes does.
Anyone know what this could be ?
P.S i have had an apexi fc fitted and the revs and idle are on the correct settings

 

How about checking your MAF sensor before anything?

 

Cheers i did suspect that but i thought maf problems are usually irratic idling. I'll get a new one see if it solves the problem

 

dont just go and get a new maf at all! thats all anyone says here, i think its just a scooby thing man! a load of my friends say theyres does the same from time to time, my 98 type r does it too, the mechanic who works on my car said he check maf and its grand, said it happens his wrx ra from time to time as well, nothin to worry bout, thats my 2 cents

 

I sometimes have a similar problem. Try cleaning the idle control valve, if you do a search there will be plenty of threads on this subject.

 

I have a fairly tuned Sti v3 with Apexi fc.
I've been having similar issues ever since, but overcame these by adjusting the throttle cable to 'mechanically' adjust the tickover to about 800/1000 rpm.
Cold start will have the car just ticking over to the point you fear it will stop.
Leave it for 3 mins and the revs pick-up and it will run steady there after no matter what.

I think Jamie B is right. I cleaned mine and reset the solenoid valve on top of the engine when engine was hot and running to set the idel speed to a limited degree, but had to add the cable tweek too.

Graham.

 

Can anyone tell me where the idle control valve is plaese. I done a search but still couldn't find where it is located.
One post i read mentioned cleaning the MAF which i have done and the problem is still there. The MAF did have a slight bit of dust on it which was a surprise

 

there it is there with the crappy little white arrow i did pointin at it!

 

i cleaned my idle control valve too which helped the idle a bit but sometimes she still jumps up and down for a few seconds, dont worry bout it

 

Thanks my irish friend ill give that a try. If it persists im just going to live with it

 

yeh man i tint its just one of those things with scoobs ya know..MAF MAF MAF is all ya hear on this site, wrecks me head!

 

Have you got a VTA dump valve? These can cause idling issues as they can confuse various sensors (including the MAF sensor ).

J