Running Rich. Big problem?

[little ghost]

Couple of days ago i fitted standard dv back on the car, but left the recirc pipe off (because i was told i could.)

Car ran amazingly- less lag, better acceleration, more responsive BUT, slowing to traffic lights or whatever, the idle was dipping to about 400 rpm and nearly dying before it picked up again and was idling like a bag of spanners.

I've been told that running the dv like this is making it run rich, which would explain why a cabbie stopped next to me at lights the other day asked me if i knew my exhaust was on fire!- and it was popping and flaming at 35 mph!

I'm confused because the car seemed to be running so much better like this- but obviously running too rich ain't good news.... or is it?

What i want to know is, what would happen if i continue to do this (and don't just say you'll burn more petrol and need a rebuild)
But mainly why the car's performance was improved.
And if it's possible to change the mixture easily.

Thanks. :roll:

 

[ard1ey]

When you say you put the original DV back on, you've still got the old recirc pipe that goes to the intake pipe blocked, right?

If you run the car too rich then you're wasting petrol as you said and you can get bore wash, where the oil film inside the cylinder gets diluted by the excess petrol. This can lead to accelerated bore/piston ring wear (so you'll need a rebuild ).

Changing the mixture usually means some electronic cleverness like S-AFC, I don't think the 'R has anything like a base mixture screw.

Have you tried putting all the recirc pipework back as it was originally, to see if it stops lighting up the road?

 

[JamesB]

Yeah i did that for a month or two - just to make it sound nice and was supprised at the performance increase. The downsides you mentioned is caused iirc by the small hole in the dv which leaks out boost - why, I have not idea, they just do. If your REAL keen, weld up or thread and put in a stumpy bolt to stop the bleading - OR buy an aftermarket dv.

Just a note, it only overfuels off throttle at low rpm really so thinning of the oil isnt a huge prob unless you leave it like that for a while.

 

[little ghost]

Thanks. Hmmm, i've not blocked up the standard dv pipe. There's the intake (big fat pipe) vacuum (skinny pipe) and the one that comes off the side (meant to go to the air intakepipe between the filter and tubby). I know this one is the cause of it all cos on idle if i block the pipe with my hand it runs as smooth as silk- but then, no performance increase and no nice but random flames.

I even tried covering it half over to see if i got both a nice idle etc....and flames and performance, but it just seemed to run as normal??

Think i should just hook it up like standard before i break something!? :roll:

 

[Innovate Performance]

If you disconnect the dump valve onthe side that goes to the air intake pipe then you will get the noise and the just block the pipe up that goes to the air intake.

You wont gain performance and you wont get the flames.

 

[little ghost]

Air intake is blocked up, pipe from metal elbow of dv is left open and venting to atmosphere- this is what is causing the flames and overfueling...

Yet anyone else i have spoke to says they haven't had this problem.

 

[Innovate Performance]

do you get the problem when it is connected up like it is as standard.

 

[little ghost]

Although i'm guessing, i'll wager not cos like i say, if i cover the pipe...all is normal.

Balls to it- i'll just hook it up like it should be, some things aren't meant to be tampered with. :roll: