[mike_turbo]

what may cause a car to run lean?

 

[SUSSEX REIMS]

what may cause a car to run lean?

I think a weak/faulty fuel pump could cause u to run lean.

 

[mike_turbo]

okie doke, what about a f*cked fuel filter?

 

[NumptyScrub]

If it's an inline filter (I think most are) then a clogged one will cause lean running, due to not being able to pass as much fuel through. You'll notice it top end first as that's where the highest demand is.

I don't think they are either that expensive, or that difficult to replace though, so it's a fairly simple "fix" just to replace it regardless

PS I have never changed a fuel filter on my Evo so I'm no expert on the matter though

 

[mike_turbo]

cheers guys

my cars been a bit sluggish for a while, took it for service and ive been told its running lean, so plugs being replaced and fuel filter, hope this sorts it!

 

[xlr8]

did they check:
the fuel pressure & air-fuel ratio
the fuel pressure regulator was/is working ok

 

[mike_turbo]

no idea! i shall ask

 

[OlDirty]

Could be a knackered lambda sensor mike.

 

[Oli]

if you've had new plugs check them to see if there's sign's of detonation or running lean.

check out this website for what colour means what

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

 

[Reims]

what may cause a car to run lean?

Lots of exercise?

 

[LeeLegend-TME139]

mike how long have you owned a evo?

 

[mike_turbo]

mike how long have you owned a evo?

:rofl: bout 2 years :blush:

 

[xlr8]

Could be a knackered lambda sensor mike.

surely that'll make it run rich.....(?)

 

[mike_turbo]

thanks for the link and advice too guys - basically the car has felt like it has been hesitating like f*ck for a while now, i put this down to plugs but they are less than a year old but i ruled them out, but we are gonna try and rule out the easy ideas first - see if that helps

 

[oli goon]

mike,

there could be quite a few things that cause this:-

MAF fault
inlet piping fault (BOV most lilekly)
ecu fault
fuel pump fault
fuel piping fault
fuel filter fault
injector fault

 

[mike_turbo]

bugger

cheers oli, gives me an idea of where to start - lets hope its just the fuel filter!

 

[Turbo_Steve]

I'd get some diagnostics done on it before you start changing stuff.

Get a fuel pressure meter stuck on the end of the rail, get a wideband lambda stuck on the car and get the behaviour analysed, then go from there, as the nature of the lean running will indicate which direction to persue the problem

 

[Traction Man]

thanks for the link and advice too guys - basically the car has felt like it has been hesitating like f*ck for a while now, i put this down to plugs but they are less than a year old but i ruled them out, but we are gonna try and rule out the easy ideas first - see if that helps

Mine was hesitating like hell after I had a boost controller fitted. I took it to WRC Tech last week, it was running dangerously lean between 3k & 5.5k, luckily Chris spotted that the pipe had been knocked off my fuel regulator.

All is well now.