NotoriousREV

sh1te is how my car is running at the moment.

It's very hesitant and is even occasionally spitting back through the air filter coming off a closed/light throttle and very lumpy (hunting) on a light cruise.

Dawes AFR is showing blue light all the time till ~3500rpm then it goes into Knight Rider on speed, first starting by flashing all the lights, then the top3, then the top 2 then finally (at 80mph) just the red is flashing (all on a light throttle). Foot to the floor shows the big blue again but it's detting like a b'stard at full boost and >4500rpm. Tick over is also erratic, either a steady 1200rpm, or 800rpm and chugging or 800rpm and fine.

Currently driving off boost till I figure it out as I can't afford a rebuild right now!

My initial thought was maybe the Lambda is fubared (due to the readings on the AFR) or is the Lambda correct and the fuelling is knackered due to a dodgy MAF, or indeed is it one of a million other things.

Other things that may help: coil packs were replaced with used units from APi about 2 months back and this is new, full tank of fuel (didn't do it before the fill up, has done it ever since). Haven't reset ECU or checked for error codes, but the CEL hasn't been on.

HEEEEEEEELLLLLLLLLPPPPPPPPPPP!

Peanuts

iTrader: (15)

could be bad juice, in which case try a diagnostic and reset once a fresh tank is in, quick road test will highlight if the problem is still there.

APIDavid

iTrader: (4)

CEL doesn't always come on, which is helpful !! Firstly do an ECU check then depending upon what it does or doesn't tell you;

I'd go Lambda first, then MAF.

Alternatively have you got a tankful of fuel plus rainwater? If you filled up on a rainy day just after the tanker had been at the fuel station it's quite common for the first few customers to get a mix of water and fuel.

ALL fuel station tanks have water in them unless they are only a week old and when 6000 fresh gallons gets lobbed in the silt gets stirred up and hey presto.

Proving that is impossible of course but it does, I assure you, happen. Ask any AA / RAC guy.

Good Luck David APi Engines / APi Impreza

willy

i`ve had water in petrol before...
Very common.
Saab even recommend a periodic addition of water emulsifier in the petrol tank to burn it/clean off.

*****

Peanuts

iTrader: (15)

sounds like a good idea *****

NotoriousREV

Funnily enough, the "delivery in progress" signs were out but not quite out, if you know what I mean so either the tanker had just been or was just about to get there.

Peanuts

iTrader: (15)

take it easy for the rest of the tank, or chuck some NF in there.
refill and reset your ecu then tentatively try to push the car a bit on fresh juice

NotoriousREV

I'm not even halfway through the tank yet

Off boost for another 100 miles, then.

Thanks for the advice guys!

Peanuts

iTrader: (15)

chuck some booster in if you do few miles,
I had a bad batch once but do 600 miles a week so it was peasy

NotoriousREV

Should be through it by Monday, hopefully.

NotoriousREV

and suddenly, with 1/3rd of a tank to go, it's running perfectly

minor_threat

LOL! Damn pesky machines, just as unpredictable as Microsoft Windows and women and lottery numbers and weather and 'Santa's Happy Sack Lucky Dips'.

DeanF

iTrader: (1)

The lambda can when cream crackered can be Ok for a while & then back to bag of Sh!te, Mine had the same symtons, finally bit the dirt bought one put it on & It never came back ..

Dean

NotoriousREV

Yup, back to ****e running today. noticed that AFR is displaying blue light when ignition is on but engine not running. It's got to be a dead sensor

Jolly Green Monster

iTrader: (4)

yes imho..

try disconnecting the lambda sensor in the downpipe and see if it runs any better.

might need to reset the ecu after disconnecting, and it might throw a cel but should run better.

If it is reading rich with engine off then it will most probably be leaning out to try and get it to stoich whcih will be very very lean if the sensor is showing rich with engine off.