fivepint

no worries Nom, every little helps at least we have another angle to look at... i was looking around a few US sites and there seems to be a general theme of o2 replacement under warranty, but a failed or failing o2 sensor seems to cause a very poor idle and increased mpg... which is not what i have only the surging btween 2.5k rpm and 3k rpm?

Cheers

WRX SCOOBY

my car is running fine tony its flying realy i beat a cossie in a drag race and all its just when im cruising around at 3000 revs it slurging very slightly.its the same as the other too lads ,,,would it be the 02 sencer in my car as its a 94 wrx
oh and how do i put a pic up
thanks

fivepint

will delta dash allow me to check my o2 sensor?

Cheers

nom

Yup. And a lot of other things as well.

ozzy

Fivepint,

I had a dodgt 02 sesnor on my car (MY99 RB5). I had a new ECU fitted by the good Dr Banks, but the following day I started getting idling problems.

So, I went back to see John just to check the ECU. We refitted my original ECU and it did the same thing. We then did a Deltadash run and saw the O2 sensor sitting at a steady voltage. No nice wave pattern at all. Eventually convinced my Dealer to replace it after 2 months.

If your O2 sensor is knackered, then I'd expect you to see idling problems too. Are you?

I'm running a std AE801 ECU just now and do get surging problems as you describe. When John gave me a Tek3 to play with I never experienced the problem

Deltadash or a Select Monitor would show you problems with your O2 sensor.

So, could be MAF, O2 or even ECU

Stefan

fivepint

thx for the info Stefan, im not experiencing idle probs at all, apart from the odd stumble (no where near stalling) in traffic. My Maf was replaced under warranty about 3km miles ago, but the car has surged since ive had it (12mths approx) its not a running prob as such, more a minor annoyance... its feels like something that could quite easily be sorted and thats wahts more frustrating

BTW any one with delta dash coming to Dublin soon?!?! LOL

Cheers

WRX SCOOBY

5pint were in dub are u do u think u would be able to look at my car and let me know ur opinion thanks

fivepint

WRX im on the northside, but u would be better off going to Paul in Macspower Motorsport (he's irelands Pete croney ) he would have better equipment to diagnose with, AFAIk hes becoming an EcuTek dealer too, but it sounds like uve got the wrong ECU/Engine combo... check out www.macspower.net for more info...

cheers

fivepint

@Mr DBM, do u know anyone with delta dash that may be able to log the "surging" then we could at least post the info so the techy boyz could anylise it? I dont have access to a laptop at the mo (my mac was stolen) BTW will delta dash run on Mac OS?

Cheers

MrDBM

fivepint - nope sorry, no delta dash around these parts...

MrDBM

@fivepint - agree that this is probably an easy fix, given the right kit, and importantly - the right expertise to use and interpret...

i'm in for a service next month so i'll mention it to the dealer, they're not really *that* helpful, but I'll try and get them to examine the car under surge conditions.

If I find anything even slightly useful, I'll post it

SCOSaltire

my thoughts:
i have the surging problem
put in a new maf sensor - did not sort it, tho did sort the rather low idle speed (750-800, is now 850 ish)

dealer showed me a bit of paper from subaru - says the surging is due to pulsing of the air in the manifold as the turbo is not up to speed.

I am sure this got worse after 30k mile service.

I also have the car dropping revs - like a subtle misfire - on idle. you only notice it if u touch the car - u can feel it shudder. I am going to see about this tomorrw - am getting some idle control thingy cleaned. I will mention the 2500 - 3000 revs thing again.

I have also noticed that it does a major jerk - like another misfire - when floored in 2nd gear (when it climbs the revs quickly).

I cant help but feel that this is all connected...

fivepint

have they looked at your 02 sensor?

WRX SCOOBY

5pint whats an o2 senser ,and were are they on the car ,,are they dear
thanks
allan hudson

fivepint

bttt

ozzy

The O2 sensor is the Oxygen sensor and helps control how efficiently the engine runs. It detects Rich or Lean mixtures in the exhaust gases where a chemical reaction in the gases causes different voltage measurements from the sensor. The ECU reads the voltages and works out if it's Rich or Lean then adjusts the fueling appropriately.

On later cars the sensor is in the downpipe.

Edited to add they're about £120 from your Dealer

Stefan

P.S. Just to remind everyone that I've already had my 02 sensor replaced and it didn't fix any surging/hesitations. If your sesnsor is sh@gged, then I'd expect really rough idling and a sooty tailpipe (as it'll be running stinking rich).

[Edited by ozzy - 8/28/2002 4:13:46 PM]

wrxmark

In my mechanic days the Ford Sierra injected models surged all the time. This was caused by an oil breather pipe being routed through the air intake system and then causing an oily build up around the lowere edge of the butterfly in the throttle housing. So the car would surge as if hunting for air/fuel.

Although Ford used to fit an expensive kit to solve the problem we used to remove the pipe from the throttle housing and clean the butterfly spotless with petrol or a solvent based cleaner.

A cheap fix that if done every service keeps the butterfly clean and the motor surge free.

My WRX is surging and this weekend the intercooler is coming off and the throttle butterfly is going to get its first clean in 46,000 miles I suspect.
I have done it as a matter of routine servicing on all my cars and the tick over always without fail improves.
I have no doubt the scooby will be the same.

nom

I have a few doubts.
Mine was worse after I cleaned everything up

WRX SCOOBY

let us know how u get on and how to do it thanks