fueling questions
fueling questions
Author
Discussion

johns3

Original Poster:

93 posts

259 months

Thursday 1st September 2005
quotequote all
Hi all!

My S3C is overfuelling a bit so i was thinking about superchips/piggyback ECU's to sort the problem. Is it possible to superchip my S3C or can i rule out superchips and focus on piggyback ECU'S. Any reccomendations other than the dastek unichip which i know tends to be very good. Im located in Swindon, Wiltshire anyone know of any good garages who can put it on the rollers and do the job?

doddze

1,302 posts

268 months

Thursday 1st September 2005
quotequote all
why is it overfueling?? and how do you know it is.... curious as mine had a similar problem but I seem to have got on top of the problem by changing a few sensors and the fuel regulator..

sotonS2

14,709 posts

267 months

Thursday 1st September 2005
quotequote all
Usual suspects are any sensor which puts the ECU into LOS mode or whose output could affect the mix ratio. For example, Throttle Pot / Air Flow Meters / Engine Coolant Sensor / Idle Speed Control Valve.

Haven't got an S3C myself so don't know whether a duff Lamdba sensor could cause these symptoms.

doddze

1,302 posts

268 months

Thursday 1st September 2005
quotequote all
yep Lambdas could affect mid range but not idle or WOT as the EECIV has different maps for this.

I have just changed my TP which has run ok till yesterday and it has stopped my pops and bangs which is a sign of overfuelling.... as you say safe modes are rich mix modes..

johns3

Original Poster:

93 posts

259 months

Friday 2nd September 2005
quotequote all
hmm interesting stuff. The fumes smell rich and im getting some pops and bangs. Had a big one the other ay when i put my foot down, released a large flame from the exhaust. Never a good sign! may nee to start looking for faults. Ile is sitting a little high lately once the engine is warm (about 1100rpm). How o i know which part to replace (throttle pot, lambda sensor etc.) should i just replace everything or can a fault code reader tell me the problem?

doddze

1,302 posts

268 months

Friday 2nd September 2005
quotequote all
too expensive just to replace them all.....

you could try diconnecting things one at time... ie TP and see if it makes a difference.... If this doesn't make any diffeence or of course makes it worse reconnect and move on... dont forget to disconnect both Lambda sensors at once!! Interesting your getting the pos when you put your foot down... mine were when I lifted off....



>> Edited by doddze on Friday 2nd September 17:38

johns3

Original Poster:

93 posts

259 months

Friday 2nd September 2005
quotequote all
the pops and bangs are usually when i lift off and slow down on the gearbox. Put i went to overtake a car the other day and must have been a surge of fuel or something there was a large bang and a huge flame shot out the back. I must invest in "the bible" (mechanical not religious) I been running this car for way too long without owning one.

doddze

1,302 posts

268 months

Friday 2nd September 2005
quotequote all
could even be a faulty fuel regulator.... I picked one up from a scrappy for a tenner....

normally for the car to be running rich there must be a sensor down somewhere if not the ECU would/should correct it....

It is probably best to get the mix tested before you go to too much pulling around...then you know how bad the mix is if it is bad....

are there any other signs of a problem apart from high tickover? any hesitation? flat spots? does it rev round to the red line freely??

johns3

Original Poster:

93 posts

259 months

Friday 2nd September 2005
quotequote all
not really. Sometimes it feels like its holen back not giving me full power. Think that might be safe driving mode? apart from that its normal as far as im aware.

tvrgit

8,489 posts

281 months

Friday 2nd September 2005
quotequote all
are you sure it's sparking properly on all cylinders? If you have a slightly oily plug you'll get the engine missing slightly, with the fuel possibly not igniting properly until it's in the exhaust port or manifold causing the pops and bangs - would also explain the hesitation and then flames on acceleration.