15mpg
 

i thought there was something going wrong over the last couple of months, after only getting 38mpg around town, today it dropped to 27 miles to a tenner, it started to missfire bad, i had to drop it into 2nd gear and keep the revs up to get home, i'd already changed the fpr, but looking at the fuel pressure guage it was reading 60psi:eek:, so i had the ball ache of changing the rail yet again, on doing so the fuel pressure has dropped to 37psi:) , i'll see how it goes on fuel now.

lol the fuel pressure regulator has to be one of the most common things to go on the s12. :rolleyes:

really does suck to change it too, glad I have an FSE to go on

Mine has very similar symptoms and since I put the new head on it doesn't like to tick over, I thought it was a dodgy injector I now wondering if it's the fuel pressure regulator.

fit a inline pressure reg mate.

So fitting something like This or This may cure the problem?

bum. sold me car cos of the poor fuel (and ridiculous insurance) and it could have been this :P why didnt I find out this before :trout

Although the wideband showed it as lean on tick over, even crusing at 30 so about -10PSI boost she was reasding and AFR of 13.something i.e. a touch rich :(

My c02 is all over the place on tick over at the moment.

13 is lean mate, i would not run an engine in the 13's on boost:eek: , i'd say about 14's on tickover, although my mk1 din't like to tickover that lean, i think it was an airspeed issue due to the large throttle body and big tubby, but once it was moving it was ok, i got it mapped as lean as i could at 70mph untill it started to misfire, then put some more fuel in, it did around 32mpg on a long run.

minus 10PSI i.e. not on boost, just crawling. For some reason the best I ever got from her was 20mpg and pushed you could get that close to single figures.

Srukk sge gas gone now so nothing much I can do about it :trout

Should be ideally 14.7:1 on a cruise, you could even go leaner.

What type of gauge was it though Wocketfast, a narrow band gauge will indicate too rich even at 14.2:1?

it was my innovative motorsports wideband Martin.

Cool whoever bought his car got a good deal then

didnt sell the wideband with the car ;) only put that in to see what results I got, then I switched it back to the narrow band for everyday use. Didnt want to kill the wideband sensor by running it all the time, and its not the smallest meter ever so finding a perminant home for it would have been a little tricky :P

30PSI - yup she should have been running 14.7:1 but just toddling along off bost she was 13:1. the fuel economy was definatly not what it should have been, and now Im wishing I had got a fuel pressure gauge and checked that too.

Never mind though, I've done 70 miles on the first 1/8th of a tank in my Primera, and the insurance was a whopping £456 cheaper. Oh and she has a proper old man towbar with dual lighting hook up, track day tow car anyone :D

Oh i see. The LM1 is a bit large, my mate has it. Whats annoying is that its pretty much an empty box when you open it. So I decided on the vems one.

But its good to have a wideband that can be easily transferred from car to car

I would like to get the exhaust probe adaptor for it, and the RPM adapter so I can log RPM, AFR voltages etc in the future.

One day I may have an S12 again :(

Fitted this today

http://img.photobucket.com/albums/v4.../IMAGE_006.jpg


Fuel pressure is just over 2 bar on tick over and it's still missing which is better than the lumpy tick over I had before have to wait and see what the mpg is as at the moment I have no brakes.