11 replies to this topic

[leroy26]

theres no getting away from it, it said
12.8 !!!!!

take it i have to turn down my idle speed and weaken the mixture??
new air filter by the way!

[Carlzilla]

Check your plugs first. Always go on plugs! If they're golden brown they're perfect, black is too rich, white is too lean. I don't really trust gunson diagnostic tools.
Adjust mixture if necessary, give it a run. Whip the plugs out and inspect them. Give the plugs a wire brush after each time you inspect them to clean the crap off.
Once you're happy, readjust idle speed. It has nothing to do with fuelling.

[leroy26]

the plugs are currently grey!
and my idle speed is 1500 rpm

Edited by leroy26, 24 March 2012 - 10:40 AM.

[Carlzilla]

If the plugs are grey it indicates it's a bit lean. Hence why I don't like those tools!
Idle speed should be at 800-1000 rpm. 1100 in winter.
Check your ignition timing too if you can. If it's a standard engine I think around 8 degrees BTDC should be right. Double check that figure though lol.

[leroy26]

i know the timings spot on!

will reducing my tickover speed bring the co level down a lot then, cause im fairly sure im not that far out!! shes drives amazingly and as said plug color seems good! there is a bit of soot in the zorst tho!
fprgot to mention i have a stage one kit and shes 998

[Carlzilla]

Most likely haha.
Stick it at 1000, where i always set mine to, or just under.
Soot you'll never get away from, just one of those annoying things!
Have you ever had it on the rollers? Most engines benefit from a tune, mine definitely needed it although it ran fine after fitting a stage 1 to my old 1275, saved me loads on fuel!

[Cerberus]

The gunsons gas tester we've got is pretty much spot on. Pretty much the same reading as the MOT station machines.

Did you calibrate it by leaving it running outside for 2 minutes before using it, and then setting the knob to display 2% in fresh air?

[leroy26]

yeah all calebrated and stuck in eight inch!
guess ill get tweakin!

and no never been set up on rollers

[lrostoke]

same here my gunsons seems pretty accurate with what the MOT man gets.
1500 is on the high side for tickover so won't hurt lower that.
I normally aim for about 3% on ours.

12% might seem high but probably only a couple of turns of the mixture nut.

Edited by lrostoke, 24 March 2012 - 12:06 PM.

[leroy26]

really!!
id be surprised and happy if it that did it!

Edited by leroy26, 24 March 2012 - 12:13 PM.

[gus88]

Mine came in at 12% on the Gunson after I fitted my stage 1 kit, wound the needle down about 3 flats and that brought it to about 2.5%.

I have found that the warm up time of the Gunson really affects the accuracy so now I leave it connected to another battery at home while I go for a drive to warm the Mini up, to make sure the meter's up to temperature.

The car is running very nicely since I tuned it with the Gastester.

[leroy26]

nice one!! cheers m8