PDA

View Full Version : Running rich??



nivram13
28-04-2005, 03:35 AM
Can anyone help me my TN is running rich plugs have black carbon deposits and when the cars running I can smell its running way too rich I have a carby I've read that over certain rev's you can't adjust the mixture any idea's how I can run it leaner? The timing is spot on and everything else seems ok.

turbo_charade
28-04-2005, 07:54 AM
You can only adjust the air fuel mixture at idle my friend. And even that i wouldn't suggest doing without propper equiptment. It seems as though your carburettor might be slowly on its way out. Jet size regulates air/fuel mixture at idle and partial/wo throttle. So unless there is a massive restriction in your intake (eg air filter or choke stuck on) then its unfixable without pulling it apart.

The vacuum lines are a mess on any newer generation carburettor motors but it couldn't hurt to have a look and see if there are any blatent offenders which may have falled off because the lines get brittle.

Get some photo's and ill see what I can find.

How is fuel econemy?

Meph
28-04-2005, 08:19 AM
go to a mechanic that has an exhaust analyser, he/she will adjust it properly

TM-Terror
28-04-2005, 10:50 AM
sounds like the choke has given up, the stock carby's dont seem very robust.
It may not help in this situation, but maybe try some of that Wynns Fuel Injector/Carby Cleaner fuel treatment that you stick in your petrol tank.

benau
28-04-2005, 11:13 AM
only way to adjust the mixtures above idle is to adjust the float level and change the metering jets. is the float level still correct in your carb?

nivram13
28-04-2005, 01:51 PM
How would I know if the auto choke is stuffed????? When I start from cold the engine sits around 2000rpm and after around 5 mins of running sits around 1000rpm which would indicate the choke is working would that be correct. Fuel is economy is never good I will put $20 in about 16ltrs and get around $100ks out of it is that normal or below average??

Meph
28-04-2005, 06:03 PM
This may or may not help you out, but have you tried cleaning the carby out with carby cleaner, i see this helps my laser and its good practice to do this every now and then.

16L per 100k's isnt that good, but depends, if its and auto in the city then maybe its ok, my magna does around 11 or 12 in the city, but its an efi manual.

as for your auto choke working properly, it could be closing most of the way, but not fully, im not sure as how to check

benau
28-04-2005, 06:42 PM
to inspect choke, look down the carby when the engine is hot and running, to see if the choke butterfly valve in the top of the primary barrel is open fully.
If you shopped around the wreckers you could probably find a good replacement 2nd hand carby for less than the cost of a tank of fuel