Thread: Running rich?

Hi all,

I have a 93 D1 V8 fuel injected.

Chasing other dramas, I was reading here where, I think tombraider said, the Rover V8 was well known to soot spark plugs.

So my question is: I've occasionally thought my engine was running rich? How do I go about working out if the mixture is correct?

I'm about to put ina new set of plugs as they're sooty and I think two have given up completely, after about 20,000ks.

GQ

dead serious... had a heap of stuff happen in the begging of my quiet time (phone rang, computers beeped, mobile rang, alex cried someone at door you know the drill) anyway twas a bit much for the connection between the brain and reality and she slipped out of gear for a bit... (more lube should help slow that problem)

The evidence is here http://www.aulro.com/afvb/showthread.php't=34245

anyhow..

yeah MAF=Mass air Flow or for the purpose of this thread the stuff that does the same job as a MAF there being more than one way to skin a cat and all..

Sooty plugs are one of four main causes (assuming by soot you mean a light coating of carbon that is easily removed by wiping)

1. over fuelling (may also be from a blocked air filter)
2. wrong temp for the plug (too cold plug)
3. too long between services
4. prolonged cold idle/excessive idle times/something else causing hunting at idle

1. is hard to square up on an EFI donk without brainy tools
2. is easy (but not cool for prolonged use)on a v8 keep 2 old plugs in(clean them first), replace 2 with one step hotter and 2 with 2 steps hotter the last 2 put 2 of the same type in (use diagonally opposite sides of the engine to eliminate external temp influences) it may run a little funny but after about 500k you will have enough info to tell you what you need to change. whichever plugs came up cleanest are your bet.
3. just needs em changing more often, I used to check mine every service and get say 30-40k from a set of plugs depending on how good the fuel was and how I was driving.
4. is pretty much self explanitory, dont idle it more than you need to, and give it some nice long cruisey runs... Bug one was prone to fouling when SWMBO used it for just running the groceries and movies to and from the shops (70 second drive tops).

There is one adjustment you should be able to do with just a screwdriver and a spanner and thats to adjust the idle port air bleed but this will effect idle as well..

more on that later if changing the plugs doesnt help.